• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.143-151
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• 2003

A series of fishing experiments was carried out in the waters off the east coast of Korea from January, 2002 to March, 2003, using gill nets of different mesh sizes (m = 180, 210, 240, 270, and 300 ㎜) to determine the size selectivity of gill net for male snow crab Chionoecetes opilio. The maximum carapace length (RL) of each male snow crab caught in the fishing experiment was measured. The master curve of mesh selectivity was estimated by applying the extended Kitahara's method. Two kinds of functional models, quadratic function and cubic function were used to express logarithmic selectivity curve and were fitted to the data using the method of least squares. The obtained results were summarized as follows; 1. The cubic function of asymmetry was chosen to determine the selectivity curve of gill net for male snow crab from the model deviance comparison. 2. The result of size selectivity showed that the catch number of small male crab was getting decreased according to the increase of mesh size. 3. The optimum value (RL/m) was 0.549 and the RL/m was estimated to be 0.281, 0.296, and 0.356 when the retention probability were 0.2, 0.25 and 0.5, respectively.

• Environmental and Resource Economics Review
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• v.25 no.1
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• pp.1-25
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• 2016

This study investigated the variability of WTP estimates(i.e. mean or median) with ad hoc assumptions of specific parametric probability distributions(i.e. normal, logistic, lognormal, and exponential distribution) to estimate WTP function using dichotomous choice CV data on mortality risk reduction. From the perspective of policy decision, the variability of these WTP estimates are intolerable in comparison with those of Turnbull nonparametric estimation method which is free from ad hoc distribution assumptions. The Turnbull nonparametric estimation can avoid a kind of misspecification bias due to ad hoc assumption of specific parametric distributions. Furthermore, the WTP estimates by Turnbull nonparametric estimation are robust because the similar estimates are elicited from a dichotomous choice or double dichotomous choice CV data, and the statistically significant WTP estimates can be obtained even though it is not possible by parametric estimation methods. If there are considerable variability among those WTP estimates by parametric estimation methods in condition with no criteria of model adequacy, the mean WTPs from Turnbull nonparametric estimation can be the robust estimates without ad hoc assumptions, which can avoid controversial issues in the perspective of policy decisions.

• Journal of Educational Research in Mathematics
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• v.23 no.3
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• pp.335-351
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• 2013

This research assumes that abduction is so important as much as all the creative plausible reasoning to be based upon. We expect it to be deeply appreciated and be taught positively in school mathematics. We are noticing that every problem solving process must contain some steps of abduction and thus, we believe that those who are afraid of abduction cannot solve any newly faced problem. Upon these thoughts, we are looking into the middle school mathematics textbooks to see that how strongly various abductions are emphasized to solve problems in it. We modified types of abduction those were suggested by Eco(1983) or by Bettina Pedemonte, David Reid (2011) and investigated those books to see if, we may regard, various types of abduction be intended to be used to solve their problems. As a result of it, we found that more than 92% of the problems were not supposed to use creative abduction necessarily to solve it. And we interpret this as most authors of the textbooks have emphasis more on the capturing and understanding of basic knowledge of school mathematics rather than the creative reasoning through them. And we believe this need innovation, otherwise strong debates are necessary among the professionals of it.

• The Korean Journal of Financial Studies
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• v.3 no.2
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• pp.51-66
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• 1996

금융가격별 지표의 변동성 증가에 대처하려는 보수적 투자가들이 이용할 수 있는 매력적 방안의 하나가 보험부 투자기법이다. 그러나 이 투자유형은 설계에 상당한 신축성을 보이며 이는 동시에 투자성과 구조의 신축성으로 반영된다. 주요한 설계차원의 하나가 위험투자의 손실발생시 보상차원이다. 여기에 일반적 보험개념을 적용할 때 투자가가 직면하는 선택문제의 하나는 부분보험계약형 투자설계시 공제부보험형 전략과 공동보험형 전략간의 선택이다. 일반적 보험 이론에서는 전자가 후자에 대해 우월한 유형이라는 것이 밝혀져 있다. 본 연구는 이를 보험부투자에 응용할 때도 양 전략간에 어떠한 우월관계가 존재하는 지 알아보려 시도했다. 이를 위해 효율성 평가기준의 하나인 간편한 확률적 지배기준을 적용하였으며 분석결과는 생산적이었다. 두 전략 각각의 기대수익률의 확률분포를 대상으로 기대수익률이 상대적으로 공제부보험형 전략에서 공동보험형 전략에서보다 상대적으로 높거나 최소한 같은 경우에 전자가 후자를 지배하며 그 반대조건인 경우에는 양 전략간에 우열관계가 나타나지 않는다는 결과를 얻었다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.475-477
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• 2004

