• 한국통신학회논문지
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• 제37권8B호
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• pp.613-619
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• 2012

Long Term Evolution(LTE) 시스템은 멀티미디어 서비스와 같은 다양한 서비스를 이동 사용자에게 제공할 수 있다. 실제로 HSPA+(High Speed Packet Access plus)는 다운링크의 비트 율(bit rate)을 크게 향상 시켰으나, 다양한 멀티미디어 서비스에서 요구하는 서비스 품질을 어떻게 만족시킬 것인가에 대한 연구는 매우 미비한 상태이다. 본 논문에서는 proportional fair(PF) 알고리즘을 기반으로 하여 LTE를 위한 효율적인 패킷 스케쥴링 알고리즘을 제안하였다. 제안된 알고리즘에서는 패킷 스케쥴링을 할 때 패킷의 우선순위를 결정하는 가장 중요한 요소인 트래픽 클래스의 가중치와 순간 사용자 데이터 전송율을 최적화 하였다. 또한 다중 셀(multi-cell) 환경에서 LTE를 통해서 사용자에게 전송되는 멀티미디어 트래픽을 시뮬레이션 함으로써 제안된 알고리즘의 성능이 향상되었음을 보였다.

• 정보보호학회논문지
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• 제19권1호
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• pp.3-11
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• 2009

이메일 시스템에서 전방향 안전성(forward secrecy)이란, 메일 사용자와 메일 서버가 장기간 사용하는 비밀키(long-term key)가 노출되더라도 이전 세션들에서 전송된 이메일 메시지의 기밀성(confidentiality)이 보장되는 것을 말한다. 기존 전방향 안전성을 지원하는 이메일 프로토콜들에서는 사용자의 공개키를 사용하기 때문에 공개키에 대한 인증을 위해서는 공개키 기반구조(PKI, Public Key Infrastructure)의 구축이 반드시 필요하다. 본 논문에서는 PKI의 구축이 필요 없이, 사용자의 메일 계정의 패스워드만을 이용하는 전방향 안전성을 보장하는 패스워드 기반의 이메일 프로토콜을 제안한다. 본 논문에서 제안하는 패스워드 기반의 이메일 프로토콜은 인증된 공개키가 필요 없으므로 제한된 자원의 모바일 환경 등에 적합하다.

• Asia pacific journal of information systems
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• 제20권3호
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• pp.73-90
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• 2010

Although research on acceptance of information systems provides useful insights in understanding users' behavior, we need to further understand factors that cause long-term or continued use. This article therefore examines the role of users' maximizing tendency (i.e., individual differences in pursuing the best option) in continuance intention of Web sites. By controlling for disconfirmation, ease of use, and product involvement, we empirically investigate the relationships between satisfaction, usefulness, and continuance intention to online bookstore Web sites. As suggested by the information technology continuance model, the effects of satisfaction to and perceived usefulness on continuance intention to Web sites are positive for individuals with low maximizing tendency (i.e., satisficers). Satisfaction and usefulness, however, are not associated with continuance intention for individuals with a high maximizing tendency (i.e., maximizers). The implications for both researchers and practitioners are discussed.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1980년도 학술대회지
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• pp.229-236
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• 1980

Tow groups of subjects were studied before, during, and after long-term use of commercial Panax ginseng preparations. Group A (n = 10) consisted of users who also used other psychomotor stimulants including caffeine, while subjects in Group B (n = 8) used no drugs other than ginseng. During 12 weeks of regular ginseng use, users in Group A showed signs of central nervous system stimulation and reported feelings of well-being. Two subjects manifested possible allergic reactions while one developed a ginseng abuse syndrome marked by hypertension, nervousness, sleeplessness, skin eruptions, edema, and morning diarrhea. This syndrome was associated with excessive dosages, concomitant intake of caffeine, and possible allergic reactions. Subjects in Group B reported stimulation and feelings of well-being while showing some signs of nervousness. One subject developed a possible contact urticarial reaction to a ginseng cosmetic. All adverse reaction were transient and disappeared when ginseng use was discontinued. It is suggested that adverse reactions can be prevented by moderate use of standardized ginseng preparations while restricting use of other psychomotor stimulants.

• International Journal of Advanced Culture Technology
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• 제10권3호
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• pp.156-163
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• 2022

Social services are divided into care services and other support services for the elderly, children and the disabled. These social services are the subject of great policy interest in that they can create two effects at the same time: increase in labor demand for service providers and increase the possibility of long-term accumulation of human capital for service recipients. Therefore, this study aims to confirm the hypothesis according to whether the use of social services affects family relationships and the effects of social service users' psychological adaptation on marital and parent-child relationships even when other related variables are controlled. The final result of this thesis is a regression analysis to find out the effect of psychological adaptation on the family relationship, spouse relationship, and relationship with children of subjects who have experience using social services. -.661, p=0.001), the higher the psychological adaptation, the higher the spouse satisfaction (β=.465, p=0.001) and relationship satisfaction with children (β=.360, p=0.001). In other words, it was found that the more depressed the psychologically, the more negative the relationship with spouse and children.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권8호
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• pp.2626-2646
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• 2014

