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Evaluation of 226Ra analysis methods using a gamma-ray spectrometer and a liquid scintillation counter (감마선분광분석기와 액체섬광계수기를 이용한 226Ra 분석법 비교 연구)

  • Ju, Byoung Kyu;Kim, Moon Su;Kim, Hyun Koo;Kim, Dong Su;Cho, Sung Jin;Yang, Jae Ha;Park, Sun Hwa;Kim, Hyoung Seop;Kwon, Oh Sang;Kim, Tae Seung
    • Analytical Science and Technology
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    • v.28 no.3
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    • pp.228-235
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    • 2015
  • The efficiency and applicability of the solid phase extraction disk method in a 226Ra analysis were examined by the gamma ray spectrometer (GRS) method using a Marinelli beaker and the liquid scintillation counter (LSC) method for groundwater. The recovered 226Ra, which was filtered by the solid phase extraction disk, was analyzed using gamma ray spectrometer The disks, which were pretreated for caulking the daughter nuclide, were sealed with polyethylene film. Distilled water was used for the blank value of the 226Ra activity. The recovery values of 214Bi and 214Pb in the solid phase extraction disk, which used 226Ra standard material, were 80% (295.21 Kev) and 104% (351.92 Kev), respectively, which were higher than 75% determined by the LSC. The injection of nitrogen gas into the measuring chamber reduced the interference values by about 10%. The detection limits of the 226Ra activity in a blank sample of 5 L were 0.17~0.40 pCi/L after 80,000 seconds of measuring time. The relationship of the 226Ra activity in the solid phase extraction disk method and in the LSC method in seven groundwater samples showed a correlation coefficient value 0.987, which implies the applicability of the solid phase extraction disk method. The results showed that 226Ra activity in groundwater using the solid phase extraction disk method has the following benefits: simple pretreatment, time saving, high recovery values, a low detection limit, and so on. Compared with the LSC method and the GRS method using the Marinelli beaker for the 226Ra analysis, the solid phase extraction disk method could be useful in groundwater samples with low levels of activities of radionuclides because the method is not restricted by the volume of the sample.

Efficiency Test for Surface Protecting Agents for the Chemical Resistance of Concrete Structures Using Sulfur Polymers (Sulfur Polymer를 사용한 콘크리트 구조물용 내화학성 표면보호재의 성능 평가)

  • Lee, Byung-Jae;Lee, Eue-Sung;Chung, Woo-Jung;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.5
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    • pp.1-8
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    • 2014
  • Structures requiring chemical resistance are usually coated with surface protecting agents, but the cost for maintenance and re-construction is incurred due to the low durability. Therefore, in this study, sulfur was polymerized and the performance was examined so that it could be used as the concrete surface protecting agents for structures requiring chemical resistance. The evaluation results indicated that for the spray of the sulfur polymer surface coating agents, the application of the gravity type was appropriate; and for the number of coating times, about 3 cycle spray gave the best results. For the surface condition of the concrete to be coated with the surface protecting agents, outstanding quality was obtained above room temperature ($20{\sim}30^{\circ}C$), and the bond strength increased as the temperature increased. The evaluation results of the strength characteristics depending on the filler content of the surface protecting agents indicated that about 20~40% filler mixing contributed to the strength improvement as it reduced the shrinkage of the sulfur polymer. Also, the mixing of silica showed larger increase in the bond strength than the mixing of fly ash, and the most outstanding bond strength characteristics could be obtained by the mixing of both silica and fly ash. In the case of the chemical resistance, the strength reduction was minimized and outstanding chemical resistance was obtained when the fly ash and silica were substituted by 20%, respectively. The performance evaluation of the chloride ion penetration indicated that for the specimens coated with the sulfur polymer surface protecting agents, the chloride ion penetration resistance increased by 29~48% compared to the specimen without the coating of the surface protecting agent. The examination of the coating condition of the surface protecting agents, compressive strength, bond strength, chemical resistance, and salt damage resistance indicated that in the range of this study, the optimal level was when the silica and fly ash were substituted by 20%, respectively, as the filler for the sulfur polymer.

