발열체의 열손실 분석에 의한 새로운 풍속측정 방법에 관한 연구

조성철 청주대학교 2020 국내석사

본 논문에서는 발열체의 열손실 분석에 의한 새로운 풍속 측정 방법을 제안하였다. 풍속 측정 시스템은 전기히터, 방열판, 그리고 온도계로 구성(방열판 양쪽에 전기 히터와 온도계를 부착함)되는 풍속센서와 지름이 100mm인 원통형 파이프로 구성된다. 측정원리는 공기의 흐름에 따라 가열된 전기히터의 온도 차이를 이용하여 공기의 흐름 속도 즉, 풍속을 측정하는 것이다. 실험결과 A형(25mm) 방열판을 사용한 경우, 풍속 측정 범위는 0.0 ~ 2.09m/sec이였고 이때 온도범위는 80℃~35.2℃이였다. B형(45mm) 방열판을 사용한 경우, 풍속 측정 범위는 0.0 ~ 2.09m/sec이였고 이때 온도범위는 74.2℃~31.7℃이였다. 최초 측정을 위해 전기히터의 가열시간이 필요한데 A형과 B형은 각각 14분 23초와 17분 04초가 소요되었다. 2가지의 실험결과 풍속의 측정범위가 0.0 ~ 0.2m/sec에서는 우수한 온도 감도를 갖고 있다는 것을 알 수 있으며, 이론과 같이 온도에 대한 풍속은 자연지수 형태로 감소한다는 것을 알 수 있었다. 본 연구에서 증명한 발열체의 열손실을 이용한 풍속 측정 방법은 큰 의미가 있으며 상품화할 경우 저속의 풍속 측정이 가능하므로 정밀 환경제어 시스템에 적용이 가능할 것으로 판단된다. In this paper, a new wind speed measurement method using heat loss analysis of heating elements is proposed. The wind speed measurement system consists of a wind speed sensor consisting of an electric heater, a heat sink and a thermometer(attaching an electric heater and a thermometer on both sides of the heat sink) and a cylindrical pipe having a diameter of 100 mm. The measuring principle is to measure the air flow rate, that is, the wind speed, by using the temperature difference of the heated electric heater according to the air flow. As a result of the test, when the A-type (25mm) heat sink was used, the wind speed measurement range was 0.0 to 2.09m/sec, and the temperature range was 80℃ to 35.2℃. In the case of using a type B (45 mm) heat sink, the wind speed measurement range was 0.0 to 2.09m/sec, and the temperature range was 74.2℃C. to 31.7℃. For the initial measurement, the heating time of the electric heater was required. Type A and B took 14 minutes 23 seconds and 17 minutes 04 seconds, respectively. As a result of the two experiments, it can be seen that the measurement range of the wind speed has excellent temperature sensitivity at 0.0 ~ 0.2m/sec. The wind speed measurement method using the heat loss of the heating element proved in this study has great meaning, and if it is commercialized, it can be applied to the precision environment control system because the low speed wind speed can be measured.

