• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.107-110
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• 2004

IEEE 802.15.3 is wireless Medium Access Control(MAC) and Physical Layer(PHY) specification for high rate WPAN (Wireless Personal Area Network). IEEE 802.15.3 MAC Layer provides Qos with three kinds of acknowledgements; No acknowledgement, Immediate acknowledgement, and Delayed acknowledgement. This paper presents how to improve QoS with new acknowledgement method called Delayed Negative acknowledgement. This paper describes the method of using Delayed Negative acknowledgement and presents the calculation of QoS improvement by using Delayed Negative acknowledgement.

• 근관절건강학회지
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• 제3권2호
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• pp.151-165
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• 1996

The purpose of this study is to describe the acknowledgement of the cause of the illness in the patients with RA. I used naturalistic inquiry as a research methodology. The purposive sampling was conducted. 23 subjects who experienced RA, lived in middle-sized city in Korea, and 19 women and 4 men. I collected data using indepth structured interview, "What is the acknowledgement of the cause of the illness?" I used inductive data analysis-such as unitizing and categorizing. This process is used constant comparative method. Summerising the results of this study, the acknowledgement of the cause of the illness are composed of physical constitution, fatalism, the attribution of physical overload, the attribution of stress, the lack of nutrition. The factors which affect the acknowledgement of the cause of the illness are composed of internal factors, external factors, environmental factors. The internal factors are the weakness of the childhood, the illness experience in the family members, juvenile rheumatoid arthritis, personality, lack of nutrition. The external factors are pregnancy, delivery, role burden and conflict, economic problem. The environmental factors are humid condition, abrupt environmental change. It is needed to explaine the coping pattern according to the acknowledgement of the cause of the illness in the next research.

• Journal of Communications and Networks
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• 제18권2호
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• pp.238-245
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• 2016

A sequence number checking technique is proposed to improve the performance of TCP connections in mobile ad hoc networks. While a TCP connection is initialized, a routing protocol takes the responsibility for checking the hop count between a source and destination pair. If the hop count is greater than a predefined value, the routing protocol decides to use a proxy node. The responsibility of a proxy node is to check the correctness of data packets and inform the missing packets by sending an acknowledgement from a proxy node to the source node. By doing so, the source node is able to retransmit any missing packet in advance without waiting until an end-to-end acknowledgement is received from the destination. Simulation results show that the proposed mechanism is able to increase throughput up to 55% in static network and decrease routing overhead up to 95%in mobile network.

• 한국콘텐츠학회논문지
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• 제9권5호
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• pp.322-331
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• 2009

본 연구는 단양군이 개발한 3개의 고구려 음식과 19개의 향토음식에 대한 인지도와 선호도를 분석하여 향토음식 활성화의 기초자료로 제시하고자 한다. 설문지는 거주민과 관광객에게 각 150부씩 배포하고 261부를 회수하였고, 232부를 이용한 분석결과는 다음과 같다. 첫째, 22개의 향토음식에서 '올갱이 해장국', '도토리 묵밥', '소백산 산채 비빔밥', '더덕마늘구이'가 인지도와 선호도에서 높게 나타났다. 둘째, 인지도 분석에서 남성은 '올갱이 해장국'과 '남한강민물매운탕', 거주민들은 '곤드레 마늘솥밥', '올갱이 해장국', '남한강 민물매운탕과 회', '소백산 산채비빔밥'을 높게 인지하는 것으로 나타났다. 따라서 집적화 특징을 갖고 있는 향토음식은 단지가 형성되어 많은 관광객을 유인하고 있는 반면에 최근에 개발된 고구려 음식은 영화셋트장 주변에 음식점 단지를 형성하고 지리적 표시제도 도입 또는 상품명에 단양을 넣어 인지도 제고와 지역경제 활성화에 도움이 될 것이다. 셋째, 선호도 분석에서 남성은 '마늘육회', 거주민들은 '곤드레 마늘솥밥', '올갱이 해장국', '소백산 산채비빔밥', 50대는 '곤드레 마늘솥밥', '남한강 민물매운탕', '소백산 산채비빔밥을 더 선호하는 것으로 나타났다. 따라서 향토음식을 선호하는 노년층과 달리 젊은층을 어필할 수 있는 음식 맛과 각 재료의 대표적인 음식효능을 이용하여 선호도를 강화시켜야 할 것이다.

