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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Korean Journal of Agricultural Science
Journal Basic Information
Journal DOI :
CNU Journal of Agricultural Science
Editor in Chief :
Volume & Issues
Volume 38, Issue 4 - Dec 2011
Volume 38, Issue 3 - Sep 2011
Volume 38, Issue 2 - Jun 2011
Volume 38, Issue 1 - Mar 2011
Selecting the target year
Study on waxy corn - XIII. Botanical characteristics and crude incomes analysis of Daedukchal 1
Lee, Hee-Bong ; Lee, Moon-Sub ; Bok, Tae-Gyu ; Choi, Yun-Pyo ; Cha, Hui-Jung ; Hong, Bum-Yong ; Kim, Hyo-Gi ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 1~6
Daeduckchal 1 waxy corn hybrid including check was planted and compared with domestic leading vatiety on agronomic characteristics, traits related to table gualities and crude income. Stem and ear height of Daeduckchal 1 among used hybrids were intermediate and stem diameter was also similar to other hybrids. Days to tasseling of this hybrid needed 56 days which was slightly shorter than check hybrid, Yeonnong. Ear length of CNU-H2 was longer than Yeonnongchal as 21.7 cm, while Chalok 2 was 14.1 cm. Number of tillers per plant of this hybrid were higher than Chalok 2 but lower than Yeonnong. Pericarp thickness of CNU-H2 and CNU-H3 were similar to Yeonnon. In sugar content, Daeduckchal 1 was intermediate level as 11.7 brix(%). Marketability of Daeduckchal 1 was the highest among used hybrids and crude incomes was also high.
Promising line development of sweet sorghum by gamma-ray treatment
Lee, Moon-Sub ; Bok, Tae-Gyu ; Choi, Yun-Pyo ; Lee, Hee-Bong ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 7~10
In order to develop the new Miscanthus varieties for biomass, characteristics of collected materials were surveyed. Also, they were treated with S-azide(Sodium-azide) and DES(dethyl sulfate) for promising lines and 0.2% Colchicine for polyploidy, respectively. CNU-J1 line induced with chemical, DES and S-azide treatment showed shorter than others in stem height and stem diameter. CNU-N1 line treated with 10 mM DES showed earlier than non-treated lines in flowering as 7days. Among selected lines, the CNU-J1 line was crossed with DB-1 selected as a superior line and their hybrid was expected to be high in biomass than others. Especially, CNU-W1 line treated with 2.5~5.0 mM DES showed heading in M1 generation.
Construction of a full-length cDNA library from Pinus koraiensis and analysis of EST dataset
Kim, Joon-Ki ; Im, Su-Bin ; Choi, Sun-Hee ; Lee, Jong-Suk ; Roh, Mark S. ; Lim, Yong-Pyo ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 11~16
In this study, we report the generation and analysis of a total of 1,211 expressed sequence tags (ESTs) from Pinus koraiensis. A cDNA library was generated from the young leaf tissue and a total of 1,211 cDNA were partially sequenced. EST and unigene sequence quality were determined by computational filtering, manual review, and BLAST analyses. In all, 857 ESTs were acquired after the removal of the vector sequence and filtering over a minimum length 50 nucleotides. A total of 411 unigene, consisting of 89 contigs and 322 singletons, was identified after assembling. Also, we identified 77 new microsatellite-containing sequences from the unigenes and classified the structure according to their repeat unit. According to homology search with BLASTX against the NCBI database, 63.1% of ESTs were homologous with known function and 22.2% of ESTs were matched with putative or unknown function. The remaining 14.6% of ESTs showed no significant similarity to any protein sequences found in the public database. Gene ontology (GO) classification showed that the most abundant GO terms were transport, nucleotide binding, plastid, in terms biological process, molecular function and cellular component, respectively. The sequence data will be used to characterize potential roles of new genes in Pinus and provided for the useful tools as a genetic resource.
