• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(D)
• /
• pp.372-374
• /
• 2012

급속도로 증가하는 모바일 데이터 트래픽으로 인해 현재 이동통신 기술에서 모바일 트래픽 감소와 네트워크 효율 증대가 가능한 기술이 필요시 되고 있다. D2D 통신은 인접한 기기간의 직접 통신을 지원함으로써 기지국에서의 트래픽 과부하를 분산시키고 기기 간 인접함을 이용해 놓은 전송속도, 낮은 전송시간, 낮은 전력소모의 이득을 얻을 수 있으며 기지국을 이용한 통신과의 주파수 재사용으로 인한 자원 재활용 이득을 얻을 수 있다. 이러한 이점으로 인해 D2D는 차세대 이동통신 기술의 중요한 요소로 여겨지고 있으며 표준화 단체와 여러 기업에서 D2D를 활용한 차세대 이동통신 기술을 개발하는데 많은 투자를 하고 있다. 본 논문에서는 D2D에 대한 설명과 Qualcomm 사의 D2D 기술인 FlashLinQ, Nokia 사의 D2D 통신기술에 대하여 알아보고 미래 이동통신 환경에서 D2D 기술을 활용한 다양한 서비스 시나리오를 분류하고 이에 대한 요구사항을 정리해 봄으로써 D2D를 활용한 이동통신기술 개발의 초석을 마련한다.

• 간호행정학회지
• /
• 제8권2호
• /
• pp.283-293
• /
• 2002

Purpose: The purpose of this study was to define cost-countable perioperative nursing activities and to analyze the cost of each nursing activities based on the Resource-Based Relative Value Scale (RBRVS). Method: Researcher and 3 research assistants observed and documented the 83 operating patients in order to measure nursing time for each of the perioperative nursing activities. And then, 35 operating room nurses with at least one year of perioperative nursing experience were observed for the RBRVS of perioperative nursing activities. Finally, the direct and indirect nursing costs were estimated. Result: Nursing costs of 25 nursing activities were estimated using the RBRVS. Most expensive nursing activities were delivery of the instrument and implement for OP team (9,780 won per hour) and behavior of wash, pack, disinfect the instrument (6,770). Conclusion: Based on the relative values of each perioperative nursing activities estimated in this study, proper medical reimbursement system should be established in a near future.

• 청정기술
• /
• 제3권1호
• /
• pp.88-95
• /
• 1997

Energy required, air emission, and solid waste generation are calculated with available foreign data ad domestic status using Life Cycle Analysis in order to compare the environmental impact of beverage containers such as PET bottle, aluminum can, glass bottle, and paper pack. Glass bottles are found to be the worst acceptability when considering only recycling rate of glass cullet, however it becomme the best when the refill(reuse) rate of glass bottles is accounted into. To assess tile current and future environmental impact of beverage containers, energy required, air emission, solid waste generation of current data and recycling goals are compared. As a result of the study, recycling of each containers and the reuse of glass bottles must be increased by governmental enforcement to reduce the environmental impacts by beverage containers. Further study on this subject using detailed LCA(life cycle assessment) data should be implemented for the exact environmental and economic assessment.

• 한국환경성돌연변이발암원학회지
• /
• 제22권2호
• /
• pp.83-89
• /
• 2002

The single cell gel electrophoresis (comet) assay is one of the useful tools for the study of genetic damage in humans exposed to environmental mutagens and carcinogens. This study was undertaken to evaluate the status of DNA damage in peripheral lymphocytes depending on their sex, age, smoking habits, and other factors in normal healthy Korean population. The 99 volunteers included in the study and out of these, 36 volunteers were smoker and 63 volunteers were non-smoker aged between 20-59 years. All individual answered a questionnaire that assessed their general information including smoking habits and the extent of the environmental tobacco smoke (ETS) exposure, and blood samples were obtained. There was a statistically significant difference in the extent of DNA damage between smoker and non-smoker (p<0.001). A significant difference was also observed between male and female (p<0.001) and amongst the different group of age (p<0.005), however, correlation analysis showed that only smoking habit was a significant factor for DNA damage. No significant effect of smoking duration, number of cigarettes smoking a day, SPY (smoke pack years) in smokers and environmental tobacco smoke exposure in non-smokers on the status of DNA damage was observed.

• 한국방사선학회논문지
• /
• 제6권5호
• /
• pp.409-414
• /
• 2012

본 연구는 나노 조영제를 이용하여 분자영상을 획득하고 이와 동일한 조건의 일반영상을 획득하여 두 영상을 DWT(Discrete Wavelet Transform)로 변환하여 분자영상과 일반영상간의 차이를 분석하였다. 현재까지의 분자영상 기술은 나노 조영제를 이용한 MR 영상과, PET를 이용한 분자영상 연구가 주류를 이루고 있다. MRI를 이용한 동일병변의 일반영상과 분자영상을 DWT로 분석한 결과 병변이 존재하는 블록에서는 병변이 있음을 예시하여 주는 고주파 특징값이 일반영상과 분자영상 모두 더 높게 나타나는 것을 알 수 있었다. 특히 고주파 영역의 특징추출값은 분자영상이 더 높게 나타남을 알 수 있었다.