• 한국의류산업학회지
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• 제21권1호
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• pp.46-58
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• 2019

This study analyzes the effects of lifestyle on wetsuits purchasing behavior and identifies various characteristics among lifestyle groups. A questionnaire survey of 213 domestic consumers with water sport activity and wetsuits experience indicated the following results: 1) Lifestyle factors were analyzed as 6 factors: social relation ships, development orientation, trend & appearance, domestic, positive acknowledgement of hobbies, pursuit of practicality. And the wetsuits selection criteria was 4 factors: wearing fitness, product information, design, reputation. 2) Social relationships, development orientation, positive acknowledgement of hobbies and pursuit of practicality factors had a positive effect fitness. Trend & appearance, development orientation, and pursuit of practicality factors had a positive effect on product information factors ; in addition, development orientation, and trend & appearance, a positive acknowledgement of hobbies factors had a positive effect design factors. Social relationships, trend & appearance, and pursuit of practicality factors had a positive effect on reputation factors. However, trend & appearance factors negatively affected the wearing fitness factors and the positive acknowledgement of hobbies factors had negative effect on product information, reputation factors. 3) The three groups of lifestyle factors showed differences in monthly average purchasing of clothes, average annual purchasing expenditures for water sports related products, number of water sport activity days and frequency, product selection criteria.

• 한국정보과학회논문지:시스템및이론
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• 제26권12호
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• pp.1493-1503
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• 1999

ATM Clustering System과 같이 SAN(System Area Network) 환경에서 동작하는 시스템은 낮은 지연시간과 넓은 대역폭의 네트워크가 필수적이나 기존의 에러 복구 프로토콜들은 이러한 요구를 충족시키기에는 큰 오버헤드를 가지고 있다. 제안된 새로운 에러 복구 프로토콜은 ATM Clustering System 환경에서 최적의 성능을 나타내는 light-weight 프로토콜로 에러가 없는 상황과 에러 복구가 진행중인 상황에 따라 acknowledgement 주기를 적응적으로 변화시키는 adaptive acknowledgement scheme를 제안하여 적용하였다. 제안된 프로토콜은 상용 툴인 SDT를 이용한 논리 검증 받았고, DEVSim++ 환경에서의 성능 분석을 통해 프로토콜이 최상의 성능을 보이기 위한 파라메터 값을 찾았고, 이 값을 적용하였을 때의 성능을 기존의 프로토콜과 비교하여 제안된 프로토콜이 더 우수함을 확인하였다.Abstract While a system working with SAN, such as ATM Clustering System, requires a network with low latency and wide bandwidth, the previous error recovery protocols have a serious network overhead to satisfy this requirement. The suggested error recovery protocol is a light-weight protocol which can shows its best performance at ATM Clustering System and uses a newly suggested adaptive acknowledgement scheme. In the adaptive acknowledgement scheme, the period of acknowledgement is dynamically changed depending on the state of the network. We proved the logical correctness of our protocol with SDT and did performance analysis with DEVSim++. From the analysis, we found the optimal parameter values for best performance and showed that our protocol works better than the previous error recovery protocols.

• 대한안전경영과학회지
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• 제7권3호
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• pp.109-120
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• 2005

A company is liable for its products and has the responsibility to make good on any loss or damage incurred by the user of its product. The purpose of the Product Liability Act(PLA) is to protect consumers against damage caused by defective products, and contribute to the safety of the citizen's life and the sound development of the national economy by regulating the liability of manufacturers, etc. for damages caused by the defectiveness of their products. In this study, the cognition levels of consumers and producers for PLA were surveyed. The cognition levels of four factors of acknowledgement, comprehension, necessity and impact for PLA were assessed. The results were as follows : i) Acknowledgement and comprehension levels of consumer were assessed low but they assessed necessity and impact of PLA high; ii) Producers assessed necessity and impact of PLA higher than their acknowledgement and comprehension levels; iii) Overall cognition levels of producers were higher than those of consumers.