Effect of pre-planting liming fertilization in peatmoss based substrates on plug seeding growth of 'Red Madness' petunia and changes in soil chemical properties
Lee, Poong-Ok ; Lee, Jong-Suk ; Choi, Jong-Myung ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 17~23
This research was conducted to investigate the influence of application rate of liming fertilizers on changes in soil chemical properties and growth of 'Red Madness' petunia in plug production. To achieve this, dolomite (DO) with 0, 1.0, 3.5, 8.0 or 13.0
and calcium carbonate (CC) with 0, 2.0, 2.5, 3.0, 3.5, or 4.0
were incorporated into peatmoss + vermiculite (1:1, v/v) during the root substrates formulation. The treatments of 3.5
of DO and 2.5 or 3.0
of CC had acceptable ranges of pH and EC in soil solution such as 5.6~6.2 and 0.7~1.0
, respectively. The faster rising of pH was observed in root media containing CC rather than those of DO. This indicates that the solubility of CC is higher than DO. The soil Ca concentrations in all treatments of CC were 1.8 times as high as those of DO. The treatments of 3.5 or 8.0
of DO had the highest soil Mg concentrations, but all treatments of CC had lower soil Mg concentrations than control treatment indicating that additional application of Mg fertilizers are required. The elevated application rate of DO or CC resulted in the increase of fresh and dry weight. But plant heights were not influenced by application of liming fertilizers. The results of tissue analysis showed that application of DO or CC influenced the
, Ca and Mg contents, but not influenced the contents of other nutrients such as N, P, Fe, Mn, Zn and Cu.
A change of soil properties and forest vegetation present in burned areas in Geyjoksan, Daejeon metropolitan city
Lee, Hang-Goo ; Park, Gwan-Soo ; Lee, Sang-Jin ; Kim, Kil-Nam ; Park, Beom-Hwan ; Ko, Young-Woong ; Yoon, Jun-Young ; Kim, Hyoun-Sook ; Lee, Sang-Hyuk ; Kang, Kil-Nam ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 25~30
This study was conducted to investigate changes on burned areas after a forest fire in Geyjoksan which occurred in April 2000. Both soil physicochemical properties and vegetation present were analyzed in burned and unburned sites of pinus densiflora according to two slope aspects(south and north-facing slopes). The results of the analysis are as follows. The appearance species of vegetation were 21, 15 and 18 for burned site, burned site-1 and burned site-2 of pinus densiflora community respectively, indicating that the occurrence of forest fire and slope aspects affect vegetation appearance. The pH values at 0~10cm soil depth of unburned and burned sites of pinus densiflora community were 5.04 and 5.12 respectively with no significant difference between them. Mean organic matter, total nitrogen and available P also had no significant difference. This results indicate that the forest recover its former pH, total nitrogen, mean organic matter and available P over time after a forest fire. North-facing slope had relatively higher soil water content thus implying that its pH values of soil lower than south-facing slope. On the other hand, south-facing slope had high organic matter and available P content of soil as compared to north-facing slope. With south facing slope having high water contents, humus was accumulated due to slow organic matter decomposition. The pH values also decreased due to organic acids from humus. However, we observed that organic matter and P concentration in soil increased.
Analysis on the status of community forest in overseas
Yoon, Jun-Young ; Park, Gwan-Soo ; Kang, Ho-Duck ; Kim, Se-Bin ; Lee, Joon-Woo ; Lee, Hang-Goo ; Lee, Sang-Jin ; Park, Beom-Hwan ; Jang, Hyeon-Su ; Sung, Yong-Joo ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 31~38
This study was conducted to build frameworks for a guideline of community forest projects with respect to ODA of Korea (Official Development Assistant) in forest fields. Community forestry is a worldwide phenomenon which began in developing countries such as Nepal, Gambia, Guinea, and Indonesia and has been gradually recognized as an effective measure for ODA in forestry areas from ODA/DAC countries and the other international donors. This study investigated types of community forest status, mechanisms of community forest project conducted by ODA/DAC countries or the other international donors, and CFM (Community Forest management) success factors. As a result of our study, there are different types of resource users, having different economic and social status, perspectives, knowledge systems, values, understandings and objectives in community based forestry. Consequently, the clear forest tenure systems enabling communities to get motivated for the projects, the most appropriate agroforestry systems in different countries, capability of community to manage forest and etc must be considered carefully when the community forest project are implemented for ODA of Korea in order to gain successful results from ODA in forestry fields.
