• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.169-173
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• 2008

This study is concerned with adopting the hydroforming method in the front axle of the commercial vehicle. Generally the front axle of the commercial vehicle is made bγ the several operations of press forging. This product supports the big weight of the vehicle and load. The weight of the press forging parts is also so more than it of the press parts of the passenger car. So, we have studied the hydroforming method to lessen the weight of the front axle of the commercial vehicle. To apply the hydroforming method in the commercial vehicle, we had to use the operation of reducing the diameter of the used tube prior to the hydorforming operation.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권8호
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• pp.509-513
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• 2000

This paper deals with the parallel operation of space vector PWM for large capacity inverter system. To enlarge the capacity of inverter system and to reduce the current ripples on inverter output side, two or more inverters are operated in parallel. In this paper, a new parallel operation strategy which minimizes the harmonic distortion of the output stage is described. The proposed method is developed on the basis of the space-vector PWM in order to increase the linearly controllable voltage range. With the help of the proposed voltage synthesis method, the total harmonic distortion of the output stage can be greatly reduced in compared with that of conventional method with sinusoidal PWM or that of the single inverter operation case. The experimental results with reduced scale test show the feasibility of the proposed voltage synthesis method.

• 한국패션뷰티학회지
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• 제5권1호
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• pp.71-77
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• 2007

This study attempted to comparative analysis about the physical and morphological damage degrees of hair according to the bleaching methods by $H_2O_2$ concentration. As a result of the changes in the physical characteristics of the hair according to the deceleration operation methods by 3-6-9% and 9% $H_2O_2$ concentration, the intensity of tension considerably decreased but the elongation was increased. And the more the damage of hair, the larger the degree of change. Regarding the method of deceleration operation, the 3-6-9% deceleration operation method was more damaging than the 9% single deceleration operation method. In the change of the characteristics of the form of the hair, the control group of the 5-level deceleration hair generally showed a smooth external appearance and regular and closely overlapped epidermis and undamaged cuticle were observed. But in the 3-6-9% deceleration operation method and 9% single deceleration operation method, damages such as the irregular form of the edge of the epidermis and the unclear boundary between the epidermis occurred.

• Journal of information and communication convergence engineering
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• 제9권4호
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• pp.435-440
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• 2011

This paper propose the method of constructing the highly efficiency adder and multiplier systems over finite fields. The addition arithmetic operation over finite field is simple comparatively because that addition arithmetic operation is analyzed by each digit modP summation independently. But in case of multiplication arithmetic operation, we generate maximum k=2m-2 degree of ${\alpha}^k$ terms, therefore we decrease k into m-1 degree using irreducible primitive polynomial. We propose two method of control signal generation for the purpose of performing above decrease process. One method is the combinational logic expression and the other method is universal signal generation. The proposed method of constructing the highly adder/multiplier systems is as following. First of all, we obtain algorithms for addition and multiplication arithmetic operation based on the mathematical properties over finite fields, next we construct basic cell of A-cell and M-cell using T-gate and modP cyclic gate. Finally we construct adder module and multiplier module over finite fields after synthesizing ${\alpha}^k$ generation module and control signal CSt generation module with A-cell and M-cell. Next, we constructing the arithmetic operation unit over finite fields. Then, we propose the future research and prospects.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2010년도 추계학술대회
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• pp.110-111
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• 2010

최근 컨테이너 터미널의 관리자들은 안벽의 생산성을 높이기 위해서 양 적하를 동시에 할 수 있는 더블 사이클이나 듀얼 사이클을 시도하고 있다. 하지만 실제 터미널의 데이터를 이용하여 듀얼 사이클을 발생시켰을 경우 YT(Yard Tractor) 배정 방법이나, QC(Quay Crane)의 작업의 속도, 야드의 수출컨테이너 위치 등에 따라 효율성이 저하 될 수 있다. 따라서 본 논문에서는 실제 터미널에서 듀얼 사이클을 사용할 때 효율성을 더 높일 수 있는 터미널 운영방법을 제시한다.

• 융합정보논문지
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• 제11권4호
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• pp.203-210
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• 2021

본 연구는 의료기관의 설립운영 관리주체에 따라 운영자금 조달방법별 조달비율과 이들이 경영성과에 미치는 영향을 살펴보고자 의료기관 회계정보 공시시스템에 등록된 재무정보를 이용하여 분석하였다. 분석방법은 설립운영 관리주체별 차이비교를 위하여 분산분석을 실시하였으며, 운영자금 조달방법별 조달비율이 경영성과에 미치는 영향은 로지스틱 회귀분석과 회귀분석을 실시하였다. 연구결과, 운영자금 대비 총수익 비율은 설립운영 관리주체에 따라 유의한 차이가 있었다. 그리고 운영자금 조달방법별 조달비율은 경영결과(적자, 흑자)와 유의하게 인과관계가 있는 것으로 확인되었으며, 운영자금 조달방법 조달비율이 경영성과에 미치는 영향은 설립운영 관리주체에 따라 차이가 있었다. 이상의 결과 의료기관의 운전자금 관리는 운영자금에 대한 수익의 비율을 고려한 비용관리를 우선적으로 적용하고 그 다음으로 내부운영자금을 활용하는 방안의 적용이 적절할 것으로 사료된다.

