• The KIPS Transactions:PartA
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• v.13A no.5 s.102
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• pp.405-412
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• 2006

Real-time operating systems have been used in various computing environments, where a job must be completed in its deadline, with various conditions, such as effective scheduling policies, the minimum of an interrupt delay, and the solutions of priority inversion problems, that should be perfectly satisfied to design and develop optimal real-time operating systems. Up to now, in order to solve priority inversion problems among several those conditions. There have been two representative protocols: basic priority inheritance protocol and priority ceiling emulation protocol. However, these protocols cannot solve complicated priority inversion problems. In this paper, we design a protocol, called recursive priority inheritance (RPI), protocol that effectively solves the complicated priority inversion problems. Our proposed protocol is also implemented in the Linux kernel and is compared with other existing protocols in the aspect of qualitative analysis.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.380-380
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• 2023

기후변화와 도시화에 따른 개발사업으로 인하여 재해 위험성은 날로 증가하고 있다. 이로 인한 재해의 영향을 최소화하기 위해 각종 개발사업 시 자연재해대책법에 따라 사전에 자연재해에 따른 피해를 예방하기 위한 목적으로 재해영향평가 협의가 시행되고 있다. 재해영향평가 협의에서 홍수로 인한 재해예방을 위해 개발사업으로 인한 홍수유출 증가량 검토하고 저감 대책을 제시하게 된다. 이중 소규모 재해영향평가는 면적 5천m² 이상 5만m² 미만의 개발사업을 대상으로 실시되고 있으며, 이를 위한 첨두홍수량 산정 방법으로는 합리식, clark단위도법 등이 사용되고 있다. 소규모 유역의 첨두홍수량을 합리식, 단위도법 등으로 산정할 경우 도달시간이 매우 짧아 홍수량이 과다하게 산정된다. 이를 방지하기 위해 합리식에서는 강우지속기간을 늘리기 위해 일정 유입시간을 고려하고 있으며, 단위도법에서는 유역반응시간을 조정하고 있다. 기존의 연구에서 clark단위도법에서 저류상수 매개변수 보정을 7 ~ 10분으로 적용하도록 하고 있다. 본 연구에서는 화성, 양주, 청주지역의 소규모 재해영향평가협의 대상인 공장부지 조성사업의 홍수량 산정시 저류상수 매개변수 조정 사례를 조사하고 그 중 유역의 상황변화를 고려하지 않고 개발 후 매개변수 조정을 10분으로 적용한 10개 사업을 대상으로 선정하였다. 본 연구에서는 개발 후 매개변수 보정량을 10분을 7분으로 변경하여 홍수량을 산정하였다. 10개 사업 홍수량 산정결과 「재해영향평가등의 협의 실무지침 (2021.01, 행정안전부)」에서 제시하는 소유역 비홍수량의 범위인 25 ~ 35m³/s/km²에 8개 사업이 만족되었고, 2개 사업은 개발 후 비홍수량이 제시 범위를 다소 초과하였고, 홍수량의 증가는 4.7 ~ 16.3% 범위로 나타났다. 소규모 유역에서 저류상수 보정량이 홍수량 산정에 미치는 영향이 큰것을 감안하면 유역의 도시화등 상태변화 비율 및 소유역 면적별로 매개변수 조정량을 정량화하는 추가 연구가 필요하다.

• The Journal of Korean Association of Computer Education
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• v.8 no.2
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• pp.61-73
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• 2005

Mobile games have emerged as the most innovative entertainment technology, adding new revenue streams, taking advantage of the potential of wireless applications and service offerings. Mobile games, like any other types of computer game, offer a unique value for users in providing an exciting digital experience in virtual worlds. Players can become empowered through the development of new characters and strategies within games to achieve rewarding successes against the computers and other players. In this paper, we attempt to examine the motives of adolescents for playing mobile games. Based on data collected from survey, we have identified Escape, Arousal and Fantasy, Challenge and Competition, Diversion and Relaxation, Social interaction as the key motivators for playing mobile games. We also investigated the extent to which use and gratifications are predicted by demographic factors as well as by gaming experience. Statistical results confirm that most of the demographic factors played critical roles in determining the level of motivations for playing games. The results from this research might give mobile game industry some useful guidelines for developing mobile edu-game and market expansion strategy.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.5
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• pp.358-363
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• 2009

The HSPF (Hydrological Simulation Program-Fortran) model was applied to the Kyoungan stream watershed to analyze effects of watershed management plans on receiving water qualities. Utilizing BASINS 3.1 GIS program, the Kyoungan stream watershed was divided into 57 sub-basins and model input parameters were obtained, from DEM (Digital Elevation Model), land use type, stream map, and wastewater treatment facilities, etc.. The hydrologic module of the model was validated based on the measured meteorological data and stream flow data. Then the model was calibrated and verified against the field measurements of water qualities, including temperature, DO, BOD, $NO_3-N$, $NH_3-N$, Org-N, TN and TP. In most cases, there were reasonable agreements between measurements and predictions. The validated model was used to analyze the water quality improvements in the main stream of Kyoungan stream according to the watershed management plans in sub-basins, which are three different scenarios: water quality improvement in tributaries through watershed management activities, expansion and up-grade of wastewater treatment plants, and application of first and second scenarios together. It was concluded that expansion and upgrade of wastewater treatment plants would be more effective than watershed management activities. In order to improve water qualities to the satisfactory level, both watershed management and point source control must be required in the Kyoungan stream.