Seasonal occurrence of major moth pests and their environmental friendly control in pear orchard
Seo, Mi-Ja ; Park, Min-Woo ; Yoon, Kyu-Sik ; Jo, Shin-Hyuk ; Jo, Chang-Wook ; Shin, Hyo-Seob ; Kwon, Hye-Ri ; Kang, Min-A ; Kim, Sae-Hee ; Yu, Yong-Man ; Youn, Young-Nam ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 39~44
The changes in major moth populations were monitored by sex pheromone traps in pear orchards at Yuseong-Gu, Daejeon from 2008 to 2010. Among four major moths, Grapholita molesta and Caposina sasakii occurred most frequently. Their occurrences peaked 2 to 3 times during the growing season from May to September. G. molesta was exceptional, occurring until September. For the environmentally-friendly control of these moths, 9 control materials including insect pathogenic bacteria and environmentally-friendly agricultural materials, were examined on the larva of 4 kinds of moth and sprayed on pear leaves in the field. As the generalized results of bioassay, Bacillus thuringiensis subsp. kurstaki and Sophora flavescens extract were shown to have better control effects than any other control material.
Diagnosis of Bovine Leukemia Virus (BLV) infection using PCR and ELISA techniques in Holstein dairy cattle
Jeong, Hang-Jin ; Yu, Seong-Lan ; Lee, Jun-Heon ; Do, Chang-Hee ; Shu, Guk-Hyun ; Ryoo, Seung-Heui ; Sang, Byung-Chan ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 45~50
This study was conducted to investigate the farm situation about bovine leukemia virus(BLV) infection that greatly influence productivity in dairy cattle and compare the accuracy of diagnosis for BLV infection between PCR and ELISA techniques. Blood samples of 193 heads from 5 herds in Chungnam and Chungbuk area were used to analyze BLV gene and serum, and the results were obtained as follows. The amplified BLV gene in dairy cattle by PCR technique resulted in 226 bp, 596 bp and 434 bp, respectively, for gag, pol and env, which were well amplified. The infection rates of BLV virus diagnosed by PCR and ELISA techniques ranged from 80.55 to 100% and from 22.22 to 86.95%, respectively, and the infection rates among 5 herds were significantly different in both methods (P<0.05). Further, the average infection rates of 5 herds were 87.05 and 63.21%, respectively, for PCR and ELISA techniques. Kappa statistics for examining consistency of diagnosis by PCR and ELISA techniques showed 0.246, which represents low consistency. Consequently, PCR based BLV technique was considered as a corrective measure for diagnosis of BLV infection in Holstein dairy cattle.
Analyses of single nucleotide polymorphisms and haplotypes of BoLA-DRB3 gene in Holstein and Hanwoo
Jeong, Hang-Jin ; Yu, Seong-Lan ; Hoque, M.R. ; Lee, Jun-Heon ; Do, Chang-Hee ; Ryoo, Seung-Heui ; Sang, Byung-Chan ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 51~63
BoLA (bovine leukocyte antigens) have been known as gene complex related with bovine diseases and immunological traits. This study was conducted to find out the characteristics of BoLA-DRB3 gene related to mastitis and BL(bovine leukocyte) from 280 cattle [193 animals of Holstein cattle and 87 animals of Hanwoo]. As a result, five PCR-RFLP types (b, d, e, f and g) using HaeIII restriction enzyme, three BstYI restriction patterns (b, d and e) and eight RsaI restriction types(b, d, f, I, j, n, o and w) were identified. Moreover, we identified new d' type (
/22), having one more cutting site by BstYI enzyme than d type allele and n' type (
/11) having one more cutting site by RsaI enzyme than n allele was additionally identified. Next, we identified 53 SNPs in BoLA-DRB3 exon2 from 280 cattle. SNP frequency and heterozygosity of Holstein and Hanwoo were investigated in all the SNP genotype. These results might be based on research for identifying marker associated with bovine diseases.
Analysis of brain protein expression in developing mouse fetus
Han, Rong-Xun ; Kim, Hong-Rye ; Diao, Yun-Fei ; Woo, Je-Seok ; Jin, Dong-Il ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 65~70
Development of mouse fetus brains can be defined morphologically and functionally by three developmental stages, embryo day (ED) 16, postnatal stage one week and eight weeks. These defined stages of brain development may be closely associated with differential gene expression rates due to limited cellular resources such as energy, space, and free water. Complex patterns of expressed genes and proteins during brain development suggests the changes in relative concentrations of proteins rather than the increase in numbers of new gene products. This study was designed to evaluate early protein expression pattern in mouse fetus brain. The mouse brain proteome of fetus at ED 15.5, and 19.5 was obtained using 2-dimensional gel electrophoresis (DE). Analysis of the 2-DE gels in pH 3-10 range revealed the presence of 15 differentially expressed spots, of which 11 spots were identified to be known proteins following MALDI-TOF analysis; 3 spots were up-regulated and 8 spots were down-regulated in the mouse fetus brain at ED 15.5. UP-regulated proteins were identified as MCG18238, isoform M2 of pyruvate kinase isozymes M1/M2, isoform 2 of heterogeneous nuclear ribonucleoprotein K, heterogeneous nuclear ribonucleoprotein H2, creatine kinase B-type, 40S ribosomal protein SA and hemoglobin subunit beta-H1. Down-regulated proteins were putative uncharacterized protein, lactoylglutathione lyase and secreted acidic cysteine rich glycoprotein. Our results revealed composite profiles of mouse fetus brain proteins related to mouse fetus development by 2-DE analysis implying possible roles of these proteins in neural differentiation.
