• Title/Summary/Keyword: computer-based assessment

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Preliminary Study on the MR Temperature Mapping using Center Array-Sequencing Phase Unwrapping Algorithm (Center Array-Sequencing 위상펼침 기법의 MR 온도영상 적용에 관한 기초연구)

  • Tan, Kee Chin;Kim, Tae-Hyung;Chun, Song-I;Han, Yong-Hee;Choi, Ki-Seung;Lee, Kwang-Sig;Jun, Jae-Ryang;Eun, Choong-Ki;Mun, Chi-Woong
    • Investigative Magnetic Resonance Imaging
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    • v.12 no.2
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    • pp.131-141
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    • 2008
  • Purpose : To investigate the feasibility and accuracy of Proton Resonance Frequency (PRF) shift based magnetic resonance (MR) temperature mapping utilizing the self-developed center array-sequencing phase unwrapping (PU) method for non-invasive temperature monitoring. Materials and Methods : The computer simulation was done on the PU algorithm for performance evaluation before further application to MR thermometry. The MR experiments were conducted in two approaches namely PU experiment, and temperature mapping experiment based on the PU technique with all the image postprocessing implemented in MATLAB. A 1.5T MR scanner employing a knee coil with $T2^*$ GRE (Gradient Recalled Echo) pulse sequence were used throughout the experiments. Various subjects such as water phantom, orange, and agarose gel phantom were used for the assessment of the self-developed PU algorithm. The MR temperature mapping experiment was initially attempted on the agarose gel phantom only with the application of a custom-made thermoregulating water pump as the heating source. Heat was generated to the phantom via hot water circulation whilst temperature variation was observed with T-type thermocouple. The PU program was implemented on the reconstructed wrapped phase images prior to map the temperature distribution of subjects. As the temperature change is directly proportional to the phase difference map, the absolute temperature could be estimated from the summation of the computed temperature difference with the measured ambient temperature of subjects. Results : The PU technique successfully recovered and removed the phase wrapping artifacts on MR phase images with various subjects by producing a smooth and continuous phase map thus producing a more reliable temperature map. Conclusion : This work presented a rapid, and robust self-developed center array-sequencing PU algorithm feasible for the application of MR temperature mapping according to the PRF phase shift property.

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A Study for the Methodology of Analyzing the Operation Behavior of Thermal Energy Grids with Connecting Operation (열 에너지 그리드 연계운전의 운전 거동 특성 분석을 위한 방법론에 관한 연구)

  • Im, Yong Hoon;Lee, Jae Yong;Chung, Mo
    • KIPS Transactions on Computer and Communication Systems
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    • v.1 no.3
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    • pp.143-150
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    • 2012
  • A simulation methodology and corresponding program based on it is to be discussed for analyzing the effects of the networking operation of existing DHC system in connection with CHP system on-site. The practical simulation for arbitrary areas with various building compositions is carried out for the analysis of operational features in both systems, and the various aspects of thermal energy grids with connecting operation are highlighted through the detailed assessment of predicted results. The intrinsic operational features of CHP prime movers, gas engine, gas turbine etc., are effectively implemented by realizing the performance data, i.e. actual operation efficiency in the full and part loads range. For the sake of simplicity, a simple mathematical correlation model is proposed for simulating various aspects of change effectively on the existing DHC system side due to the connecting operation, instead of performing cycle simulations separately. The empirical correlations are developed using the hourly based annual operation data for a branch of the Korean District Heating Corporation (KDHC) and are implicit in relation between main operation parameters such as fuel consumption by use, heat and power production. In the simulation, a variety of system configurations are able to be considered according to any combination of the probable CHP prime-movers, absorption or turbo type cooling chillers of every kind and capacity. From the analysis of the thermal network operation simulations, it is found that the newly proposed methodology of mathematical correlation for modelling of the existing DHC system functions effectively in reflecting the operational variations due to thermal energy grids with connecting operation. The effects of intrinsic features of CHP prime-movers, e.g. the different ratio of heat and power production, various combinations of different types of chillers (i.e. absorption and turbo types) on the overall system operation are discussed in detail with the consideration of operation schemes and corresponding simulation algorithms.