Comparative Analysis of ViSCa Platform-based Mobile Payment Service with other Cases (스마트카드 가상화(ViSCa) 플랫폼 기반 모바일 결제 서비스 제안 및 타 사례와의 비교분석)

  • Lee, June-Yeop;Lee, Kyoung-Jun
    • Journal of Intelligence and Information Systems
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    • v.20 no.2
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    • pp.163-178
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    • 2014
  • Following research proposes "Virtualization of Smart Cards (ViSCa)" which is a security system that aims to provide a multi-device platform for the deployment of services that require a strong security protocol, both for the access & authentication and execution of its applications and focuses on analyzing Virtualization of Smart Cards (ViSCa) platform-based mobile payment service by comparing with other similar cases. At the present day, the appearance of new ICT, the diffusion of new user devices (such as smartphones, tablet PC, and so on) and the growth of internet penetration rate are creating many world-shaking services yet in the most of these applications' private information has to be shared, which means that security breaches and illegal access to that information are real threats that have to be solved. Also mobile payment service is, one of the innovative services, has same issues which are real threats for users because mobile payment service sometimes requires user identification, an authentication procedure and confidential data sharing. Thus, an extra layer of security is needed in their communication and execution protocols. The Virtualization of Smart Cards (ViSCa), concept is a holistic approach and centralized management for a security system that pursues to provide a ubiquitous multi-device platform for the arrangement of mobile payment services that demand a powerful security protocol, both for the access & authentication and execution of its applications. In this sense, Virtualization of Smart Cards (ViSCa) offers full interoperability and full access from any user device without any loss of security. The concept prevents possible attacks by third parties, guaranteeing the confidentiality of personal data, bank accounts or private financial information. The Virtualization of Smart Cards (ViSCa) concept is split in two different phases: the execution of the user authentication protocol on the user device and the cloud architecture that executes the secure application. Thus, the secure service access is guaranteed at anytime, anywhere and through any device supporting previously required security mechanisms. The security level is improved by using virtualization technology in the cloud. This virtualization technology is used terminal virtualization to virtualize smart card hardware and thrive to manage virtualized smart cards as a whole, through mobile cloud technology in Virtualization of Smart Cards (ViSCa) platform-based mobile payment service. This entire process is referred to as Smart Card as a Service (SCaaS). Virtualization of Smart Cards (ViSCa) platform-based mobile payment service virtualizes smart card, which is used as payment mean, and loads it in to the mobile cloud. Authentication takes place through application and helps log on to mobile cloud and chooses one of virtualized smart card as a payment method. To decide the scope of the research, which is comparing Virtualization of Smart Cards (ViSCa) platform-based mobile payment service with other similar cases, we categorized the prior researches' mobile payment service groups into distinct feature and service type. Both groups store credit card's data in the mobile device and settle the payment process at the offline market. By the location where the electronic financial transaction information (data) is stored, the groups can be categorized into two main service types. First is "App Method" which loads the data in the server connected to the application. Second "Mobile Card Method" stores its data in the Integrated Circuit (IC) chip, which holds financial transaction data, which is inbuilt in the mobile device secure element (SE). Through prior researches on accept factors of mobile payment service and its market environment, we came up with six key factors of comparative analysis which are economic, generality, security, convenience(ease of use), applicability and efficiency. Within the chosen group, we compared and analyzed the selected cases and Virtualization of Smart Cards (ViSCa) platform-based mobile payment service.