Expression analysis of Porcine Endogenous Retroviruses (PERVs) in Korean native pig organs
Oh, Hyung-Gil ; Jung, Woo-Young ; Yu, Seung-Lan ; Lee, Jun-Heon ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 71~77
Pigs have anatomically and physiologically very similar to human and because of this, pigs are the possible xenotransplantation donors for human organs. PERVs (Porcine Endogenous Retroviruses) are known to be one of the possible obstacles for using porcine organs regardless of the immunological barriers. In order to understand the expression patterns of PERVs in Korean native pigs, we investigated PERV expressions in porcine liver, heart, spleen, and lung samples. After RNA extraction, two types of specific PERV envelope genes (ENV-A and ENV-B) were amplified using specific primers by RT-PCR. The results indicated that the variable PERV expressions were observed in inconsistent patterns among animals and tissues. The PERV expressions were verified with semi-quantitative real-time PCR with three replicates. Even though, these results confirm the previous findings that the PERVs were differentially expressed between animals and tissues. These results also give some valuable information for xenotransplantation when using the Korean native pigs as the organ donor.
Effect of season, tissue position and color on content of amino acids in cabbage (Brassica oleracea)
Oh, Il-Nam ; Choi, Seung-Hyun ; Park, Suh-Young ; Lim, Yong-Pyo ; An, Gil-Hwan ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 79~86
The contents of free amino acid in cabbage cultivars originated from China and Korea were measured to determine the quality for taste and nutrition. The experimental variables were season (spring-sowing and fall-sowing), leaf position (inside and outside), and the cabbage color (green and red). Eighteen free amino acids were detected at the range of 0-38 mg/g dry weight. The most abundant amino acid was serine(0-128 mg/g). Alanine, aspartate, glutamate, asparagine, histidine, and proline were relatively rich at 2-12 mg/g dry weight. Glycine were significantly increased in spring-sowing cabbages by 2-fold but proline was reversely decreased by 7-fold. The inside parts of cabbages contained significantly more alanine, glutamate, glycine, isoleucine, serine, and valine than the outside ones. The higher contents of isolecuine, leucine, proline, and valine were observed in the red cabbages than the green ones. The significant cross effects of season-color and position-color were also observed, indicating the red and the green cabbages were differently affected by season and tissue position.
A time-course study of flavonoids in buckwheats (Fagopyrum species)
Lee, Min-Ki ; Park, Suk-Hoon ; Kim, Sun-Ju ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 87~94
Flavonoid contents of common buckwheat (cv. Kitawase) and tartary buckwheat (cv. Hokkai T 8, Hokkai T 9 and Hokkai T 10) were determined by high-performance liquid chromatography (HPLC). Moreover, they were measured at different plant developments such as 10, 18, 20, 22 and 30 days after sowing (DAS) and with plant parts including leaf, stem and flower harvested at 30 DAS. Total flavonoids including chlorogenic acid, four kinds of C-glycosylflavones (orientin, isoorientin, vitexin, isovitexin) and rutin of tartary buckwheats (range of 44.2-54.7, mean 44.2) were found 35% higher than those of common buckwheat (28.9 mg/g dry wt.). Among them, rutin was measured above 80% of total flavonoid contents. The other flavonoids (chlorogenic acid and four kinds of C-glycosylflavones) presented the highest level at 10 DAS and decreased according to plant developments. On the other hand, rutin content of Kitawase presented the highest level (33.6 mg/g dry wt.) at 22 DAS and decreased up to 30 DAS. Rutin content in tartary buckwheat temporarily decreased from 10 to 18 DAS and then reversely increased up to 30 DAS presented the highest level as 'U' curve. In Hokkai T 10, rutin content was found the highest level (53.8 mg/g dry wt.) at 30 DAS. In different plant parts harvested at 30 DAS, rutin content of leaf (range of 42.8-68.0, mean 57.0) was 5.3-fold higher than that of stem (range of 8.0-15.9, 10.8 mg/g dry wt.), regardless of cultivar. Significantly, rutin content (78.7) in the flower of Kitawase was 1.8 times higher than in the leaf and 9.8 times in the stem. Especially, chlorogenic acid content (14.6 mg/g dry wt.) in the flower of Kitawase was 63-fold higher than in the leaf, and 20-fold in the stem.
