초경합금 소재 LCU_CL 코어의 초정밀 연삭 특성에 관한 연구

정상화,차경래,김현욱,이봉주 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

As the various manufacturing technology of optical glass is developed, the aspherical lenses are applied to many fields. However, It is still very difficult to manufacture glass lens because of the high cost and the short life of core. In recent years, the demands of the aspherical glass lenses increase since it is difficult to obtain the desirable performance in the plastic lens. In the glass mold lens, it has merits of high productivity and reproductivity since lens is manufactured by the only forming with high precision mold. The fabricating conditions for glass mold lens are glass surface that does not cause fusion, viscosity of 108-1013 poise for the 0.2㎛ accuracy, and viscoelasticity for the roughness less than 100 angstrom. In this thesis, ultra-precision grinding characteristics of tungsten carbide for forming the aspherical glass lens core were studied and the result of it is applied to manufacture the tungsten carbide-base core of the glass lens used to the laser scanning unit and the camera phone.

배추(Brassica campestris L. var. pekinensis Makino)의 cDNA library 구축 및 상동성 비교

안주미,권오병,전봉균,이풍연,이정민,권무식 성균관대학교 생명과학자원연구소 1995 生命資源科學硏究 Vol.2 No.1

Expressed sequence tag(EST) has a good value to discover a new gene or to study its structure. Some 20 ESTs were generated to obtain new genetic resources of chinese cabbage(Brassian campestris L. var. pekinensis Makino). Poly A+ RNAs were isolated from 10-day-old seedlings grown at 25℃ under the day light. cDNA gene bank was constructed using λ ZAP /cDNA synthesis /Giga Pack Gold Packing kit. About a million clones were able to obtain from the library. All the clones examined so far had insert DNAs. Nucleotide compositions of randomly selected clones were determined by the Sanger mthod. The DNA sequences were compared with those deposited in the GenePept and GenBank database to figure out nucleotide homologies. Two ESTs showed significant similarities to the enlisted sequences. They are chloroplast GADPH subunit of Arabidopsis thaliana and carbonic anhydrase of A. thaliana. The full DNA sequences of the two clones are being determined. The cDNA gene bank constructed. in this experiment will being used to isolate more genes induced by the light in the plant.

동진강 해역 표층 퇴적물 중 인의 화학적 형태별 함량

이현정,손재권,박봉주,조재영 한국농촌계획학회 2005 농촌계획 Vol.11 No.4

유연성을 갖는 분산 해쉬 테이블 기반의 피어 투 피어 인터넷 텔레포니 서비스의 구현

이주호,김재봉,정충교 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

Internet telephony provides voice communication services with added flexibility for multimedia extension at a lower cost compared to traditional telephone systems. We implemented an internet telephony system as an overlay network without a centralized server, using a distributed hash table (DHT). Compared to the current server-based internet telephony system, our system is fault-tolerant, scalable, and can be flexible extended to various services and advanced to integrated service. To demonstrate the high flexibility of our DHT-based internet telephony system, we made our system cooperate with web servers. Web users can check up others online states and establish voice communication sessions to online users at a mouse click. This technology can be tipplied to more complex services such as multimedia messaging or video conference service.

에어로빅 운동이 비만 여중생의 복부비만과 심폐기능 및 인슐린에 미치는 영향

김기봉,신주화,이정아 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.14 No.6

The purpose of this study was to analyze the effects of aerobic exercise on abdominal obesity, cardiopulmonary function and serum insulin in obese middle school girls participated in aerobic exercise for 20 weeks. The conclusions are as follows ; 1. Total body fat, percent body fat, body mass index, waist circumference and waist-hip ratio were significantly decreased, but lean body mass was significantly increased in the changes of body composition factors. 2. Systolic blood pressure, diastolic blood pressure were significantly decreased, but maximal oxygen consumption was significantly increased in the changes of cardiopulmonary function factors. 3. Total cholesterol, triglyceride, low-density lipoprotein cholesterol and insulin were significantly decreased, but high-density lipoprotein cholesterol was significantly increased in the changes of serum lipid and insulin factors. In conclusions, aerobic exercise may be very effective to decrease the obesity and geriatric diseases.

Supine Bicycle Ergometer 운동이 뇌파와 기분상태에 미치는 영향

윤진환,정일규,김영표,김종오,이희혁,오봉석,김창주 대한스포츠의학회 2003 대한스포츠의학회지 Vol.21 No.1

In this study we investigated the effects of supine ergometer exercise on physiological and psychological relaxation. Seven healthy young men(aged 24.4±2.00years) volunteered for the experiment. The experiment consisted of the following three successive segments" A pre-exercise period of 10 min, during which the subjects rested in a supine posture with their eyes closed for the final 5 min; an supine ergometer exercise period of approximately 10 min, during which the subjects performed intensity of 50%HRmax exercises; A post-exercise recovery of 5 min, and a recovery of 10 min, which was similar to the pre-exercise rest period. The electroencephalo-graphic(EEG) activity of the central cortex of the brain were measured pre-exercise, post-exercise 5 min, and recovery phase 10min. Fast Fourier Transformation of the EEG was used to obtain power spectrum areas in the delta(0.5~4 Hz), theta(4~8 Hz), alpha(8~13 Hz) and beta(13~30 Hz) frequencies. We compared the relative power values(power %) of the electroencephalogram alpha bands(8~13 Hz) and korean edition of the profile of mood states(K-POMS) before and after the supine ergometer exercise. We also estimated the percentage of maximal heart rate(%HRmax) throughout the experiment to ascertain the intensity of the supine bicycle ergometer exercise. The results of %HRmax indicated that the intensity of supine exercises practised in the experiments ranged from low to moderate. The power % of EEG alpha bands had increased significantly after the supine ergometer exercise compared with the pre-exercise rest(p<0.05). From the POMS results, we observed that positive mood(vigour) increased and negative mood(tension, depression, and total mood)decreased significantly after the supine ergometer exercise(p<0.05). This study found that the subjects showed increased physiological and psychological indices of relaxation after supine bicycle ergometer exercise.