자율학습기반의 에너지 효율적인 서버 클러스터 관리 기법

조성철 숭실대학교 대학원 2015 국내박사

에너지 절감형 서버 클러스터에서는 에너지 절감을 고려하지 않는 기존 서버 클러스터에 비해 서비스 품질을 보장하면서 전력소비를 절감하는 것을 목표로 한다. 현재의 부하를 처리하는데 필요한 최소수의 서버들만 ON 하도록 고정 주기 또는 가변 주기로 서버들의 전원 모드를 조정한다. 이에 대한 기존 연구들은 전력절감 또는 열을 낮추는데 노력해왔지만 에너지 효율성을 잘 고려하지 못했다. 본 논문에서는 에너지 효율 지수인 단위전력 당 성능과 QoS 측면에서 향상을 목표로 에너지 효율적인 클러스터 관리기법을 제안한다. 첫째 제안방법은 자율학습기반의 서버 전원 모드 제어이다. 이 전원모드 제어는 워크로드 유형을 사전에 정의한대로 분류를 하고, 이전에 학습이 수행되었는지 확인한다. 이미 수행되었다면 기록된 파라미터를 이용한다. 그렇지 않다면 학습을 수행하여 에너지 효율성 관점에서 최고의 파라미터를 얻어 저장한다. 이러한 과정에서 얻어진 최적화된 파라미터를 이용하여 서버전원 모드를 조정한다. 둘째 제안방법은 급격한 변화의 부하 트래픽을 다루기 위한 예측기반의 서버 전원 모드 제어이다. 예측기반의 전원 모드 제어는 기존 시계열 분석에 기반한 예측과 추세를 반영한 예측 조정의 두 부분으로 구성된다. 4가지 유형의 기존의 시계열 예측 모델과 4가지 유형의 수정된 모델에 대해 성능을 비교한다. 일정 부하 상황에서 주어진 시간 동안의 총 소비전력과 사용자 요청을 측정해 계수를 얻고, 계수와 추세 조정된 예측 사용자 요청을 곱하여 예측된 서버 소비전력을 구한다. 셋째 제안방법은 단위전력 당 성능과 QoS를 높이기 위해 자율학습방법과 전력소모 예측 방법을 결합한 서버 전원 모드 제어이다. 일반적인 부하 상황에서는 다중임계 학습기반의 서버 전원 모드 제어가 적용하고, 급변하는 부하 상황에서는 예측기반의 서버 전원모드 제어가 적용된다. 일반적 상황과 급변하는 상황의 구별은 현재의 사용자 요청과 관찰된 과거 몇 분의 사용자 요청의 비율에 따라 이루어진다. 또한, 동적종료 기법을 추가로 적용해 서버가 OFF하는데 소요되는 시간을 단축한다. 제안방법은 16대 서버로 구성된 클러스터 환경에서 3가지 부하 패턴을 이용하여 실험을 수행한다. 셋째 제안방법이 단위전력 당 성능(유효응답 수)과 표준화된 QoS측면에서 가장 우수한 결과를 보여준다. 이 방법의 실험결과를 정적 서버 모드 제어 실험결과와 비교할 때 뱅킹 부하패턴, 실제 부하패턴, 가상 부하패턴에서 단위전력 당 유효응답 수가 각각 5.35%, 11.64%, 49.92% 향상되고, QoS관점에서는 각각 2.89%, 6.81%, 50.92% 향상되었다. 또한, 이 방법의 실험결과를 파라미터 로드된 단일임계 학습의 실험결과와 비교할 때 뱅킹 부하패턴, 실제 부하패턴, 가상 부하패턴에서 단위전력 당 유효응답 수가 각각 1.66%, 2.9%, 3.84% 향상되고, QoS관점에서는 각각 0.45%, 1.33%, 8.82% 향상되었다 Energy aware server clusters aim to reduce power consumption at maximum while keeping QoS(quality of service) compared to energy non-aware server clusters. They adjust the power mode of each server in a fixed or variable time interval to activate only the minimum number of servers needed to handle current user requests. Previous studies on energy aware server cluster put efforts to reduce power consumption or heat dissipation, but they do not consider energy efficiency well. In this paper, we propose energy efficient cluster management methods to improve not only performance per watt but also QoS. Our first proposed method is to adjust server power mode based on autonomous learning. Firstly, according to the current load and traffic pattern, it classifies current workload pattern type in a predetermined way. Secondly, it searches learning table to check whether learning has been performed for the classified workload pattern type in the past. If yes, it uses the already-stored parameters. Otherwise, it performs learning for the classified workload pattern type to find the best parameters in terms of energy efficiency and stores the parameters. Thirdly, it adjusts server power mode with the optimized parameters. Our second proposed method is to adjust server power mode based on workload prediction to deal with rapidly changing loads. The proposed prediction algorithm consists of two parts: prediction based on the conventional time series analysis and prediction adjustment based on trend analysis. We compared performance for 4 types of conventional time series based prediction methods and their modified methods with our prediction algorithm. Given a workload situation, we calculate coefficient by dividing the total power consumption in a time interval by the number of user requests, and multiply it by the number of user requests with prediction adjustment to obtain the predicted amount of power consumption. Our third proposed method to improve not only performance per watt but also QoS is to adjust server power mode based on a hybrid approach of autonomous learning method and power consumption prediction method. Autonomous learning method with multi level thresholds is applied under normal load situation whereas power consumption prediction method is applied under abnormal load situation. The decision on whether current load is normal or abnormal depends on the ratio of the number of current user requests over the average number of user requests during recent past few minutes. Also, a dynamic shutdown method is additionally applied to shorten the time delay to make servers off. We implemented the proposed methods and performed experiments with a cluster of 16 servers using three different kinds of load patterns. Our third proposed method shows the best result in terms of normalized QoS and performance per watt (valid responses). Experimental results show that the third proposed method is better than the existing methods in terms of QoS and energy efficiency: for banking load pattern, real load pattern, and virtual load pattern, the numbers of good response per watt in the proposed method increase by 5.35%, 11.64% and 49.92%, respectively, whereas QoSs in the proposed method increase by 2.89%, 6.81% and 50.92%, respectively, compared to those in the existing static power mode control method. Also, the numbers of good response per watt in the proposed method increase by 1.66%, 2.9% and 3.84%, respectively, whereas QoSs in the proposed method increase by 0.45%, 1.33% and 8.82%, respectively, compared to those in the autonomous learning method with single level threshold.