Evaluation of fiberization of rice hull by autohydrolysis conditons
Lee, Young-Ju ; Jung, Woong-Ki ; Sung, Yong-Joo ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 95~100
In the present study, effects of autohydrolysis treatment on the properties of rice hull were investigated. Two temperature condition such as
and thee treatment time such as 15 min, 30 min and 45 min were applied for autohydrolysis treatment. The pH of extract after autohydrolysis treatment decreased as increasing of the temperature and the treatment time. The ash content and the lignin content of rice hull were not decreased by the autohydrolysis treatment. The structure of rice hull after autohydrolysis treatment became more weak, the better efficiency of the fiberization with PFI-Mill was shown for the autohydrolysis treated rice hull with the higher temperature and the longer treatment time.
Analysis of work times and postures occurring relating to stone channel work in forest engineering
Yeom, In-Hwan ; Choi, Yeon-Ho ; Kim, Myeong-Jun ; Kweon, Hyeong-Keun ; Lee, Joon-Woo ; Kim, Je-Su ; Park, Bum-Jin ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 101~108
In forest work, working conditions are very hard to improve. The proper distribution of work time and good posture is believed to bring about direct improvements such as accident prevention. On this, this study has analyzed forest workers' posture and their working hours in order to improve their working conditions in stone channel work. Authors has chosen several core elements of stone channel work to focus on, which include stone masonry, excavation of bed, moving stone, directing work, choosing stone, and breaking stone. The ratio of real working time over total working time was shown as 84.6%. As for the time ratio of each elemental work over the real working time, the stone masonry was 60.4%, the directing work was 15.1%, moving stone was 12.1%, choosing stone was 7.1%, breaking stone was 3.3%, and excavation of bed was 2.0%. According to the analytical results provided by OWAS, the ratio of category III (Work posture has a distinctly harmful effect on the musculoskeletal system) has shown that moving stone turned out 65.2%, choosing stone was 61.5%, stone masonry was 46.1%, breaking stone was 14.3%, excavation of bed was 12.5% and directing work was 6.8%. Furthermore, the ratio of category IV (Work posture with an extremely harmful effect on the musculoskeletal system) has shown that excavation of bed turned out 37.5%, breaking stone was 28.6%, stone masonry was 27.3%, choosing stone was 7.7%, moving stone was 6.1% and directing working was 4.5%. These results are expected to be utilized for the improvement with respect to both working methods in the stone channel work and the workers' working posture.
Potentiality of urban forest roads as an environment for enhancing physical fitness
Jeon, Yong-Jun ; Choi, Yeon-ho ; Kim, Myeong-Jun ; Lee, Joon-Woo ; Park, Bum-Jin ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 109~113
The purpose of this study was to examine the potentiality of urban forest roads as an environment for enhancing physical fitness. Six male university students participated in the study as subjects. The subjects walked on an urban forest road for 30 minutes. As a control experiment, they also walked on a national park trail for 30 minutes. Subjects' heart rates were monitored during the walks to calculate the ratio of the average time their heart rates were within the target range (from 60% to 80% of the maximal heart rate) for Enhancing Physical Fitness. After the walks, images of the spaces were analyzed using the semantic differential (SD) method. During the walk on the urban forest road, subjects' heart rates were within the target range 63.3% of the time, and lower than the target range 36.7% of the time. During the control experiment on the national park trail, subjects' heart rates were within the target range only 23.3% of the time, and higher than the target range 76.7% of the time. From the spatial perception evaluation using the SD method, subjects' comfortable and natural feelings when they were on the national park trail were significantly greater than when they were on the urban forest trail, but there were no differences in terms of other SD descriptors, such as friendliness and likeability. The results of our study indicate that the urban forest road provides a good environment for walking to enhance physical fitness. Although not as close to nature as national park trails, urban forest roads offer similar natural environments and have a high potentiality for serving as leisure spaces for urban residents who seek physical activities.