An Evaluation on the Operating of Fisheries Extension Services (어촌지도사업의 평가)

  • 최정윤
    • The Journal of Fisheries Business Administration
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    • v.17 no.2
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    • pp.65-106
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    • 1986
  • 1, The Purpose of Study This is a study on the Evaluation of the operating of Fisheries Extension Services of Korea, for performing the activities such as guiding fisheries technique as well as offering industrial information to the fishermen in fishing village. By doing so, the Fisheries Extension Sevices(FES) can materialize the continued growth of fisheries, the social and economic development of fishing village, and the increase in income by enhancing the knowledge level of Fishermen, etc. In performing fisheries policy, this activity plays a great role on the research and development activity, and it has become practical since 1976 in Korea. In order to meet immediately with the problem of fisheries technical innovation and rapid environmental changes surrounding the fisheries, the fishermen should not only enhance their scientific and comprehensive capacity in fisheries technique but abtain various effective information. Generally, as most of all the fishemen are poor in the managerial structure and scattered in fishing villages, they have little opportunity in the contact of information. As a result, it is nessessary for the FES to perform the fishing business by the extension service officials who has received special training and acquired fisheries know-how in these fields. And yet, FES is under the unfullfilled circumstance in such factors as manpower, technical know-how, equipment, and the service system etc., which is required in promoting the social, economic development of fishing village and in resolving the high technique demand of fisherman. This study on the fisheries extension services have been studied from those backgrounds. 2. Research Method The data of collecting methods which were necessary in carrying out this study was adopted by the questionaire research on the present extension service activity, through the subject of the extension services (driving agency of the work and the officials), the object(fishemen) and the 3rd observers to the extension services (the authorities concerned). The research sample was taken by the sampling extraction of total 1, 774 men from the above 3 groups. And the research was carried out from August, 1986 to October, 1986, supported from the Fisheries Extension Office (FEO) located in field during the research process. In this study, the levels of the extension operating were determined and estimated in accordance with the extension service method, morale of extension service officials and the extension service system, etc. through the collected data of the research questionaire paper. And based on this result, the essential conditions of the extension services were grasped, and also we tried to present the various activity plan necessary to promote the operating of the extension services. The questionaire research data was calculated by the computer center of National Fisheries University of Pusan, and the total result was again tried on the one demension analysis along with two dimension analysis to search out the relativity between the questionaire, and the statistical test was done $\chi$$^2$test in significance level of l~5%. 3. Contents of Study This study consists of 7 chapters and the contents are as follows : Chapter I : The object and method of the study Chapter II : The assessment and analysis of the extension services Chapter III : The contents and method of the extension services Chapter IV : Analysis of the essential conditions for the extension services Chapter V : The evaluation of activities of extension services Chapter Ⅵ : Conclusion.4. Results and RecommendationTherefore, the results of this study estimated by logical process and analysis are as follows : 1) Most of Korean fishing villages and coastal fishermen have shown much concerns about fisheries technique and social changes, thus many of them were confronted with new problems on how to adapt and to meet changes. 2) Majority of fishermen estimated FEO as an organization of specific technologies with all the thing concerning the fisheries technique in general. Therefore the fishermen wanted to utilize the FEO as an adaptable method for the modern fisheries techniques as well as the environmental changes. 3) In contrast with the fast changes of the fisheries technique, the complexity and variety of technical system and the broadness of fishing village and fishermen, it was revealed that the necessary factors such as the facilities, manpower, budget, and the level of applying techniques of the FEO located in field were highly insufficient. Accordingly, the guiding efficiency was low and the extension services did not provide full solution to the various request from fishermen. 4) It is possible to classify the activation factor for the extension service into two large dimension ; personal dimension relevant to guidance officials and work dimension relevant to the organization. And it was found that the activation level of the work dimension was far lower than the personal dimension between them. So, the activation should be done first in the dimesion to promote the activation of the extension services. 5) The extension services officials are now demoralized in general, thus it is necessary to take reality into consideration : the expense of activity, the adequate endowment of activity scope and the reasonable operation of the position class, etc to enhance its morale. However, in order to do the FES activation, first of all, the systems should be established which is lain unsettled stage until now. And there must be change in the understanding of government i.e. the fisheries extension services are the essential policy subject to build up the base of fisheries growth and modernize the fisheries management. And it should be driven positively with the recognition of the "lasting project".g project".uot;.

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Radiological Dose Analysis to the Public Resulting from the Operation of Daedeok Nuclear Facilities (대덕부지 원자력관련시설 운영에 따른 주민피폭선량 현황분석)