선박 저속운항에 따른 선박 대기오염 물질 배출 영향에 관한 연구

조성철 한국해양대학교 대학원 2020 국내석사

Recently, with increasing interest in environmental, human and social hazards caused by air pollution, regulations are being strengthened to prevent air pollution, and IMO is also working to reduce air pollutants from ships. Efforts to reduce air pollutant emissions from ships include not only tightening regulations, but also countries and ports implementing incentives based on voluntary participation of ships, such as use of onshore power supply, vessel speed reduction or use of low sulfur fuel oil. Recently, air pollutants generated from ships are attracting attention as a major cause of national air pollution as well as in ports and communities near the ports where ships enter and leave frequently. The "special act on air quality improvement, including port areas" was enacted and is expected to be implemented on January 1, 2020. It is important to reinforce regulations of ships, but also I think it is necessary to study and review incentive system based on overseas cases. This study examines international and regional air pollution regulations for NOx, SOx, GHG, PM, etc and national incentive systems. And examines changes in ship emissions through Vessel Speed ​​Reduction among incentives to reduce air pollutants. The actual cases were examined and their impact was evaluated. The ultimate goal of this study is to look at ways to minimize and effectively manage errors prior to decision making and enforcement of these management systems by focusing on emission reductions at vessel speed reduction. First, the types of incentive schemes implemented by ports and their benefits were examined. Environmental Ship Index implemented by the International Association of ports and harbors applied to over 70 ports worldwide, Greenport Program in Singapore, Vessel Speed Reduction Program in various US ports, and Eco-ship in Panama. For the sake of confirmation the effectiveness of VSR among several incentive schemes, the speed reduction operation of case vessels was conducted arbitrarily on the actual operating vessel, and the data was reviewed on a case-by-case basis. However, the case-by-case analysis was different. In the case of relatively short distances, it was not possible to confirm the change in fuel consumption according to the change of ship speed. On the other hand, in the case of relatively long distances, constant changes in fuel consumption and air pollutant emissions were observed while the ship speed was changing. In light of this, the actual effect of VSR needs to be measured over a distance of 20 nautical miles. In addition, the ship's automatic identification system (AIS) data was obtained for vessels entering and leaving Busan port from February to May 2019 to examine the characteristics of each vessel. In order to analyze the air pollutant emission pattern, the fuel consumption was estimated and the emission was calculated when operating at the average speed of each ship type and reduced speed of the ship with Busan port data. As a result, the emission reduction efficiency according to the low speed operation of the ship was confirmed on the all vessels and the largest reduction effect in the container ship, and relatively small in the general cargo ship. However, when the ship's speed reduction program is applied, the operation time is extended due to the limitation of the ship's speed. The results showed little change. This seems to be because the ship's emissions are compared with the estimated value proportionally, and therefore, it is necessary to collect and review the data of the actual operating ship. In addition, it is necessary for the government who make the policy decision about the VSR management system to conduct vessel speed reduction at sufficient distance from the land in consideration of the results of this study.

