• Communications for Statistical Applications and Methods
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• 제27권6호
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• pp.625-639
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• 2020

The gamma distribution is a flexible right-skewed distribution widely used in many areas, and it is of great interest to estimate the probability of a random variable exceeding a specified value in survival and reliability analysis. Therefore, the study develops a fixed-accuracy confidence interval for P(X > c) when X follows a gamma distribution, Γ(α, β), and c is a preassigned positive constant through: 1) a purely sequential procedure with known shape parameter α and unknown rate parameter β; and 2) a nonparametric purely sequential procedure with both shape and rate parameters unknown. Both procedures enjoy appealing asymptotic first-order efficiency and asymptotic consistency properties. Extensive simulations validate the theoretical findings. Three real-life data examples from health studies and steel manufacturing study are discussed to illustrate the practical applicability of both procedures.

• 한국통신학회논문지
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• 제37B권11호
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• pp.1072-1081
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• 2012

Ka 대역 위성통신 시스템에서 강우 감쇠 보상을 위해서는 위성 탑재체에서 강우 지역의 출력 전력을 높일 수 있는 시스템이 요구된다. Ka 대역 출력 전력 제어 기술은 위성 탑재체에서 하향 링크(19.8 ~ 22.2 GHz)의 출력 전력 조정을 가능하게 한다. 본 논문에서는 다중 빔 안테나와 다중 입출력 증폭기를 이용한 Ka 대역 위성 출력전력 제어 기술에 대하여 소개한다. 한반도 상에 8개의 빔을 형성하기 위해 배열 급전 소자와 반사판으로 구성된 다중 빔 안테나가 설계되었다. 빔 당 목표 EIRP는 59 dBW 이상이며, 강우 감쇠 보상을 위한 전력 제어 기능은 강우 지역에 비 강우 지역 대비 최대 6 dB의 EIRP 상승이 가능하도록 설계하였다. 다중 입출력 증폭기는 다중 빔 안테나와 함께 구성될 때 위성 출력 전력 제어를 위해 효과적으로 사용될 수 있다. $4{\times}4$ 다중 입출력 증폭기가 기술 검증을 위해 제작되었으며 Ka 대역 위성 송신 주파수 대역에서 24 dB 이상의 격리도 성능을 나타낸다.

• Journal of Ecology and Environment
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• 제47권4호
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• pp.168-176
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• 2023

Background: Many insectivorous bats have flexible diets, and the difference in prey item consumption among species is one of the key mechanisms that allows for the avoidance of interspecies competition and promotes coexistence within a microhabitat. In Korea, of the 24 bat species that are known to be distributed, eight insectivorous bats use forest areas as both roosting and foraging sites. Here, we aimed to understand the resource partitioning and coexistence strategies between two bat species, Myotis ikonnikovi and Plecotus ognevi, cohabiting the Mt. Jumbong forests, by comparing the differences in dietary consumption based on habitat utilization. Results: Upon examining their dietary composition using the DNA meta-barcoding approach, we identified 403 prey items (amplicon sequence variants). A greater prey diversity including Lepidoptera, Diptera, Coleoptera, and Ephemeroptera, was detected from M. ikonnikovi, whereas most prey items identified from P. ognevi belonged to Lepidoptera. The diversity index of prey items was higher for M. ikonnikovi (H': 5.67, D: 0.995) than that for P. ognevi (H': 4.31, D: 0.985). Pianka's index value was 0.207, indicating little overlap in the dietary composition of these bat species. Our results suggest that M. ikonnikovi has a wider diet composition than P. ognevi. Conclusions: Based on the dietary analysis results, our results suggests the possibility of differences in foraging site preferences or microhabitat utilization between two bat species cohabiting the Mt. Jumbong. In addition, these differences may represent one of the important mechanism in reducing interspecific competition and enabling coexistence between the two bat species. We expected that our results will be valuable for understanding resource partitioning and the coexistence of bats inhabiting the Korean forests.