A Study of the Effect of Port Characteristics on the Growth of Port Cities -Based on Pyeongtaek and Gwangyang Ports- (항만입지특성이 항만도시성장에 미치는 영향에 관한 연구 -평택항과 광양항을 중심으로-)

  • Lee, Jeoungho;Choi, Byungdae
    • Journal of Korea Port Economic Association
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    • v.30 no.3
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    • pp.163-185
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    • 2014
  • The growth of a city requires substantial resources, an appropriate environment, and the alignment of several factors. City growth also evolves through changes in its history, culture, economics, societies, groups, and government systems. However, current port city development plans designed to encourage the growth of local businesses fail to provide the support needed for both the city and businesses. The recent actions of urban administrations and federal and local governments have revealed that they have yet to create a mature decentralized management system, or perhaps have ignored the reality of needing one. Taking a clear look at the differences between port regions, such as Gwangyang and Pyeongtaek, and understanding their effect on city growth would be a prudent course of action when preparing for future developments. The purpose of this study is to determine the relationship between ports and cities by analyzing the effect of port characteristics on nearby city growth. This study used a comparison analysis to determine how port characteristics affected the growth of Pyeongtaek and Gwangyang. One result of this analysis showed that an increase in the number of goods being imported or exported had a positive effect on the growth of both port cities, In this respect, an aggressive plan and cooperation between the federal and local government should occur simultaneously. Furthermore, efficient local policies that focus on the increase of personnel and material resources should be pursued as a standard strategy, which would also promote the international status of these locations. The results of this study show the importance of government cooperation. The federal government should lead with aggressive strategies that aim to optimize efficiency, while the local government should provide the necessary assistance and coordination in order to achieve optimal results.

Influence of Water Temperature, Background Color, and Light Intensity in Feeding, Growth and Blind-Side Hypermelanosis of Starry Flounder, Platichthys stellatus (강도다리, Platichthys stellatus의 먹이섭식, 성장 및 무안측 체색발현에 있어 수온, 수조색상 및 조도의 영향)

  • Kang, Duk-Young;Kim, Won-Jin;Kim, Hyo-Chan;Chang, Young Jin
    • Korean Journal of Ichthyology
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    • v.26 no.3
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    • pp.185-193
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    • 2014
  • To find the influence of water temperature, tank color and illumination in feeding, growth and blind-side hypermelanosis of starry flounder, Platichthys stellatus, in the present study, we performed a series of temperature, background color and illumination intensity test for 180 days (From June to December). The test was done in duplicate at 100 fish/tank (430% of initial covering area [PCA]) with the selected ordinary juvenile flounder (TL $17.3{\pm}0.5cm$, BW $82.5{\pm}0.2g$). The rearing was performed in darkgreen FRP aquarium tanks ($H100cm{\times}L100cm{\times}W100cm$; bottom area $1m^2$) lighten with average 1,000 lux and 230 lux, and in white FRP aquarium tank ($H100cm{\times}L100cm{\times}W100cm$; bottom area $1m^2$) lighten with average 230 lux of light intensity. We investigated correlation of daily food intake (DFI) with water temperature and salinity, and compared the influences of background colors and light intensity in DFI, food efficiency (FE), growth, survival rate, and ratio of malpigmented blind-side area and ambicolored fish ratio. In DFI, although it was not related with salinity, the amount was significantly decreased under 0.5 g/fish/day in summer and winter season, but was significantly increased over 1.5 g/fish/day in autumn season showing from $10^{\circ}C$ to $20^{\circ}C$ in water temperature. In background and illumination test, DFI, FE and survival rate showed no difference among three groups. The ratios of malpigmented blind-side area and ambicolored fish were also not significantly different among three groups, indicating that the blind-side hypermelanosis of starry may be governed not by background color (or light intensity) but by a genetics external trait inherited from parents.

Effect of Automatic Exposure Control Marker with Chest Radiography in Radiation Reduction (자동노출제어를 사용한 X선 흉부촬영에서 AEC 표지자 사용에 따른 환자 피폭선량 감소 효과)