This study presents a power and Physical Resource Blocks (PRBs) joint allocation algorithm to coordinate uplink (UL) interference in the device-to-device (D2D) underlaying Long Term Evolution-Advanced (LTE-A) networks. The objective is to find a mechanism to mitigate the UL interference between the two subsystems and maximize the weighted sum throughput as well. This optimization problem is formulated as a mixed integer nonlinear programming (MINLP) which is further decomposed into PRBs assignment and transmission power allocation. Specifically, the scenario of applying imperfect channel state information (CSI) is also taken into account in our study. Analysis reveals that the proposed PRBs allocation strategy is energy efficient and it suppresses the interference not only suffered by the LTE-A system but also to the D2D users. In another side, a low-complexity technique is proposed to obtain the optimal power allocation which resides in one of at most three feasible power vectors. Simulations show that the optimal power allocation combined with the proposed PRBs assignment achieves a higher weighted sum throughput as compared to traditional algorithms even when imperfect CSI is utilized.

• 한국통신학회논문지
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• 제35권7B호
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• pp.1001-1008
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• 2010

본 논문에서는 해상무선통신환경에서 선박의 위치에 따라 속해있는 네크워크 운영자들 간의 장기간(long-term)의 우선순위(priority) 및 서비스 클래스간의 우선순위 등을 고려한 동적스펙트럼할당(DSA: Dynamic Spectrum Allocation) 알고리즘을 제안한다. 제안한 DSA 알고리즘은 네트워크 운영자간의 각기 다른 서비스 클래스의 트래픽 패턴에 대해서 동적으로 스펙트럼을 공유하고 할당하여, 기존의 고정 스펙트럼 할당방식에 비해 사용자들에게 요구하는 스펙트럼 대역폭을 충분히 제공할 수 있어 서비스 만족율을 향상시킴을 보였다. 따라서 제안한 알고리즘은 해상무선통신환경에서도 스펙트럼 공유와 동적 할당을 통한 운영이 가능함을 보여 육상의 유휴 스펙트럼 자원을 활용할 수 있음을 제시하였다.

• 지역사회간호학회지
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• 제19권3호
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• pp.480-494
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• 2008

Purpose: The study was to got basic data on the well-being of middle-aged people concerning their preparation for their upcoming old age and their quality of life. Methods: The subjects were 440 people aged between 40 and 59 living in Seoul and Gyeonggi-do. Results; First, Physical Preparation for old age was affected by religion, children, health, monthly income, and economical status, and these factors were shown statistically significant. Emotional preparation and spiritual Preparation were also related to the above-mentioned factors. Secondly, in the subjects' mental picture, a nursing home was a place for the aged without anyone who is going to take care of them and without abilities to care of themselves. Preference for nursing home was based on two factors. i.e., nursing and treatment care. and the cost was about one million won per month. Also they wanted that the government should pay a certain amount for private users. Conclusion: Therefore, people should lead a life of good health-related habits along with economical preparation for their old age.

• 수산해양교육연구
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• 제25권2호
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• pp.458-477
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• 2013

The purpose of this research is to define the problems of the Fisheries Census of Korea and to make better policies for improvement. In order to complete the purpose, the research team has firstly conducted a survey in the six regions to reinvestigate the yes or no for accuracy of the primary data related to the Fisheries Census. Moreover, the team has defined the problems of the Fisheries Census through conducting a survey for the experts and users of the fisheries statistics. Also, the team has derived the short/long term improvement of Fisheries Census through out this survey. This study has proposed that the name of census should be changed from the Fisheries Census to the Fishing Industry Census, the owners of distribution & processing companies, and their employees should be included in order to figure out the total size of the fishing industry and to plan right policies. In addition, the right information can evaluate the long-term planning for the fishing industry. The proposals from this study require a lot of changes on the Fisheries Census; so, it is impossible to adopt the proposals right from the Fisheries Census of 2015. Therefore, the changes should be adopted from the next Fisheries Census.

• 전자공학회논문지
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• 제50권7호
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• pp.27-33
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• 2013

본 논문에서는 차세대 셀룰러 시스템을 위한 사용자들 간 다중 포인트 협력 통신 (CoMP; Coordinated Multi-Point) 기법에 대하여 설계하고 이를 바탕으로 성능 분석이 이루어졌다. LTE-Advanced (Long Term Evolution-Advanced) 시스템에서 몬테카를로 모의실험이 이루어졌으며, CDF (Cumulative Distribution Function) 그래프를 통해 그 성능을 확인한다. CoMP를 사용하였을 때 성능이 향상되는 것을 확인하였으며, 스케줄링과 프리코딩 등 여러 기법을 추가로 적용하였을 때 더 좋은 결과를 얻는 것을 확인한다.