• 한국멀티미디어학회논문지
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• 제12권12호
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• pp.1769-1777
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• 2009

With the advent of the ubiquitous technology age, the progress of network technology has enabled a robust sensor communication, not just in cities, but also in poor surroundings such as deserts, polar regions, or underwater environments. In this paper, we propose a Multiple Acknowledgement (MA) technique to replace the conventional Automatic Repeat request (ARQ) technique. The MA mechanism is to send an Ack to many receivers simultaneously. The CH (master, coordinator) of the unit cluster broadcasts a Beacon frame where Ack information of the previously transmitted data is included. This technique can reduce the number of transmissions and overhead significantly. The proposed technique is a scheme improving the efficiency of an underwater sensor network where the uplink data transmission is the mainstream. The Performance of the ARQ, Block Ack, Pervasive Block Ack and the proposed method were compared with one another and analyzed. The proposed method showed significant performance improvement as compared with the ARQ, BA, and PBA in its channel efficiency.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 춘계학술발표대회
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• pp.1300-1302
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• 2009

인간 생활의 질적인 향상을 위해, 각종 시스템이 연구되고 있다. 특히 작고 설치가 용이한 센서를 중심으로 Ubiquitous 분야가 발달하고 있으며, 센서 네트워크에 대한 연구가 활발히 진행되고 있다. 특히 일반적인 생활에는 물론 의료, 노약자의 보호, 위험 감지 등의 중요한 분야에까지 센서 네트워크가 활용됨으로써 데이터 전송의 정확성과 신뢰성은 중요한 문제로 대두되었다. 이에 본 논문에서는, 센서의 특성과 무선 통신의 특징을 고려하여 에너지 효율성 및 데이터 전송의 신뢰성을 향상시키기 위한 방법을 제시하고자 한다. 특히 RSSI 신호와 채널 에러율을 함께 이용하여 각 노드 경로별 신뢰도를 계산하고, 이에 따라 선택적으로 Acknowledgement를 사용하며 오버히어링 문제를 역으로 이용하여, 묵시적 Acknowledgement로 사용함으로써 에러율이 높고 에너지가 한정되어있는 무선 센서 네트워크에서 계속적인 ACK/NACK 사용으로 인한 에너지 소비 및 트래픽 낭비를 줄이고자 한다.

• 한국통신학회논문지
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• 제28권4B호
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• pp.288-297
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• 2003

TCP Reno 는 하나의 윈도우 내에서 다수 개의 패킷 손실이 발생하는 경우 손실된 패킷들을 효율적으로 복구하는 것이 불가능한 문제점을 가지과 있다. 이 문제점을 개선하기 위해서 설계된 TCP New-Reno 는 부분 스인 패킷(partial acknowledgement)를 통해 fast recovery를 연장함으로써 다수 개의 패킷 손실이 발생하더라도 이들을 재전송에 의해 복구하는 것이 가능하다. 그러나 TCP New-Reno 역시 재전송 패킷들이 다시 손질되는 경우 불가피한 RTO(Retransmission Timeout)가 발생한다는 문제점을 가지고 있다. 이런 문제점을 개선하기 위해서 중복 승인 패킷 수를 근거로 재전송 패킷 손실을 감지할 수 있는 DAC(Duplicate Acknowledgement Counting) 알고리듬을 제안한다. TCP Reno. TCP New-Reno 그리고 DAC를 사용하는 경우에 대해 손실 복구 과정을 정확하게 모델링하고 손실된 패킷이 복구되기 위한 조건들을 유도한다. 임의 패킷 손실 확률에 대한 손실 복구 확률을 수학적으로 계산하고 이를 통해 DAC가 TCP New-Reno 의 손실 복구 기능을 향상시킬 수 있다는 것을 보인다.