연속생산공정에서의 유도형 유전알고리즘을 이용한 인과형 예측모델에 관한 연구

정호상,정봉주 한국경영과학회 2000 經營 科學 Vol.17 No.2

This paper presents a causal forecasting model using gulded genetic algorithm in continuous manufacturing process. The guided genetic algorithm(GGA) is an extended genetic algorithm(GA) using penalty function and population diversity index to increase forecasting accuracy. GGA adds to the canonical GA the concept of a penalty function to avoid selecting the unproductive chromosomes and to make a proper searching direction. Also, GGA modifies the current population using the similarity of chromosomes to avoid falling into the trap of local optimal solution. For investigating GGA performance, we used a set of real data that was collected in local glass melting processes, and experimental results show the proposed model results in the better forecasting accuracy than linear regression model and canonical GA.

글로벌 SCM 환경에서의 통합 생산계획 모델에 관한 연구

정호상,송익수,정봉주 한국로지스틱스학회 2002 로지스틱스연구 Vol.10 No.1

본 논문은 글로벌 SCM(Supply Chain Management) 환경에서 생산 연계 비용의 최소화를 목적으로 하는 생산 계획 수립 알고리즘을 제안한다. 글로벌 SCM환경은 지역적으로 분리된 여러 개의 공장에서 각각 부분품 및 완제품의 생산이 이루어지는 환경이다. 이러한 환경에서 완제품의 주문량 또는 수요 예측량을 만족하지 위해 제품의 BOM(Bill-Of-Material) 구조를 고려하여 각 부분품의 생산계획량을 결정해야 한다. 각 공장에서는 제한된 생산 능력을 가지면, 특정 부분품 또는 완제품을 생산한다. 부분품의 생산은 특정 공정 시간을 가지며 완성된 부분품은 이후 공정을 위해 다른 공장으로의 이동시간을 갖는다. 본 논문의 목적은 공장의 생산능력을 만족시키면서 제품의 공장별 생산 비용, 재고 비용, 공장 간 물류 비용을 최소화 시키는 생산 계획을 수립하는 문제의 해를 구하는 것이다. 본 논문에서는 글로벌 SCM 네트워크를 정의하고, 주어진 네트워크의 생산 계획문제를 혼합 정수 계획법을 이용하여 모델링한다. 효과적으로 문제를 해결하기 위해 계산 시간면에서 효율적인 발견적 기법을 제안하고 실험을 통해 해법의 성능을 검증한다. This paper presents a production planning algorithm for minimizing the costs of production and distribution in Global SCM(Supply Chain Management) environments. In the Global SCM environment, the several local plants produce parts and products. In this environment, we have to decide the production volumes of both parts and products considering the BOM(Bill-Of-Material) structure to meet the fixed order quantity or forecasted demand quantity. Each plant produces the specified parts of product and has a certain production capacity. There exist a fixed production lead time to make products and transportation lead time to move parts to different plants for subsequent processes. The objective of this study is to solve the production planning problem, which minimizes the total costs of production, inventory, and transportation under constraints of production capacity. For this problem, the integrated production planning model was formulated as a mixed integer programming, and an efficient heuristic algorithms was proposed. The experimental investigation shows that the proposed heuristic generates quite good solutions at very low computation costs.

전자 상거래에서 인터넷 쇼핑몰의 비즈니스 평가 모델

박용진,한주윤,정봉주 한국경영과학회 2000 經營 科學 Vol.17 No.3

This paper proposes an evaluation model for internet shopping mall business by defining its characteristics and evaluation criteria. We analyzed the characteristics of internet shopping mall business environments and classified the business into four major categories. We derived the evaluation criteria which can evaluate all categories comprehensively. The proposed criteria are cost, netizen, technology, transaction, and marketing, each of which gives a significant Impact on the business profitability. Based on these criteria, a quantitative evaluation method was developed. We also proposed a penta-classification scheme which can be used to identify the overall characteristic shape of each internet shopping mall business site. An actual application of our evaluation model was illustrated in order to show that our proposed model may be used in the real business sites.

공급 사슬 환경에서의 고객주문만족 시스템

장지홍,정호상,정봉주 연세대학교 산업기술연구소 2000 논문집 Vol.32 No.2

기업의 틀을 뛰어넘어 고객과 공급자까지 자사를 중심으로 통합하는 공급 사슬 환경에 있어서 고객 만족 수준을 향상시키는 것은 매우 중요하다. 고객 만족 수준을 높이기 위해서는 우선 정확한 수요예측을 통하여 주문에 대비해야 하며, 주문이 들어올 경우 고객에게 정확한 납기회신을 제공해야 한다. 물류, 정보, 자금 등의 흐름을 총괄하는 공급 사슬 환경의 특성상, 정확한 수요예측과 납기회신을 제공하기 위해서는 제품의 공급자, 고객을 포함한 공급 사슬내의 여러 파트너 들에 대한 종합적인 고려가 이루어져야 한다. 본 연구에서는 일반적인 공급 사슬 환경에서 사용 가능한 수요계획 시스템을 구축하는데 필요한 모델과, 고객의 주문에 대한 납기 제시를 위한 납기회신 알고리듬을 제시하고자 한다. : 공급사슬관리, 수요계획, 납기회신