  • Jung, Ji-Sang;Choi, Byoung-Wook;Kim, Sung-Ho;Kim, Young-Mo;Shim, Ji-Na;Ahn, Ho-Sik;Jin, Duk-Eun;Lim, Jae-Sik;Kang, Sung-Ho
    • Journal of radiological science and technology
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    • v.37 no.3
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    • pp.177-185
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    • 2014
  • This study focused on effects of patient exposure dose reduction with AEC (Auto Exposure Control) marker that is designed for showing location of AEC in X-ray Chest radiography. It included 880 adults who have to use Chest X-ray Digital Radiography system (DRS, LISTEM, Korea). AEC (Ion chambers are posited in top of both sides) are used to every adult and set X-ray system as Field size $17{\times}17inch$, 120kVp, FFD 180cm. 440 people of control group are posited on detector to include both sides of lung field and the other 440 people of experimental group are set to contact their lung directly to Ion chamber (making marker to shows location). Then, measured every DAP and, estimated patient effective dose by using PCXMC 2.0. The average age of control group (M:F=245:195) is 53.9 and the average BMI is 23.4. BMI ranges from under weight: 35, normal range: 279, over weight: 106 to obese: 20 and average DAP is 223.56mGycm2, Mean effective dose is 0.045mSv. The average age of experimental group (M:F=197:243) is 53.7 and the average BMI is 22.7. BMI ranges from under weight: 34, normal range: 315, over weight: 85 to obese: 6 and average DAP is 207.36mGycm2, Mean effective dose is 0.041mSv. Experimental group shows less Mean effective dose as 0.004mSv (9.7%) than control group. Also, patient numbers who got over exposure more than 0.056mSv (limit point to know efficiency of AEC marker) is 65 in control group (14.7%), 19 in experimental group (4.3%) and take statistics with t-Test. The statistical difference between two groups is 0.006. In order to use proper amount of X-ray in auto exposure controlled chest X-ray system, matching location between ion chamber and body part is needed, and using AEC marker (designed for showing location of ion chamber) is a way to reduce unnecessary patient exposure dose.

An Empirical Study on the Influencing Factors of Perceived Job Performance in the Context of Enterprise Mobile Applications (업무성과에 영향을 주는 업무용 모바일 어플리케이션의 주요 요인에 관한 연구)

  • Chung, Sunghun;Kim, Kimin
    • Asia pacific journal of information systems
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    • v.24 no.1
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    • pp.31-50
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    • 2014
  • The ubiquitous accessibility of information through mobile devices has led to an increased mobility of workers from their fixed workplaces. Market researchers estimate that by 2016, 350 million workers will be using their smartphones for business purposes, and the use of smartphones will offer new business benefits. Enterprises are now adopting mobile technologies for numerous applications to increase their operational efficiency, improve their responsiveness and competitiveness, and cultivate their innovativeness. For these reasons, various organizational aspects concerning "mobile work" have received a great deal of recent attention. Moreover, many CIOs plan to allocate a considerable amount of their budgets mobile work environments. In particular, with the consumerization of information technology, enterprise mobile applications (EMA) have played a significant role in the explosive growth of mobile computing in the workplace, and even in improving sales for firms in this field. EMA can be defined as mobile technologies and role-based applications, as companies design them for specific roles and functions in organizations. Technically, EMA can be defined as business enterprise systems, including critical business functions that enable users to access enterprise systems via wireless mobile devices, such as smartphones or tablets. Specifically, EMA enables employees to have greater access to real-time information, and provides them with simple features and functionalities that are easy for them to complete specific tasks. While the impact of EMA on organizational workers' productivity has been given considerable attention in various literatures, relatively little research effort has been made to examine how EMA actually lead to users' job performance. In particular, we have a limited understanding of what the key antecedents are of such an EMA usage outcome. In this paper, we focus on employees' perceived job performance as the outcome of EMA use, which indicates the successful role of EMA with regard to employees' tasks. Thus, to develop a deeper understanding of the relationship among EMA, its environment, and employees' perceived job performance, we develop a comprehensive model that considers the perceived-fit between EMA and employees' tasks, satisfaction on EMA, and the organizational environment. With this model, we try to examine EMA to explain how job performance through EMA is revealed from both the task-technology fit for EMA and satisfaction on EMA, while also considering the antecedent factors for these constructs. The objectives of this study are to address the following research questions: (1) How can employees successfully manage EMA in order to enhance their perceived job performance? (2) What internal and/or external factors are important antecedents in increasing EMA users' satisfaction on MES and task-technology fit for EMA? (3) What are the impacts of organizational (e.g. organizational agility), and task-related antecedents (e.g., task mobility) on task-technology fit for EMA? (4) What are the impacts of internal (e.g., self-efficacy) and external antecedents (e.g., system reputation) for the habitual use of EMA? Based on a survey from 254 actual employees who use EMA in their workplace across industries, our results indicate that task-technology fit for EMA and satisfaction on EMA are positively associated with job performance. We also identify task mobility, organizational agility, and system accessibility that are found to be positively associated with task-technology fit for EMA. Further, we find that external factor, such as the reputation of EMA, and internal factor, such as self-efficacy for EMA that are found to be positively associated with the satisfaction of EMA. The present findings enable researchers and practitioners to understand the role of EMA, which facilitates organizational workers' efficient work processes, as well as the importance of task-technology fit for EMA. Our model provides a new set of antecedents and consequence variables for a TAM involving mobile applications. The research model also provides empirical evidence that EMA are important mobile services that positively influence individuals' performance. Our findings suggest that perceived organizational agility and task mobility do have a significant influence on task-technology fit for EMA usage through positive beliefs about EMA, that self-efficacy and system reputation can also influence individuals' satisfaction on EMA, and that these factors are important contingent factors for the impact of system satisfaction and perceived job performance. Our findings can help managers gauge the impact of EMA in terms of its contribution to job performance. Our results provide an explanation as to why many firms have recently adopted EMA for efficient business processes and productivity support. Our findings additionally suggest that the cognitive fit between task and technology can be an important requirement for the productivity support of EMA. Further, our study findings can help managers in formulating their strategies and building organizational culture that can affect employees perceived job performance. Managers, thus, can tailor their dependence on EMA as high or low, depending on their task's characteristics, to maximize the job performance in the workplace. Overall, this study strengthens our knowledge regarding the impact of mobile applications in organizational contexts, technology acceptance and the role of task characteristics. To conclude, we hope that our research inspires future studies exploring digital productivity in the workplace and/or taking the role of EMA into account for employee job performance.