  • Jeong, Hae Sun;Kim, Eun Han;Jeong, Hyo Joon;Han, Moon Hee;Park, Mi Sun;Hwang, Won Tae
    • Journal of Radiation Protection and Research
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    • v.39 no.1
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    • pp.38-45
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    • 2014
  • This paper describes the results of assessment of radiological dose resulting from operation of the Daedeok nuclear facilities including the HANARO research reactor, which has been performed to assure whether or not to comply with the regulation standards of the radioactive effluents releases. Based on the meteorological data and the radiation source term, the maximum individual doses were evaluated from 2010 to 2012. The atmospheric dispersion and the deposition factors of gaseous effluents were calculated using the XOQDOQ computer code. ENDOS-G and ENDOS-L code systems were also used for maximum individual dose calculation from gaseous and liquid effluents, respectively. The results were compared with the regulation standards for the radioactive effluents presented by the Nuclear Safety and Security Commission (NSSC). The effective doses and the thyroid doses of the maximum individual were calculated at the maximum exposed point in the Daedeok site, and contributions of exposure pathways to the radiological doses resulting from gaseous and liquid radioactive effluents were evaluated at each facility of the Daedeok site. As a result, the maximum exposed age was analysed to be the child group, and the operation of HANARO research reactor had a major effect more than 90% on the individual doses. The main exposure pathways for gaseous radioactive effluent were from ingestion and inhalation. The effective doses and the thyroid doses were considerably influenced by tritium and iodine, respectively. The gaseous radioactive effluents contributed more than 90% on the total doses, whereas the contributions of the liquid radioactive effluents were relatively low. Consequently, the maximum individual dose due to radioactive effluents from the nuclear facilities within the Daedeok site were less than 3% of the regulation standard over 3 years; therefore, it can be concluded that radioactive effluents from the nuclear facilities were well managed, with the radiation-induced health detriment for residents around the site being negligible.

Assessment of modifiable lifestyle factors for obese children and adolescents through questionnaires (소아청소년 비만상담에서 설문지를 이용한 중재 가능한 행동요인 탐색)

  • Seo, Jeong Wan;Jung, Ji A;Park, Hye Sook;Ko, Jae Sung;Kim, Yong Joo;Kim, Jae Young;Ryoo, Eell;Bae, Sun Hwan;Sim, Jae Geon;Yang, Hye Ran;Choe, Byung Ho;Cho, Ky Young
    • Clinical and Experimental Pediatrics
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    • v.51 no.6
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    • pp.576-583
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    • 2008
  • Purpose : The identification of specific behaviors conducive to overeating or inactivity is the cornerstone of obesity management. The Committee on Nutrition of the Korean Pediatric Society developed parent and self-reporting questionnaires about eating behavior and physical activity in 2006. The aim of this study was to evaluate the usefulness of the questionnaires in assessing modifiable lifestyle factors related to obesity. Methods : A retrospective chart review was performed for 177 children (6-11 years old) and 134 adolescents (12-16 years old) from 10 hospitals between May 2006 and January 2007 who had completed parent or self-reporting questionnaires. Cases were divided into normal and overweight groups at or above the age-gender-specific 85th percentile based on 2007 Korean national growth charts. Results : Compared to children, the adolescents tended to have a significantly more sedentary lifestvle and inappropriate dietary behaviors significantly (P<.05). Overweight mothers were significantly associated with overweight children and adolescents (P<.05). Being overweight was significantly associated with a family history of adult diseases for children and adolescents (P<.05). Inappropriate eating behaviors (strong appetite, eating fast, eating until they were full, binge eating, favoring greasy foods) were associated with being overweight in children and adolescents. Sedentary activity such as TV viewing and using a computer were significantly associated with overweight in children and adolescents (P<.05). Conclusion : Intervention to modify obesity-related lifestyle factors is needed before adolescence. These questionnaires are useful in identifying modifiable lifestyle factors and in individual counseling for overweight children and adolescents in pediatric clinics.

Considerations for Helping Korean Students Write Better Technical Papers in English (한국 대학생들의 영어 기술 논문 작성 능력 향상을 위한 고찰)

  • Kim, Yee-Jin;Pak, Bo-Young;Lee, Chang-Ha;Kim, Moon-Kyum
    • Journal of Engineering Education Research
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    • v.10 no.3
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    • pp.64-78
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    • 2007
  • For Korean researchers, English is essential. In fact, this is the case for any researcher who is a non-native English speaker, as recognition and success is predicated on being published, while publications that reach the broadest audiences are in English. Unfortunately, university science and engineering programs in Korea often do not provide formal coursework to help students attain greater competence in English composition. Aggravating this situation is the general lack of literature covering this specific pedagogical issue. While there is plenty of information to help native speakers with technical writing and much covering general English composition for EFL learners, there is very little information available to help EFL learners become better technical writers. Thus, the purpose of this report is twofold. First, as most Korean educators in science and engineering are not well acquainted with pedagogical issues of EFL writing, this report provides a general introduction to some relevant issues. It reviews the importance of contrastive rhetoric as well as some considerations for choosing the appropriate teaching approach, class arrangement, and use of computer assisted learning tools. Secondly, a course proposal is discussed. Based on a review of student writing samples as well as student responses to a self-assessment questionnaire, the proposed course is intended to balance the needs of Korean EFL learners to develop grammar, process, and genre skills involved in technical writing. Although, the scope of this report is very modest, by sharing the considerations made towards the development of an EFL technical writing course it seeks to provide a small example to a field that is perhaps lacking examples.