• 디자인학연구
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• 제19권3호
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• pp.31-44
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• 2006

With 'the improvement of brand image through the consolidation of the online and offline brand images' as the goal, the focus of this study lies in brand color. In order to analyze the differences between the website and offline image of a brand, as felt by the consumers, a survey on color image was conducted. Using the results of the survey as the foundation, a comparative analysis of online and offline color images was conducted, and the discrepancies between the two specified. Furthermore, solutions in creating websites that cultivate brand consolidation through color consolidation are presented. Using the thesis 'Research on the Color Strategy of Brand-name Coffees,' as a guide, and supplementing it with necessary improvements, this study presents three areas to consider when designing or managing websites for offline brands. First of all, color image is not static but variable, meaning that it appeals to the consumers differently, depending on change in other brands, trends, consumer point of view, etc. Thus, color image must be flexible. Secondly, overall brand image can be improved by its offline color. However, it should be realized that identical colors could produce different results online and off. Lastly, in general, the online image falls behind the offline image, in regard to color strategy. Therefore, more meticulous and carefully planned color design is necessary, as is the consideration of the unique and distinctive qualities of the World Wide Web.

• 한국사회복지학
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• 제46권
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• pp.60-88
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• 2001

This paper examined the impacts of the welfare reform program, California Work Pays Demonstration Program(CWPDP), implemented in 1992. CWPDP was designed to move welfare recipients into the labor market by reducing the amount of AFDC grants and one-third earned income disregard. The evaluation of the policy impacts on the welfare recipients was conducted in two areas: employment and earnings. This study used a subset of a database created by the California Department of Social Services, and University of California Data Archive and Technical Assistance. The subset is composed of 3,936 AFDC-FG cases selected in LA County: 1,311 control cases and 2,625 experimental cases. The control group was kept on the AFDC rules as of September 1992, while the experimental group was subject to AFDC rule changes implemented under CWPDP. The analyses of the employment and earnings using the random effects probit model and the random effects regression model, respectively, indicated that CWPDP did not effectively encourage female heads to participate in the labor market. It also revealed that CWPDP did not significantly increase the earnings of female heads. The findings imply that the disincentive structure of the public assistance program is not the main barrier preventing female heads from getting jobs and leaving the welfare rolls. Rather, participation in the labor market and exit from welfare is mainly determined by their own demographic characteristics and the economic cycle. Based on the findings, policy implications are suggested on the National Minimum Protection Program in Korea. Those include a flexible exemption rate for the earned income of beneficiaries, affordable child care services, and guaranteed public jobs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.4103-4117
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• 2014

Image processing and computer vision algorithms are gaining larger concern in a variety of application areas such as robotics and man-machine interaction. Vision allows the development of flexible, intelligent, and less intrusive approaches than most of the other sensor systems. In this work, we determine the location and orientation of a mobile robot which is crucial for performing its tasks. In order to be able to operate in real time there is a need to speed up different vision routines. Therefore, we present and evaluate a method for introducing parallelism into the multiple non-overlapping camera pose estimation algorithm proposed in [1]. In this algorithm the problem has been solved in real time using multiple non-overlapping cameras and the Extended Kalman Filter (EKF). Four cameras arranged in two back-to-back pairs are put on the platform of a moving robot. An important benefit of using multiple cameras for robot pose estimation is the capability of resolving vision uncertainties such as the bas-relief ambiguity. The proposed method is based on algorithmic skeletons for low, medium and high levels of parallelization. The analysis shows that the use of a multiprocessor system enhances the system performance by about 87%. In addition, the proposed design is scalable, which is necaccery in this application where the number of features changes repeatedly.

• Journal of Information Technology Applications and Management
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• 제26권3호
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• pp.1-18
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• 2019

As technology rapidly develops, the demand for manpower by new industries is increasing. In order to respond to the changing demands of the workforce, universities are actively introducing interdisciplinary majors, which is a program formed by two or more departments cooperating to develop new majors. Although the importance of the interdisciplinary major is increasing, universities have difficulties managing them due to non-flexible educational systems. The purpose of this study is to present an effective management direction for interdisciplinary majors based on the results of a survey on student satisfaction with interdisciplinary majors. Also, we analyzed the required level and possessed level of the IS practitioners' competencies, and developed specific educational directions for training IS talents. The results showed that there was a significant difference in satisfaction with the curriculum development and curriculum evaluation of existing subjects provided by existing departments and new subjects established of interdisciplinary majors, specifically the satisfaction of new subjects is higher than existing subjects. In the IS field, there was a high demand for education in the following areas, in order: information security, information technology strategy planning, information technology operation, information technology development, information technology management, information technology sales, and core competencies. Based on the results of the analysis, the satisfaction of students and the cultivation of the talents that the interdisciplinary major aims to develop can be improved.