Heat transfer of green timber wall panels
Kim, Yun-Hui ; Jang, Sang-Sik ; Shin, Il-Joong ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 115~120
20% of total energy use to sustain temperature of building inside. In this reasons, researchers effort to improve the thermal insulation capacity with new wall system. Using appropriate materials and consisting new wall system should considered in energy saving design. OSB(Oriented strand board), Larch lining board used to consist wall system.
Larch lining board has tongue & groove shape for preventing moisture. Comparing with gypsum board and green timber lining board as interior sheathing material, temperature difference of Green timber wall system was bigger than temperature difference of gypsum board wall system. This aspects indicate that Green timber wall system was revealed higher thermal insulation property than gypsum board wall system. Gypsum board portion transfer heat easily because temperature difference gradient of gypsum board wall system was smaller than OSB wall system. Total temperature variation shape of G-4-S and G-6-S show similar model but, temperature variation shape in green timber wall portion assume a new aspect. The purpose of this study was that possibility of thermal insulation variation and new composition of wall system identify to improve thermal insulation performance. In the temperature case, this study shows possibility of improving thermal insulation performance. Humidity, sunshine and wind etc. should considered to determine building adiabatic properties.
Development of HST electronic control system for combine (II)- Outdoor tests for control Characteristics -
Seo, Sin-Won ; Huh, Yun-Kun ; Lee, Je-Yong ; Lee, Chang-Kyu ; Bae, Keun-Soo ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 121~128
I/An electro-hydraulic transmission having advantages of convenience, safety, simple linking and high power, and an electronic control system were designed and fabricated. In this study, characteristics of the control system were investigated through outdoor tests for evaluation of installation of the system on a combine. Major findings were as followings. 1. Experiment for performance evaluation of the control system was conducted on concrete road. With steering lever in neutral position, driving HST swash plate and left/right wheel speed increased in proportion to driving lever angle. In case of steering control, steering swash plate angle changed in proportion to steering lever angle. This should cause increase in outer wheel speed, but it was observed that HST swash plate was controlled toward neutral to maintain the speed before steering. As a result, speed before steering was maintained despite the change in outer wheel speed by steering HST swash plate angle change. 2. It was observed that the HST system enabled steering with outer wheel maintained at constant speeds while inner wheel speed decreased, which was more stable than conventional mechanical links. In addition, for the selected 5 criteria, experiment showed satisfactory results and it was judged that installation on real vehicle would be feasible. 3. The control system showed response property of appropriate forward/reverse movement and lift/right steering, without causing any problems during experiment on concrete. Result of response property experiment on field operation also showed appropriate control over forward/reverse movement and left/right steering.
Comparison of incoming solar radiation equations for evaporation estimation
Rim, Chang-Soo ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 129~143
In this study, to select the incoming solar radiation equation which is most suitable for the estimation of Penman evaporation, 12 incoming solar radiation equations were selected. The Penman evaporation rates were estimated using 12 selected incoming solar radiation equations, and the estimated Penman evaporation rates were compared with measured pan evaporation rates. The monthly average daily meteorological data measured from 17 meteorological stations (춘천, 강능, 서울, 인천, 수원, 서산, 청주, 대전, 추풍령, 포항, 대구, 전주, 광주, 부산, 목포, 제주, 진주) were used for this study. To evaluate the reliability of estimated evaporation rates, mean absolute bias error(MABE), root mean square error(RMSE), mean percentage error(MPE) and Nash-Sutcliffe equation were applied. The study results indicate that to estimate pan evaporation using Penman evaporation equation, incoming solar radiation equation using meteorological data such as precipitation, minimum air temperature, sunshine duration, possible duration of sunshine, and extraterrestrial radiation are most suitable for 11 study stations out of 17 study stations.
Engineering properties of permeable polymer concrete for pavement using powdered waste glass as filler
Sung, Chan-Yong ; Kim, Tae-Ho ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 145~151
This study was performed to evaluate the void ratio, compressive and flexural strength, and permeability coefficient used powdered waste glass,
, recycled coarse aggregate and unsaturated polyester resin to find optimum mix design of permeable polymer concrete for pavement. The void ratio and permeability coefficient of permeable concrete for pavement was decreased with increasing the powdered waste glass, respectively. The compressive strength and flexural strength was increased with increasing the powdered waste glass, respectively. In addition, this study found out that required amount of binder was decreased with increasing the powdered waste glass. This fact is expected to have economical effects during the use of powdered waste glass in the manufacture of permeable polymer concrete for pavement. Therefore, powdered waste glass and recycled coarse aggregate can be used for permeable polymer pavement.