이동전화 가입자 수의 폭발적 증가와 전송속도 향상으로 고성능 이동전화인 스마트폰이 주목을 받고 있으며, 스마트폰상에서 작동하는 지능형 서비스의 필요성이 커지고 있다. 본 논문에서는 스마트폰에서 지능형 서비스를 구현하는 방법으로 지능형 캐릭터를 제안한다. 캐릭터는 사용자가 친숙하게 느낄 수 있어 지능형 서비스의 좋은 인터페이스가 될 수 있다. 제안하는 캐릭터는 베이지안 네트워크를 이용하여 추론된 사용자의 감정 상태, 바쁨의 정보 등의 정보와 스마트폰에서 수집된 디바이스 상태에 기반하여 행동 선택을 행동 선택을 하여 디바이스와 사용자의 상태를 반영한다. 실제 작동 예를 통해 제안하는 캐릭터의 유용성을 보인다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.217-228
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• 2011

In centralize CDN systems, the content server selection is performed by service node for every user request, and the selected node is notified to the user. In this paper, we present distributed CDN architecture and algorithm in which the request from a user is delivered to the content source by a P2P algorithm utilizing DHT(distributed hash table) through the overlay network and the user selects one of the source nodes based on real-time user-centric criteria. For this purpose, we propose a modified Pastry algorithm for contents registration, search and selection, in addition to the distributed architecture. The proposed architecture has the advantages of load balancing, traffic balancing, scalability, fault-tolerance due to the self-configuration, self-healing attributes of distributed architecture. Various simulation shows the feasibility of the proposed architecture and algorithm, and the performance is compared and discussed for the variations of the proposed scheme.

• School Mathematics
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• v.13 no.1
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• pp.1-17
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• 2011

This study investigated the Chinese national university entrance examination (Gaokao) in mathematics administered in 2009 and 2010 to draw out some implications on the College Scholastic Ability Test (CSAT) in mathematics of Korea. To evaluate the attainments of basic mathematical skills and multilateral abilities required for further studies in university, the Gaokao mathematics is set in two forms(Art/Science), based on the Chinese national mathematics curriculum. The types of items in the Gaokao mathematics are multiple-choice, single-answer, and write-out-answer. The mathematical abilities that the Gaokao mathematics evaluates are mathematical reasoning, operation, geometrical imagination, application, and creativity. As a result, some implications on the Korean CSAT are drawn out in terms of the level of difficulty, the types of items, the arrangements, and the scores of items.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.831-843
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• 2009

In this paper, we propose a new adaptive cooperation scheme with multi-relay nodes which achieves higher performance and spectral efficiency than that of some conventional cooperative schemes. The relay-selection is applied to choose the most potential relay among K ones. Afterward, the instantaneous signal-to-noise ratio (SNR) differences between S-D, S-R and R-D channels are considered for adaptive selection between the direct and the cooperation transmission strategy. In the proposed adaptive protocol, if the direct link is of high quality, the source will transmit to destination directly with all power consumption. Otherwise, the source broadcasts the signal with a lower power and requires the help of the chosen relay if it decodes correctly, else the source will transmit again with remaining power. Firstly, the spectral efficiency is derived by calculating the probability of each mode. Subsequently, the BER performance for the adaptive cooperation scheme is analyzed by considering each event that one of K relays is selected and then making the summation of all. Finally, the numerical results are presented to confirm the performance enhancement offered by the proposed schemes.

• Journal of Educational Research in Mathematics
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• v.23 no.2
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• pp.193-212
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• 2013

This paper aims to identify factors to elevate the effectiveness of a high school mathematics teacher's training program focused on the construction of test items, and to make a blueprint for the training program development of high school mathematics teachers. This study created and executed a teacher's training program, and then twice applied focus group interviews with the teachers who participated in the program. As a result, this study identifies four factors that elevate the effectiveness of a high school mathematics teacher's training program focused on the construction of test items: the structure of the training program that allows teachers to concentrate on constructing test items, the recognition and revision of their habits related to the construction of test items, the formation of a consensus among the participants, and self-reflection on the teachers' specialties in the construction of the test items.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.339-346
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• 2021

In this paper, we implemented an interface that provides a better food ordering mechanism and enables real-time selection of recipe ingredient ratios for customized food orders from global customers. Providing appropriate food to global customers by arranging a selection of menu on the order system screen that shows the basic ratio of each recipe ingredient and provides a customized recipe ingredient composition ratio by configuring a recipe graph without a system for simply selecting and ordering food menus. By enabling interaction, it allows users to provide customized services through the ratio adjustment of various recipe ingredients in the food menu ordering device