• 한국임상약학회지
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• 제31권1호
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• pp.1-11
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• 2021

Objective: This study aimed to overview and assess the effectiveness of the policies and regulations that have governed new drug access in Korea, and to propose policies to enhance patient access to drugs, particularly for new innovative medicines. Methods: We approached drug access issues in two perspectives: approval lag (or availability) and reimbursement lag (or affordability). The issues were identified and evaluated through the review of literature, public documents, reports published by the government agencies and private organizations, and news articles. Results: To shorten approval lag, it is recommended to hire and train more reviewers at the Ministry of Food and Drug Safety. Increasing user fees to a realistic level can facilitate this process. To reduce reimbursement lag, flexible incremental cost-effectiveness ratio threshold, alternative cost-effectiveness evaluation, and establishment of funding source other than the national health insurance are identified as the areas to be improved. Conclusion: The current policies and regulations had to be supplemented by new systems to drastically promote patient accessibility to new drugs, consequently in order to promote national public health.

• Architectural research
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• 제25권2호
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• pp.29-40
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• 2023

The purpose of this study is to analyze the conflicts caused by the spatial expansion in two types of urban heritage in Seoul. To explain the national and professional orientation found in each spatial transformation, the study brought the concept of 'historic state' and 'epitome,' thereby examining the operating system of the conflicts. Field observations and stakeholder interviews were performed based on literature and historical research. The study results are as follows. ①In the case of Gwanghwamun and Donuimun, the spatial expansion is to find the historic state of the sites. Gwanghwamun with high national status and substance, conflicts show a pattern that spreads to memory conflicts. Donuimun is relatively unknown and has no substance so that a flexible method of digital restoration was applied. ② In the case of Ikseon-dong and Bukchon hanok, they show heterogeneous spatial expansion. The conflicts in relation to this is caused by the epitome of hanok. In Ikseon-dong, illegal installation of structures(non-epitome) is prevalent, while in Bukchon, there was a process of transferring the new basement(non-epitome) as part of the hanok. ③Conflicts in Gwanghwamun can be coordinated by referring to the digital restoration of Donuimun, and conflicts in Ikseon-dong can be resolved by taking Bukchon as a precedent.

• 한국농공학회지
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• 제44권5호
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• pp.96-105
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• 2002

As an useful water purification system for non-point source pollution in rural watersheds, interests in constructed wetlands are growing at home and abroad. It is well known that constructed wetlands are easily installed, no special managemental needs, and more flexible at fluctuating influent loads. They have a capacity for purification against nutrient materials such as phosphorus and nitrogen causing eutrophication of lentic water bodies. The Constructed Wetland Design Model (CWDM), developed through this study is consisted mainly of Database System, Runoff-discharge Prediction Submodel, Water Quality Prediction Submodel, and Area Assessment Submodel. The Database System includes data of watershed, discharge, water quality, pollution source, and design factors for the constructed wetland. It supplies data when predicting water quality and calculating the required areas of constructed wetlands. For the assessment of design flow, the GWLF (Generalized Watershed Loading Function) is used, and for water quality prediction in streams estimating influent pollutant load, Water Quality Prediction Submodel, that is a submodel of DSS-WQMRA model developed by previous works is amended. The calculation of the required areas of constructed wetlands is achieved using effluent target concentrations and area calculation equations that developed from the monitoring results in the United States. The CWDM is applied to Bokha watershed to appraise its application by assessing design flow and predicting water quality. Its application is performed through two calculations: one is to achieve each target effluent concentrations of BOD, SS, T-N and T-P, the other is to achieve overall target effluent concentrations. To prove the validity of the model, a comparison of unit removal rates between the calculated one from this study and the monitoring result from existing wetlands in Korea, Japan and United States was made. As a result, the CWDM could be very useful design tool for the constructed wetland in rural watersheds and for the non-point source pollution management.