Effects of Operation Parameters on Pollutants Removal in a Lab-Scale Multi-Layered Soil Filtration System (하천 수질정화를 위한 실험실 규모 다단식 토양여과 시스템에서 오염물질 제거에 미치는 운전인자의 영향)

  • Won, Se-Yeon;Ki, Dong-Won;Yoon, Min-Hyeok;Maeng, Sung-Kyu;Ahn, Kyu-Hong;Park, Joon-Hong;Song, Kyung-Guen
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.2
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    • pp.91-96
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    • 2012
  • In this study we investigated the effects of operational parameters of a multi-layered soil filtration (filter depth, filtration velocity, and continuous/intermittent operation) on removal of pollutants in river water. As filter depth increased removal of all the pollutants (COD, TP, TN, and $NH_4$-N) was increased because the increase in filter depth increased in contact time between media and pollutants. The removal of TP and $NH_4$-N more increased with the increase in filter depth, comparing to the biological COD removal which was performed only in the top layer, since the removal mechanism of TP and $NH_4$-N was physicochemical process occurring throughout the whole layers. However, the reduction in filtration velocity resulted in decrease of removal all the pollutants removal due to shorter retention time. Biological COD removal was more influenced with the reduction in filtration velocity (longer retention time), than the removal of TP and $NH_4$-N. Because biological process was occurred only in the top layer which has relatively shorter retention time, comparing with physicochemical process occurred throughout whole media. Therefore, it is desirable that the operation parameters be controlled toward increasing retention time, in order to achieve efficient pollutants removal. The change in operation mode (continuos vs. intermittent operations) did not provide significant effects on the pollutant treatment efficiency by the multi-layered soil filtration system. Our findings suggest that for stable long-term operation it should be considered keeping conditions for biological activity and accelerating clogging.