Electronic Word-of-Mouth in B2C Virtual Communities: An Empirical Study from CTrip.com (B2C허의사구중적전자구비(B2C虚拟社区中的电子口碑): 관우휴정려유망적실증연구(关于携程旅游网的实证研究))

  • Li, Guoxin;Elliot, Statia;Choi, Chris
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.3
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    • pp.262-268
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    • 2010
  • Virtual communities (VCs) have developed rapidly, with more and more people participating in them to exchange information and opinions. A virtual community is a group of people who may or may not meet one another face to face, and who exchange words and ideas through the mediation of computer bulletin boards and networks. A business-to-consumer virtual community (B2CVC) is a commercial group that creates a trustworthy environment intended to motivate consumers to be more willing to buy from an online store. B2CVCs create a social atmosphere through information contribution such as recommendations, reviews, and ratings of buyers and sellers. Although the importance of B2CVCs has been recognized, few studies have been conducted to examine members' word-of-mouth behavior within these communities. This study proposes a model of involvement, statistics, trust, "stickiness," and word-of-mouth in a B2CVC and explores the relationships among these elements based on empirical data. The objectives are threefold: (i) to empirically test a B2CVC model that integrates measures of beliefs, attitudes, and behaviors; (ii) to better understand the nature of these relationships, specifically through word-of-mouth as a measure of revenue generation; and (iii) to better understand the role of stickiness of B2CVC in CRM marketing. The model incorporates three key elements concerning community members: (i) their beliefs, measured in terms of their involvement assessment; (ii) their attitudes, measured in terms of their satisfaction and trust; and, (iii) their behavior, measured in terms of site stickiness and their word-of-mouth. Involvement is considered the motivation for consumers to participate in a virtual community. For B2CVC members, information searching and posting have been proposed as the main purpose for their involvement. Satisfaction has been reviewed as an important indicator of a member's overall community evaluation, and conceptualized by different levels of member interactions with their VC. The formation and expansion of a VC depends on the willingness of members to share information and services. Researchers have found that trust is a core component facilitating the anonymous interaction in VCs and e-commerce, and therefore trust-building in VCs has been a common research topic. It is clear that the success of a B2CVC depends on the stickiness of its members to enhance purchasing potential. Opinions communicated and information exchanged between members may represent a type of written word-of-mouth. Therefore, word-of-mouth is one of the primary factors driving the diffusion of B2CVCs across the Internet. Figure 1 presents the research model and hypotheses. The model was tested through the implementation of an online survey of CTrip Travel VC members. A total of 243 collected questionnaires was reduced to 204 usable questionnaires through an empirical process of data cleaning. The study's hypotheses examined the extent to which involvement, satisfaction, and trust influence B2CVC stickiness and members' word-of-mouth. Structural Equation Modeling tested the hypotheses in the analysis, and the structural model fit indices were within accepted thresholds: ${\chi}^2^$/df was 2.76, NFI was .904, IFI was .931, CFI was .930, and RMSEA was .017. Results indicated that involvement has a significant influence on satisfaction (p<0.001, ${\beta}$=0.809). The proportion of variance in satisfaction explained by members' involvement was over half (adjusted $R^2$=0.654), reflecting a strong association. The effect of involvement on trust was also statistically significant (p<0.001, ${\beta}$=0.751), with 57 percent of the variance in trust explained by involvement (adjusted $R^2$=0.563). When the construct "stickiness" was treated as a dependent variable, the proportion of variance explained by the variables of trust and satisfaction was relatively low (adjusted $R^2$=0.331). Satisfaction did have a significant influence on stickiness, with ${\beta}$=0.514. However, unexpectedly, the influence of trust was not even significant (p=0.231, t=1.197), rejecting that proposed hypothesis. The importance of stickiness in the model was more significant because of its effect on e-WOM with ${\beta}$=0.920 (p<0.001). Here, the measures of Stickiness explain over eighty of the variance in e-WOM (Adjusted $R^2$=0.846). Overall, the results of the study supported the hypothesized relationships between members' involvement in a B2CVC and their satisfaction with and trust of it. However, trust, as a traditional measure in behavioral models, has no significant influence on stickiness in the B2CVC environment. This study contributes to the growing body of literature on B2CVCs, specifically addressing gaps in the academic research by integrating measures of beliefs, attitudes, and behaviors in one model. The results provide additional insights to behavioral factors in a B2CVC environment, helping to sort out relationships between traditional measures and relatively new measures. For practitioners, the identification of factors, such as member involvement, that strongly influence B2CVC member satisfaction can help focus technological resources in key areas. Global e-marketers can develop marketing strategies directly targeting B2CVC members. In the global tourism business, they can target Chinese members of a B2CVC by providing special discounts for active community members or developing early adopter programs to encourage stickiness in the community. Future studies are called for, and more sophisticated modeling, to expand the measurement of B2CVC member behavior and to conduct experiments across industries, communities, and cultures.