• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.181-187
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• 2009

In this study, a runoff hydrograph and runoff volume were calculated by using the kinetic wave theory for small urban watersheds based on the concept of low impact development(LID), and the effective imperviousness was estimated based on these calculations. The degree of sensitivity of the effective imperviousness of small watersheds to the impervious to pervious area ratio, infiltration capability, watershed slope, roughness coefficient and surface storage depth was then analyzed. From this analysis, the following conclusions were obtained: The effective imperviousness and paved area reduction factor decreased as the infiltration capability of pervious area increased. As the slope of watersheds becomes sharper, the effective imperviousness and the paved area reduction factor display an increasing trend. As the roughness coefficient of impervious areas increases, the effective imperviousness and the paved area reduction factor tend to increase. As the storage depth increases, the effective imperviousness and the paved area reduction factor show an upward trend, but the increase is minimal. Under the conditions of this study, it was found that the effective imperviousness is most sensitive to watershed slope, followed by infiltration capability and roughness coefficient, which affect the sensitivity of the effective imperviousness at a similar level, and the storage depth was found to have little influence on the effective imperviousness.

• The Journal of Korea CHUNA Manual Medicine
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• v.5 no.1
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• pp.183-193
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• 2004

Objective : Acupuncture therapy is known as a effective method to pain control including elbow area pain. To make clear about effectiveness of acupuncture affecting to recovery of grip power for the patient with elbow area pain, we compare the patients recieved acupuncture treatment to people with elbow pain unrecieved acupuncture treatment. Material and Methods : This clinical study has been carried out with 30 cases of patients with elbow area pain. 20 patients divides into two groups were treated by acupuncture in MPS with elbow area. Two groups were radial area pain group and ulnar area pain group. The other 10 people with elbow area pain working a resturant in Ilsan were no treatment. The study was applicated and estimated grip power before 1 st treatment and after each treatment for 4 days. Results : 1. In the radial area pain group, the acupuncture treatment is more effective than no treatment (p<0.007). 2. In the ulnar area group, the acupuncture treatment is more effective than no treatment (p<0.037). 3. The effectiveness of acupunctrue treatment is no differnce between radial area pain and ulnar area pain(P<0.529) 4. In the elbow area pain group, the acupuncture treatment is more effective than no treatment (p<0.001). Conclusion : These results shows that acupuncture treatment is effective in elbow area pain.

• Journal of the Korean Institute of Navigation
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• v.2 no.1
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• pp.15-34
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• 1978

This paper deals with the study of the effective reflecting area of the land targets for the improvement of the map of the Radar Simulator, through the analysis of the pictures on P.P.I Scope. It is very important to anticipate the effective refiecting area of land marks, either forinterpretation of radar scope or for simulating accurately the radar scope, but has seldom been studied theoretically or experimentarily, especially on the stand point of simulating the radar scope. Most of the maps of Radar Simulator in use are made without consideration of the effective reflecting area of land marks, so that the P.P.I. Scope of the Radar Simulator may show much different pictures from the actual shore line and other targets. This paper has derived the following conclusiions by experimental procedures. 1. The effective area of the land target greatly varies according to the gradient of the contours, roughness and material of the land surfaces, so that simulator maps of uniformly coated land taret practically used now many be effectively improved by varying the intensity of the land marks proposed in this paper. 2. The intensity of the land targets on the P.P.I. is also related much to the distance from the radar, so that the precalculation of this effect may results in a much simulated P.P.I. picture improved. 3. If the ambient condition is constant, the intensity of the picture increases as the height of the targets is increased.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.584-585
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• 2010

A numerical simulation was performed to investigate the internal flow characteristics in gas turbine nozzle by the variation of flow area of the nozzle. In general the area of turbine nozzle is chosen by the most substantial factor on performance improvement of turbine at the first stage. In the performances test through CFD analysis for three types of nozzle with conventional, enlarged and reduced area, reduced one with effective flow area (EFA) was the most efficient. That is the minimum effective value within EFA limit defined by the manual of technical order had a good performance. It is useful to avoid the low power problem in the test of performance after maintenance and overhaul of turbine engine.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.162-165
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• 2001

In industrial practice, caliber design in shape rolling depends on the designer's experience, which in general is obtained through costly trial-and error process. on-line model which is relations of mean effective strain, roll force and area reduction is derived from finite element process simultion in bar rolling with three rolls.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.2
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• pp.49-56
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• 2018

The use of highly absorptive materials in cement-based materials is increasing for internal curing purpose. However, calculation of correct absorption capacity of such materials is not easy, which leads to change in the effective water-to-cement ratio of cement paste by either absorbing or releasing water. In this study, effective absorption capacity of a highly absorptive material was found using isothermal calorimetry. Moreover, the effect of specific surface area was investigated. It was found that the method was capable of finding effective water absorption capacity of activated carbon fiber. For the activated carbon fiber used in this research, the effect of specific surface area was negligible because the high BET surface area was due to micropores less than 1nm, which does not affect the rate of hydration curve. Thus, the effective absorption capacity of such materials can be found successfully using this method.