Effect of Non Breeding Season on Oocyte Recovery from Superovulated Korean Native Goats (재래산양의 비번식기에 과배란 처리에 의한 난자 회수와 단위발생란의 체외발달)

  • Yun, Yun Jin;Park, Hee Sung
    • Journal of Embryo Transfer
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    • v.28 no.1
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    • pp.19-24
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    • 2013
  • This study assesses of efficiency of oocyte recovery and in vitro development for during the non breeding season in goat. Thirty-four matured goats, maintained in a pen under natural day length and fed hay ad libitum, were pretreated with progestagen implanted CIDR for 10 days. Superovulation treatment of the goats received twice daily intramuscular injections of a total of 70 mg FSH for 3 days from Day 8 of CIDR. All the gonadotropin treated goats were injected with 10 mg $PGF_2{\alpha}$ on Day 8 and 400~600 IU hCG in the afternoon on Day 10. Oocytes were recovered by follicle aspiration or oviduct flushing at 35 to 40 h after hCG injection through mid-ventral incision. The in vivo matured oocytes were activated by ionomycin (5 min) and 6-DMAP (3.5~4 h). The activated oocytes were cultured in mSOF medium containing 0.8% BSA at $38.5^{\circ}C$ in an atmosphere of 5% $CO_2$, 5% $O_2$, 90% $N_2$ for 7~8 days. There was no significant difference in the mean number of CL and in vivo matured and follicular oocytes recovered. But, quality of I+II grade follicular oocytes was lower (p<0.05) in the prepubertal goat (25.0%) than the adults (52.4%). The same results were also observed in the cleavage and blastocyst rate of activated oocytes. The clavage and blastocyst rate from prepubertal derived oocytes were lower (p<0.05) in the prepubertal goat (54.5%, 23.3%) than the adult goat (86.8%, 46.6%). Considering overall these results, we suggest that maturation of donor goats is a major factor affecting recovered oocytes quality and in vitro development of activated goat oocytes. There was no significant difference in oocyte quality between seasonal treatments.

Effect of Body Condition Score (BCS) on In Vivo Embryo Production and Pregnancy Rate Following Superovulation in Hanwoo (한우에서 신체충실지수(BCS)가 다배란 처리 시 체내 수정란 생산과 수태율에 미치는 영향)

  • Yeom, Gyu-Tae;Park, Hae-Geum;Kim, Nam-Tae;Kim, Sung-Woo;Kim, Hyun;Do, Yoon-Jung;Kim, Young-Sin;Park, Soo-Bong;Kim, Jae-Hwan;Cho, Sang-Rae;Cho, Jae-Hyeon;Ko, Yeoung-Gyu
    • Journal of Embryo Transfer
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    • v.28 no.1
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    • pp.7-12
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    • 2013
  • Body condition score (BCS) is a useful management tool for distinguishing differences in nutritional needs of cows in the herd. Although it is not always possible to quantify the nutrient content of the feed supplied to the donor cow, the nutritional status can be determined by the BCS. The objective of this study was to evaluate in vivo embryo production, return to estrous of donor and pregnancy rate of recipients following BCS in Hanwoo superovulation. Sixty nine Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with Embryo Collection Medium. The results obtained were as follows: No differences were observed in the efficiency of superovulation rates regardless of BCS ($${\leq_-}2.0$$, 2.5 to 3.0, and $${\geq_-}3.5$$). The mean number of total embryos was each $5.20{\pm}0.86$, $11.56{\pm}1.04$, and $6.23{\pm}1.07$. The mean number of transferable embryo from $${\leq_-}2.0$$, 2.5 to 3.0, and $${\geq_-}3.5$$ of BCS was $2.60{\pm}0.87$, $7.94{\pm}0.89$, and $4.75{\pm}1.32$, respectively (p<0.05). Return to estrous regardless of donor BCS was no difference. The pregnancy rates of recipient were BCS $${\leq_-}2.0$$ 11.76%, 2.5 to 3.0 40.79%, and $${\geq_-}3.5$$ 11.11%, following transfer of fresh embryos produced in vivo, respectively. These results indicate that if the Hanwoo with BCS 2.5 to 3.3 are used for donor and recipient, the embryo production and the conception rate will be greater.