• Proceedings of the IEEK Conference
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• 2004.06a
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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.

• Journal of muscle and joint health
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• v.3 no.2
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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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• v.18 no.2
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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.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.322-331
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• 2009

The purpose of this study is to suggest guidelines for analysis acknowledgement, preference with 19 local foods and 3 Koguryo foods in Dan Yang county. The questionnaires are distributed each 150 residence and tourist who visited in Dan Yang county, collected 261, then used for data analysis 232. The results are as followed. First, 4 items among 22 regional foods' marsh snail broth', 'mixed rice with acorn-starch paste', 'mixed rice with various herb', and 'baked deodeok' are ranked highly in acknowledgement and preference. Second, 4 variables which are sex, age, residence or tourists, and income had significant in acknowledgement. Therefore, making Koguryo food town near movie setting place, introduction geographically mark system, and put Dan Yang mark into merchandise would be increased acknowledgement, and also promoted local economic. Third, 3 variables except income had significant in preference. Therefore, functional effect of each food and taste for young generation would be reinforced in preference.

• Fashion & Textile Research Journal
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• v.21 no.1
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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.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.12
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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.

• Journal of the Korea Safety Management & Science
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• v.7 no.3
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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.

• Journal of Korea Multimedia Society
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• v.12 no.12
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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.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4B
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• pp.288-297
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• 2003

The fast retransmit and fast recovery algorithm of TCP Reno, when multiple packets in the same window are lost, cannot recover them without RTO (Retransmission Timeout). TCP New-Reno can recover multiple lost packets by extending fast recovery using partial acknowledgement. If the retransmitted packet is lost again during fast recovery, however, RTO cannot be avoided. In this paper, we propose an algorithm called "Duplicate Acknowledgement Counting(DAC)" to alleviate this problem. DAC can detect the retransmitted packet loss by counting duplicate ACKs. Conditions that a lost packet can be recovered by loss recovery of TCP Reno, TCP New-Reno and TCP New-Reno using DAC are derived by modeling loss recovery behavior of each TCP. We calculate the loss recovery probability for random packet loss probability numerically, and show that DAC can improve loss recovery behavior of TCP New-Reno.