• Journal of Korea Water Resources Association
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• v.39 no.10 s.171
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• pp.867-880
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• 2006

Hydrological models with many parameters and complex model structures require a powerful and detailed model calibration/validation scheme. In this study, we proposed a multi-variable and multi-site calibration and validation framework for the Soil Water Assessment Tool (SWAT) model applied in the Gap-cheon catchment located downstream of the Geum river basin. The sensitivity analysis conducted before main calibration helped understand various hydrological processes and the characteristics of subcatchments by identifying sensitive parameters in the model. In addition, the model's parameters were estimated based on existing data prior to calibration in order to increase the validity of model. The Nash-Sutcliffe coefficients and correlation coefficient were used to estimate compare model output with the observed streamflow data: $R_{eff}\;and\;R^2$ ranged 0.41-0.84 and 0.5-0.86, respectively, at the Heuduck station. Model reproduced baseflow estimated using recursive digital filter except for 2-5% overestimation at the Sindae and Boksu stations. Model also reproduced the temporal variability and fluctuation magnitude of observed groundwater levels with $R^2$ of 0.71 except for certain periods. Therefore, it was concluded that the use of multi-variable and multi-site method provided high confidence for the structure and estimated parameter values of the model.

• Journal of Family Resource Management and Policy Review
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• v.28 no.1
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• pp.39-53
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• 2024

This study examines how economic factors such as income, parental support, perceived social status, and financial distress are associated with marital intentions among unmarried young adults in their 20's and 30's. Data were collected by an online survey, and a total of 567 people participated nationwide. Results from a hierarchical logistic regression suggest that (1) women's income was associated with their marital intentions, but not men's; (2) perceived social status was associated with marital intentions among both men and women; (3) men's expected parental support for marriage was associated with marital intentions; and (4) when three subfactors of the material values were included in the analysis, among women, it was found that the use of possessions to judge one's own success and that of others was positively associated with their marital intentions, and the belief that possessions and the acquisition of materials lead to happiness and satisfaction was negatively associated with their marital intentions. Further discussion is provided about the interpretation and implications of the results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.412-425
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• 2016

Recently, the influence of the residential value of new town apartment houses has been increasing in the housing market; however, there has been little study on the relationship between the housing value and customer loyalty. This study analyzed the influence of the housing value on housing satisfaction and customer loyalty. To this end, this study conducted a survey targeting 519 residents in the second term new town. Accordingly, basic statistics, reliability and hypothesis test were carried out using SPSS 21.0 and ANOVA as an analysis method. The study results are as follows. First, as a result of factor analysis of the housing value, the factor was analyzed as 6 sorts, such as safety, sociality, convenience, economic feasibility, aesthetics, and comfort. Second, safety, comfort, and convenience among the factors in the housing value were found to have a significant influence on the housing satisfaction. This means that the concepts of property and assets reflect the development of new urban city apartments. Third, a new town house purchaser's positive housing value and housing satisfaction were found to increase customer loyalty. This greater satisfaction of the current residential apartment dwellers means that they are more likely to introduce their relatives and neighbors. These results suggest that a positive outlook of a new town householder on the housing value and housing satisfaction will eventually work more on revitalizing the housing market.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.335-338
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• 2009

The process of charging an oxidizer in the liquid propellant rocket can divide into the cooling of the oxidizer tank, the high flow charge, the small flow charge, and the replenishment charge for the correction of temperature. The oxidizer of the Naro(KSLV-I) first stage uses the liquid oxygen. And the flow rate and the temperature specification corresponding to each charge mode are presented for the requirement. The flow throttling valve and heat exchanger are installed in the oxidizer filling system in order to satisfy this kind of the flow rate and temperature requirement specification. In this research, by using the Flowmaster which is a commercial one-dimension thermo-fluidic analysis program, one dimensional flow system analyses was performed to predict the exact flow rate at each specific mode. Also, the flow rate correction sensitivity of the flow control valves was analytically determined to satisfy the flow condition refinement at each mode within the limited certification test.

• Journal of Korea Multimedia Society
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• v.11 no.1
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• pp.117-128
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• 2008

Recently, as the increase in interaction between the person and the person, the people plentifully use the business card to exchange personal information. So, the people have many business cards. Thus, the people are liable to lose the business cards and finding a wanted business card is very difficult in the huge business cards in offline. And, the people think the business card is a way, which can express individuality. So, the people want to have the business card, which has individuality. Thus, this paper proposes the card system, which is satisfied to solve many problems of the card system in offline and express individuality. The proposed business card system can produce various business cards and puts contents such as video, photo, voice into business cards via mobile devices in anywhere, anytime. Also, this business card system follows the vCard format, which is a file format standard for personal data interchange. Finally, we provide with content-based business card retrieval using video and photo inserted into business cards. Thus, this paper proposes the hybrid business card system, which is satisfied to produce business cards expressed individuality and follows the vCard format.

• Journal of Digital Convergence
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• v.18 no.9
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• pp.63-70
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• 2020

This study examines whether citizen's satisfaction with police response to their victimization has an effect on the trust in the police. The data (N = 214) were collected from the North Koreans refugees residing in South Korea. One key finding shows that the North Koreans who were dissatisfied with policemen's response to their crime victimization cases report lower trust in the South Korean police. Also, the people who had ever reported a crime to the police increase their trust in the police. However, sex, education experience, car ownership, household victimization preventive measures, crime trends decrease their trust in the police. The implications and limitations were discussed for the future research.