• 한국멀티미디어학회논문지
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• 제17권7호
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• pp.858-865
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• 2014

In the case of system like MES, various sensors collect the data in real time and save it as a big data to monitor the process. However, if there is big data mining in distributed computing system, whole processing process can be improved. In this paper, system to analyze the cause of operation deviation was built using the big data which has been collected from deasphalting process at the two different plants. By applying multivariate statistical analysis to the big data which has been collected through MES(Manufacturing Execution System), main cause of operation deviation was analyzed. We present the example of analyzing the operation deviation of deasphalting process using the big data which collected from MES by using multivariate statistics analysis method. As a result of regression analysis of the forward stepwise method, regression equation has been found which can explain 52% increase of performance compare to existing model. Through this suggested method, the existing petrochemical process can be replaced which is manual analysis method and has the risk of being subjective according to the tester. The new method can provide the objective analysis method based on numbers and statistic.

• 한국산업융합학회 논문집
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• 제26권6_2호
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• pp.1097-1108
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• 2023

Recently, demand for technology for energy economy and stable supply is increasing due to the increase in power demand of loads. The amount of DC power generation using new and renewable energy is noticeably increasing, and the use of DC power supplies is also increasing due to the increase in electric vehicles and digital loads. During parallel operation to increase the capacity of the power converter, the module bus method or the method using Can communication and serial communication has significant difficulties in smooth operation due to communication time delay for information sharing. Synchronization of information sharing of each power converter is essential for smooth parallel operation, and minimization of communication time delay is urgently needed as a way to overcome this problem. In this paper, a new communication method using pulse width information is proposed as a communication method specialized for parallel operation of power converters to compensate for the disadvantage of communication transmission delay in the existing system. The proposed communication method has the advantage of being easily implemented using the PWM and Capture function of the microcomputer. In addition, the DC/DC converter for DC distribution was verified through simulation and experiment, and it has the advantage of easy capacity expansion when applied to parallel operation of various types of power converters as well as DC/DC converters.

• 한국컴퓨터정보학회논문지
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• 제28권10호
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• pp.267-275
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• 2023

조선 및 해운·물류 분야의 디지털 전환은 자율운항선박의 도입 및 선박의 운항방식의 변화를 이끌 것으로 예상된다. 기존 운항방식과 함께 자율운항, 원격운항 등 다양한 운항형태가 공존하며, 선박 운용 프로세스의 전환과 새로운 이해관계자의 등장이 전망된다. 본 논문에서는 선박 운항방식 변화에 따른 미래 선박 운항 프로세스를 분석하고, 미래 선박의 운항환경 변화를 예측하여 주요 업무별·이해관계자별 기능요건을 도출하고자 한다. 델파이 기법을 활용하여 항해 및 화물운송 계획 수립단계부터 최종 목적항 입항 및 화물 하역단계까지 선박 운항 시나리오를 구성하고, 업무별, 수행 주체별 미래 업무 변화를 예측했다. 원격운항, 자율운항 등으로 선원의 개입이 최소화될 것이며, 각 분야의 전문가가 선박 운항의 다양한 측면에서 책임과 의무를 갖게 될 것으로 예상된다.

• 상하수도학회지
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• 제32권5호
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• pp.421-434
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• 2018

Water supply/intake pumps operation use 70~80% of power costs in water treatment plants. In the water treatment plant, seasonal and hourly differential electricity rates are applied, so proper pump scheduling can yield power cost savings. Accordingly, the purpose of this study was to develop an optimal water supply pump scheduling scheme. An optimal operation method of water supply pumps by using genetic algorithm was developed. Also, a method to minimize power cost for water supply pump operation based on pump performance derived from the thermodynamic pump efficiency measurement method was proposed. Water level constraints to provide sufficient disinfection performance in a clearwell and reservoirs were calibrated. In addition, continuous operation time constraints were calibrated to prevent frequent pump switching. As a result of optimization, savings ratios during 7 days in winter and summer were 4.5% and 5.1%, respectively. In this study, the method for optimal water pump operation was developed to secure disinfection performance in the clearwell and to save power cost. It is expected that it will be used as a more advanced optimal water pump operation method through further studies such as water demand forecasting and efficiency according to pump combination.