• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.722-725
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• 2012

최근 이슈가 되고 있는 클라우드 컴퓨팅, 빅데이터, 모바일 등 다양한 분야에서 공개SW 기반 시스템을 도입하여 적용하는 사례가 증가하고 있으나, 수많은 공개SW 중 신뢰성 있는 솔루션을 선택하는 것은 많은 시간과 비용이 발생한다. 이에 공개SW 도입 시 고려해야하는 항목을 도출하여 선정지표를 개발하였으며, 실제 공개SW 도입을 위한 조사 및 선정 단계에서 선정지표를 활용하여 업무 적합성, 성숙도 등을 고려한 최적의 공개SW 선정할 수 있는 기준을 제공하고자한다. 또한 선정지표를 활용하여 WEB, WAS, DB 등 공개SW 솔루션에 대한 평가 사례를 살펴보고, 향후 선정지표를 활용할 수 있는 방안을 제안한다.

• ETRI Journal
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• 제37권4호
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• pp.717-726
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• 2015

In this paper, we study an asymmetric two-way relaying network where two source nodes intend to exchange information with the help of multiple relay nodes. A hybrid time-division broadcast relaying scheme with joint relay selection (RS) and power allocation (PA) is proposed to realize energy-efficient transmission. Our scheme is based on the asymmetric level of the two source nodes' target signal-to-noise ratio indexes to minimize the total power consumed by the relay nodes. An optimization model with joint RS and PA is studied here to guarantee hybrid relaying transmissions. Next, with the aid of our proposed intelligent optimization algorithm, which combines a genetic algorithm and a simulated annealing algorithm, the formulated optimization model can be effectively solved. Theoretical analyses and numerical results verify that our proposed hybrid relaying scheme can substantially reduce the total power consumption of relays under a traffic asymmetric scenario; meanwhile, the proposed intelligent optimization algorithm can eventually converge to a better solution.

• 한국조리학회지
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• 제23권6호
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• pp.27-35
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• 2017

The purpose of this study was to examine the causal relationship among restaurant selection attributes and customer satisfaction and recommendation tastes for young people in their twenties who use tickets for Rail-ro. Data collection was conducted to utilize questionnaire survey with online and offline distribution. The collected data were analyzed using a statistical program SPSS 21.0 with frequency analysis, reliability analysis, factor analysis, and regression analysis. The results of the study showed that Internet search is the most common source of information about restaurants during the trip, and restaurant choice attributes have an important impact on customer satisfaction, food quality, employee service and reputation, but hygiene did not have a big effect on customer satisfaction. In addition, customer satisfaction has a significant effect on recommendation intention. Concluding the results from this study, it investigated the significant attributes for customers selection of restaurants and provide meaningful advice for market managers to make useful marketing strategies to attract more clients and augment economic benefits.

• 대한전자공학회논문지TC
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• 제46권11호
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• pp.18-24
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• 2009

협력다이버시티는 무선채널페이딩에 강건하고 다중안테나기술에 비해 낮은 단말기 구현 복잡도를 제공하는 장점으로 인해 최근 각광받고 있는 기술이다. 본 논문에서는 새로운 중계단말기 선택 기법과 결합된 예측 기반 의사결정을 이용하는 적응적 협력 선택기법을 제안한다. 제안된 기법에서 수신단말기는 중계단말기와 수신단말기간의 순간 채널 상태 정보를 이용하여 선택된 중계단말기로부터의 전송이 성공할지 실패할지 여부를 예측한다. 수신단말기는 예측 정보를 이용하여 결정된 협력 선택 명령을 전체 네트워크에 전달한다. 실험결과를 통해 새로운 중계단말기 선택 기법과 결합된 적응적 협력 선택기법이 기존 기법들에 비해 불능확률(outage probability)을 줄이고, 시스템 성능(throughput)을 개선하며, 전송 전력을 절약하여 네트워크의 수명(lifetime)을 연장시키는 것을 보인다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.2894-2909
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• 2015

As the number of mobile devices such as smart phones and tablets explodes, the need for new services or applications is also rapidly increasing. Smart class application is one of the emerging applications, in which most of contents are distributed to all members of a class simultaneously. It is highly required to select relay nodes to cover shadow area of radio as well as extend coverage, but existing algorithms in a smart class environment suffer from high control packet overhead and delay for exchanging topology information among all pairs of nodes to select relay nodes. In addition, the relay selection procedure should be repeated in order to adapt to the dynamic topology changes caused by link status changes or device's movement. This paper proposes the learning based relay selection algorithm to overcome aforementioned problems. The key idea is that every node keeps track of its relay quality in a fully distributed manner, where RQI (Relay Quality Indicator) is newly defined to measure both the ability of receiving packets from content source and the ability of successfully relaying them to successors. The RQI of each node is updated whenever it receives or relays broadcast packet, and the node having the higher RQI is selected as a relay node in a distributed and run-time manner. Thus, the proposed algorithm not only removes the overhead for obtaining prior knowledge to select relay nodes, but also provides the adaptability to the dynamic topology changes. The network simulation and experimental results prove that the proposed algorithm provides efficient and reliable content distribution to all members in a smart class as well adaptability against network dynamics.

• 한국통신학회논문지
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• 제34권7A호
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• pp.530-539
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• 2009

Wireless Relaying is a promising solutions to overcome the channel impairments and provides high data rate coverage that appear for beyond 3G mobile communications. In this paper we present end to end BER performance of dual hop wireless communication systems equipped with multiple Decode and Forward relays over Rayleigh fading channel with the best relay selection. We compare the BER performance of the best relay with the BER performance of single relay. We select the best relay based on the end to end channel conditions. We further calculate the outage probability of the best relay. It is shown that the outage probability of the best relay is equivalent to the outage probability when all relays take part in the transmission. We apply Orthogonal Space Time Block coding(OSTBC) at the source terminal. Numerical and simulation results are presented to verify our analysis.