• 대한임상전기생리학회지
• /
• 제8권1호
• /
• pp.1-5
• /
• 2010

Purpose : This research inquires into the effect of applying microcurrent (MC) according to various frequency levels on the pain and functional recovery of patients with chronic back pain. Methods : Thirty participants with chronic lower back pain disease were divided equally into three experimenta l groups. The MC frequency used in the first experimental group was 0.5Hz, the second experimental group was 50Hz, and the third experimental group was 100Hz for 20 minute sessions. A hot pack and ultrasound were applied to all groups as the general physical therapy. Measurements were taken using the visual analogue scale (VAS), the face pain rating scale (FPRS), and the Oswestry disability index (001). The analysis used the paired t-test in order to compare pretest and posttest results. A one-way ANOVA was performed to make comparisons with regards to frequency levels. Results : VAS, FPRS, and 001 showed significant pain decrease in all groups except for the 001 measurement in the 0.5 Hz group. There were no significant differences according to frequency levels. Conclusion: For chronic pain and functional recovery, a microcurrent produces an effect after treatment. However, results did not show a significant difference in change obtained from differing frequency levels.

• 한국정보통신학회논문지
• /
• 제13권6호
• /
• pp.1175-1180
• /
• 2009

차세대 무선랜 표준인 IEEE 802.11n에서는 MAC 계층에서의 처리율을 향상시키기 위해서 프레임 집약 (Frame Aggregation) 기법을 제안하고 있다. IEEE 802.11n의 프레임 집약 기법은 MSDU (MAC Service Data Unit) 단위의 집약 기법 (Aggregate MSDU: A-MSDU)와 MPDU (MAC Protocol Data Unit) 단위의 집약 기법 (Aggregate MPDU: A-MPDU)의 두 가지 기법을 제안하고 있다. 본 논문에서는 A-MSDU와 A-MPDU를 결합한 2단계 프레임 집약 (Two-Level Frame Aggregation) 기법의 성능을 분석한다. 성능 분석을 위해 마르코브 체인에 기반하여 2단계 프레임 집약 기법의 처리율을 모델링한 뒤 이를 이용하여 노드의 수와 채널 상태 등에 따른 프레임 집약 기법의 처리율 변화 추이를 분석한다. 그리고 분석 결과에 기반하여 최적의 프레임 집약 기법을 설계하기 위한 방법을 제시한다.

• 한국자동차공학회논문집
• /
• 제22권3호
• /
• pp.60-67
• /
• 2014

The battery cells in lithium-ion battery pack assembled with high-capacity and high-power pouch cells, are commonly cooled with thin aluminum cooling plates in contact with the cells. For HEV/EV lithium-ion battery systems assembled with high-capacity, high-power pouch cells, the cells are commonly cooled with thin aluminum cooling plates in contact with the cells. Thin aluminum cooling plates are cooled by cold plate with coolant flow paths. In this study, the effect of the battery cooling system design including aluminum cooling plate thickness and various position of cold plate on the cooling performance are investigated by using finite element methods (FEM). Optimal cooling plate and cold plate design are proposed for improving the uniformity in temperature distributions as well as lowering average temperature for the cells with large capacities based on the simulation results.

• 한국정밀공학회지
• /
• 제27권5호
• /
• pp.27-35
• /
• 2010

A loader used for uploading materials into truck is a kind of construction equipment. Mainly, a wheel loader is applied to construction work. Recently, an automatic transmission for the wheel loader is used to help drivers get the repetitive works done comfortably. It is composed of geartrain, clutch pack, hydraulic control system and TCU. Especially, a high-performance proportional control valve and its control algorithm is demanded to achieve the shift quality during a change of speed. In this paper, the commercial package program was used in order to justify model of the proportional control valve and simulate it. Steady-state and dynamic characteristics of PCV were analyzed to classify attractive forces and hydraulic control characteristics. This model also was verified the validity compared to the experimental result. Using the developed model, performances of PCV were predicted as studying design parameters.

• 한국시스템다이내믹스연구
• /
• 제1권1호
• /
• pp.159-183
• /
• 2000

How to protect the environment without sacrificing the human environment and economy at the level of region is on of the most difficult issues of recent times. The dynamic Interactions between economic activities and environmental pollution control activities determine whether social welfare is increased of decreased by such activities and provides a basis for saying whether they help or hurt the economy. Bureaucratic Approach of Local government has failed, and an Impetus has arisen to develop new tools of analysis, useful for finding policy leverages focused on sustainability. This paper focus on understanding dynamic relationships between regional economic system and environmental system, and presenting possible framework for finding policy leverages in dynamic interaction behaviors. The case, selected in this study, is Nacdong river regions case, which is related many meaningful issues about sustainable development： two big metropolitan government and dwellers have different opinion with regard to construction of large scale Industrial pack, drinking water supply, and environment model consisting of three sectors： regional economy sector, river pollution and drinking water sector, environmental protection and investment policy sector Finally, this paper deal with how to link policy leverage to causal loop structure for the sustainable development of two regions.