Spatio-temporal change detection of land-use and urbanization in rural areas using GIS and RS - Case studies of Yongin and Anseong regions -
Gao, Yujie ; Kim, Dae-Sik ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 153~162
This study analyzed the spatio-temporal change detection of land-use and urbanization in Yongin and Anseong regions, Kyunggi Province, using three Landsat-5 TM images for 1990, 1996, and 2000. Remote sensing (RS) and geographic information system (GIS) techniques were used for image classification and result analysis. Six land-use types were classified using supervised maximum likelihood classification. In the two study areas, the land-use changed significantly, especially the decrease of arable land and forest and increase of built-up area. Spatially, the urban expansion of Yongin region showed a spreading trend mainly along the national road and expressways. But in Anseong region the expansion showed 'urban sprawl phenomenon' with irregular shape like starfish. Temporally, the urban expansion showed disparity - the growth rates of urbanized area rose from the period 1990-1996 to 1996-2000 in both study areas. The increased built-up areas were converted mainly from paddy, dry vegetation, and forest.
Operation rule curve for supplying urban instream flow from reservoir
Noh, Jae-Kyoung ; Lee, Jae-Nam ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 163~172
To provide the operation rule curve for suppling instream flow to urban stream from reservoir, the Soho reservoir with watershed area of 7.4
and total water storage of 2.58
was planned at the headwaters of the Daejeoncheon. Daily streamflow was simulated and using the simulated streamflow and desired instream flow, the operation rule curve by Senga method was drawn and evaluated through reservoir operation. Senga method is derived by accumulating the differences between streamflow and desired instream flow adversely. Water storages were simulated on a daily basis to supply urban instream flow from Soho reservoir, but the amount of supplying instream flow to urban stream was not nearly increased comparing with that of normal operation that does not used the rule curve. Thereafter the new simulation-based operation rule curve was derived and applied to supply instream flow from Soho reservoir. In normal operation, the amount of instream flow was shown to 15,000
/d, but it was increased to 27,700
/d in withdrawal limited operation using the new derived rule curve, in which the applicability of this rule curve was proved. Also comparing with the flow duration curves at station just before urban Daejeoncheon stream without and with upstream Soho reservoir, the 95th flow was decreased from 1.64 mm/d to 1.51 mm/d, and the 355th flow was increased from 0.17 mm/d to 0.30 mm/d. Monthly streamflows during October to March were increased from 10.6~24.1 mm to 24.1~34.0 mm with the increasing rate of 141~227%.
The analysis on governmental subsidizing program for the distribution cost of agro-food exportation
Kim, Kyung-Phil ; Kim, Soung-Hun ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 173~181
Korean government has executed some programs to support producers and/or exporters for the promotion of agro-food exportation. Especially, governmental subsidizing program about the distribution cost for agro-food exportation shows positive effects. However, this subsidy should be changed or partly abolished due to the low effectiveness of subsidy. The goal of this paper is to analyze the effectiveness of governmental subsidy and to present the agro-food products with the low effects of subsidizing program. As the results of analysis, the subsidy for several products, including Ginseng drinks, Paprika, and Chrysanthemum, might be considered to be stopped due to low effectiveness.
Investigating multi-attributes for expanding new renewable energy in agricultural sectors : Applying the analytic hierarchy process
Lee, Sang-Ho ; Park, Jae-Hong ;
Korean Journal of Agricultural Science, volume 38, issue 1, 2011, Pages 183~190
The paper is to analyze multi-attributes for expanding new renewable energy in agricultural sectors which have environmental, technical, economic, and social factors consisting of 15 attributes which have both positive and negative impacts. We applied the analytic hierarchy process (AHP) to data from opinion polls. As a result of the AHP survey, the overall results indicate that the respondents more weight on economical factor than environmental, technical, and social factors for expanding new renewable energy. At the lowest level, a comparison of individual 15 attributes within three factors shows that fixed cost highest in multi-attributes, followed by operating cost, technical superiority. To achieve the public acceptance about expanding new renewable energy in agricultural sectors, the policy-makers should take all relevant factors into account through the decision-making process by the public opinions.