• 한국병원경영학회지
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• 제8권1호
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• pp.95-111
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• 2003

The purpose of this study was to evaluate the information searching behavior of consumer by type of medical institution. A questionnaire survey was conducted of 1,507 persons who were selected through a multi-stage stratified area cluster sampling in nationwide level, excluding Jeju-Do. Personal survey was conducted through door-to door survey from 27 July to 10 August 1999. The main results of this research was as following; 1. The proportion of information searching of respondents ranged from 91.5-95.2%. Even though the proportion of user in university hospital was slightly high, there was not significant statistically by type of medical institution. In terms of information source, personal informer was most common information source in all type of medical institution. Public informers were more frequently used in university hospital visitors and professional informer in general and university hospital visitors. 2. Comparing to searching intensity, user informer and professional informer's influences were more powerful, but not statistically significant. In analysis of unit influence for information source, written informer or public informer was more powerful in clinic visitor, professional informer and written informer in university hospital visitor. 3. Information which consumer want to know mostly were about on special potential and career of physician. The clinic visitor wanted to know about institutional location and kindness of medical personnel. The university hospital visitor also wanted to know about facilities and convenience of process. Comparing to institution selection criteria of consumers at 1991, quality related criteria were recognized more importantly in outpatient and dental services. But in case of inpatient services, convenience factor was recognized more importantly. In conclusion, the effort for specific marketing plan by type of medical institution should be needed. And more concern on information searching behavior of consumer will be needed.

• 한국정보통신학회논문지
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• 제17권10호
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• pp.2395-2402
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• 2013

본 논문에서는 40MHz의 대역폭과 개선된 선형성을 가지는 active-RC channel selection filter (CSF)가 제안된다. 제안되는 CSF는 5차 butterworth 필터로써 한 단의 1차 low pass 필터와 두 단의 biquad 기반의 2차 low pass 필터, 그리고 DC offset 제거를 위한 DC 피드백 회로로 구성된다. CSF의 선형성을 개선하기 위해 스위치로 사용되는 MOSFET의 body를 source 노드로 연결한다. 설계된 CSF의 대역폭은 10MHz, 20MHz, 그리고 40MHz로 선택될 수 있으며, 전압 이득은 0dB에서 24dB까지 6dB의 단위로 조정된다. 제안된 CSF는 1.2V 40nm의 1-poly 8-metal CMOS 공정에서 설계된다. 설계된 CSF가 40MHz의 대역폭과 0dB의 gain을 가질 때, OIP3는 31.33dBm이고 in-band ripple은 1.046dB, IRN는 39.81nV/sqrt(Hz)로 시뮬레이션 검증되었다. CSF의 면적과 전력소모는 각각 $450{\times}210{\mu}m^2$와 6.71mW 이다.

• 정보처리학회논문지C
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• 제8C권1호
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• pp.60-67
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• 2001

인터넷에서 멀티미디어 서비스를 지원하기 위한 멀티캐스트 프로토콜은 트리 구성 방식에 따라 공유 트리 방식과 소스 기반 트리 방식으로 나눌 수 있는데, 공유 트리 방식이 확장성 측면에서 보다 우수하다고 알려져 있다. 공유 트리 방식에서 QoS를 만족시키기 위해 고려해야 할 핵심 사항 중 하나인 RP (Rendezvous Point) 선정에 대하여 일반적으로 QoS 제약 조건에 따라 별도의 과정을 거쳐 RP를 계산하는 방식으로 연구가 되고 있다. 또한 멀티캐스트 그룹 멤버가 동적으로 가입 또는 탈퇴를 할 경우에는 초기에 설정된 RP가 신규 멤버까지는 QoS를 만족시키지 못하는 경우가 발생하게 되므로, 신규멤버 까지 QoS를 보장하는 새로운 RP를 재선정할 필요가 있는데, RP재선정에 관한 기존 연구는 매우 미흡한 실정이다. 본 논문에서는 공유 트리 방식에서 RP 초기 선정 방식과 RP 재선정 방식에 RTCP(Real Time Control Protocol) 패킷을 이용하는 새로운 기법을 제안한다. 본 논문에서 제안하는 방식은 멀티미디어 서비스를 제공할 때 이용하는 RTCP 패킷을 그대로 활용함으로써 RP계산을 위한 별도의 정보 수집 과정을 필요로 하지 않는다. 모의 실험을 통하여 제안된 방식이 초기 RP선정 시 에는 임의 선정, 위상 기반 선정 방식보다 40∼50% 정도, 멀티캐스트 그룹멤버의 동적 변화 시에는 초기 RP를 그대로 이용하는 방식보다 50% 정도의 개선 효과를 보였다.

• 보건교육건강증진학회지
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• 제7권2호
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• pp.15-21
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• 1990

It is evidenced that the mass media can play an important role in communicating information to the public. Although some campaigns have failed to achieve success, application of mass communication principles should increase the likelihood of effectiveness. Specifically, campaign strategies should attempt to select message sources that are perceived as credible by the audience. In designing and disseminating messages, the quality of content should be emphasiged as well as the quantity of presencation. The context of message reception should be carefully considered. Selection of channels depends on the configuration of source, superior for most purposes. The crucial role of precampaign audience analysis should not be overlooked.