• Ocean Systems Engineering
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• v.3 no.1
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• pp.71-77
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• 2013

The effective tracking area of ultra short baseline (USBL) systems strongly relates to the safety of autonomous underwater vehicles (AUVs). This problem has not been studied previously. A method for determining the effective tracking area using acoustic theory is proposed. Ray acoustic equations are used to draw rays which ascertain the effective space. The sonar equation is established in order to discover the available range of the USBL system and the background noise level using sonar characteristics. The available range defines a hemisphere like enclosure. The overlap of the effective space with the hemisphere is the effective area for USBL systems tracking AUVs. Lake and sea trials show the proposed method's validity.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.122-129
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• 2006

The linear compressor has lately attracted considerable attention because of its low power consumption and excellent efficiency. For an efficient design, it is necessary to develop an analytical model of the linear compressor. The effective flow and force areas are important parameters to describe the behavior of the linear compressor, which are used to determine the mass flow rates through the valving systems and the forces on the valves, respectively. It is not easy to estimate these parameters because shapes of the valve systems of the linear compressor are so different from those of tile conventional valve systems. In this paper, we suggest method to measure experimentally the effective discharge flow and force areas of the linear compressor and analyze valve characteristic to apply the experimental results to their theoretical model.

• Journal of Animal Science and Technology
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• v.61 no.1
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• pp.18-27
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• 2019

With South Korea's limited capability of feed production because of its relatively small cultivable area, the country is pushed to depend on foreign feed imports despite the immensely fluctuating price of corn. Hence, intensive efforts to increase the total cultivable area in Korea like extending of farming to mountainous area is being practiced. Corn was planted in Goesan County, a mountainous area in the country. Grain and stover were harvested separately in three harvest periods: early-harvest (Aug 8), mid-harvest (Aug 18), and late-harvest (Aug 28). The nutrient composition such as dry matter (DM), crude protein (CP), crude fat (EE), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), and non-fibrous carbohydrates (NFC) was determined after harvest. Effective degradability (ED) of the major nutrients (DM, NDF, ADF, and CP) were measured through in vitro fermentation of rumen fluid from Hanwoo (Korean cattle). pH, ammonia-N concentration, volatile fatty acid (VFA) concentration, and gas production were periodically measured at 0, 3, 6, 12, 24, 48, and 72 h. Corn grain showed higher nutrient content and ED than stover. It also had higher gas production but its pH, ammonia-N, and total VFA concentration were lower than corn stover. The best nutrient composition of corn grain was observed in early-harvest (high CP, EE, NDF, OM, NFC, and low ADF). Early-harvest of corn grain also had high effective degradability of dry matter (EDDM), effective degradability of neutral detergent fiber (EDNDF), effective degradability of acid detergent fiber (EDADF), and total VFA concentration. On the other hand, the best nutrient composition of stover was observed in mid-harvest (high DM, CP, NDF, and low ADF). EDDM, EDNDF, and EDADF were pronounced in early-harvest and mid-harvest of stover but the latter showed high total VFA concentration. Hence, early and mid-harvested corn stover and grain in a mountainous area preserved their nutrients, which led to the effective degradation of major nutrients and high VFA production.

• Journal of Korean Library and Information Science Society
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• v.6
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• pp.105-140
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• 1979

This study is an attempt to present a model of the effective service area for branch library system planning in Dae Gu city as one of large urban public libraries in Korea. This model is built up through the analysis of the distribution of population and characteristics of community structure, based on the standard for the branch library system of a public library. The results are summarized as follows: 1. Under the circumstances of this country, each radius of the effective service area for branch libraries are as follows; $1{\sim}1.5km$. is adequate for the central library and major branches; 1km. for neighborhood branches; $0.5{\sim}0.8km$. for sub-branches. 2. Population within the radius of the effective service area of a given branch may range from 80,000 to 100,000 for major branches, from 50,000 to 60,000 for neighborhood branches, and from 20,000 to 30,000 for sub-branches. 3. The radius of the outer boundary for the effective service area may be between 4km. and 5km. from the heart of the city, and the inner boundary, 13.km. 4. Areas with the radius between 2km. and 3km. from the heart of the city may be selected as the most effective locations for branch libraries, and between 3km. and 4km. as the next priority. 5. The number of service areas may be 14, that is, 7 major branches(Sinam, Sinchun, Susung, Daemyung, Naedang, Dalsung, Rowon), 2 neighborhood branches (Pyungri, Nambu), and 5 sub-branches(Chimsan, Sangiuk, Bongduk, Hyomok, Dongchon)