컴퓨터를 이용한 기어 설계 시스템 개발에 관한 연구

조성철 충남대학교 1998 국내박사

유료노인복지시설 프로그램 개발에 관한 연구

조성철 대구대학교 사회개발대학원 1999 국내석사

地籍不附合地整理 事例分析을 통한 整理方向에 관한 硏究

조성철 한성대학교 2007 국내석사

abstract: p. 69-70

생명보험상품의 수요결정요인에 관한 연구 : 경남지역을 대상으로

조성철 창원대학교 2008 국내석사

Life insurance industry which is one of momentous axis in finance industry must prepare multilateral reform plans for development of finance industry under the rapidly changing situation. One of the most important section which we must consider in reform plans is insurance consumer, because Insurance consumer purchase not only insurance but also image added it. As far as insurance company give service based price only, they cannot satisfy consumers in full. So, insurance company must provide worth that consumer really want. Consumer preferences can be changed on influence for the growth of economy, increase and decrease of an unemployment ratio, rise of aging and drop of birth rate, low interest. And life insurance demand may be influenced on the price of insurance policy, consumer's income, consumer's preference, the presence of related alternation and so on. This article analyzed existing research material to find out what influence this change give on of life insurance demand. Also, it investigated the actual situation on life insurance joining among a company employee and CEO, business owner, farmer, a farmer with a side job, public official, professional(pharmacist, doctor, lawyer), house-keeper more than 20 years old in Gyeongnam including Masan and Changwon. It categorized life insurance Demand based on age, income, reservation, the number of children, examined how much influence made by marriage, sex, occupation variable, indicated the differences of Kyeongnam and whole country. And it carried out survey and statistical analysis on the assumption that it can be exist determining factor on life insurance demand excepting consumer's income. In a consequence, it confirmed that the research is not distinct from existing insurance demand research, experience data, life consumer survey made by Insurance Development Institute. However, obsolete sale behavior of life insurance provider and seller is not effective no longer in a market, because life insurance subscriber and potential user will purchase reasonably due to improvement of information acquisition power from rapid change of finance market situation and improvement of media than in the past.

일반화된 공간 L(f)에 관한 연구

조성철 경북대학교 1986 국내석사

S. Simons은 參考文獻〔4〕에서 空間 1(Pν) 에 關한 여러 가지 性質들을 硏究하였다. 本 論文에서는 S. Simons의 硏究 結果들을 一般化된 函數 module를 定義하여 空間 L(f)를 一般化한 L_Γ(F)에 대한 多樣한 관계들을 調査하였다.

롤러 체인 시스템 시뮬레이션 위한 등속구간에서의 암시적 적분 방법 연구

조성철 한양대학교 대학원 2018 국내석사

체인 시스템의 다 물체 동역학 해석에서 암시적 적분 방법을 사용 시 해석 속도가 매우 느리고 그 중 자코비안 계산과 LU분해가 해석 시간의 대부분을 차지하고 있다. 본 논문에서는 체인 시스템의 등속구간에서의 운동 특성을 고려한 암시적 적분 방법을 제안한다. 구조 동역학 상용 프로그램인 DAFUL을 사용하여 체인 시스템을 모델링 하였으며 시스템을 4개의 구역으로 나누어 운동 특성을 조사했다. 운동 특성이 크게 변하는 구간만 부분적으로 자코비안을 업데이트하고 나머지 운동 특성이 작게 변하는 구역은 초기 등속 구간에서 한번만 계산하여 재사용하는 방법을 사용한다. 등속 구간에서 기존 Conventional method와 Proposed method 의 결과를 비교하였고 결과의 정확성은 거의 잃지 않으면서 해석 속도를 크게 향상 시켰다.

WEB 기반의 자기주도적 학습방법을 적용한 미술감상교육에 관한 연구 : 초등학교 5,6학년 감상 지도방안을 중심으로

조성철 경인교육대학교 교육대학원 2004 국내석사