• Structural Engineering and Mechanics
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• 제12권5호
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• pp.527-540
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• 2001

A new sort of learning algorithm named whole learning algorithm is proposed to simulate the nonlinear and dynamic behavior of RC members for the estimation of structural integrity. A mathematical technique to solve the multi-objective optimization problem is applied for the learning of the feedforward neural network, which is formulated so as to minimize the Euclidean norm of the error vector defined as the difference between the outputs and the target values for all the learning data sets. The change of the outputs is approximated in the first-order with respect to the amount of weight modification of the network. The governing equation for weight modification to make the error vector null is constituted with the consideration of the approximated outputs for all the learning data sets. The solution is neatly determined by means of the Moore-Penrose generalized inverse after summarization of the governing equation into the linear simultaneous equations with a rectangular matrix of coefficients. The learning efficiency of the proposed algorithm from the viewpoint of computational cost is verified in three types of problems to learn the truth table for exclusive or, the stress-strain relationship described by the Ramberg-Osgood model and the nonlinear and dynamic behavior of RC members observed under an earthquake.

• 정보보호학회논문지
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• 제30권5호
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• pp.823-834
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• 2020

과거 카드3사 개인정보유출 사건을 계기로 전산 프로그램 개발 시에도 운영환경과 동일 수준의 엄격한 전자금융감독규정을 준수하고 있다. 하지만, 전산 프로그램 개발시 해당 응용 프로그램과 연관된 테스트 데이터 변환 대상범위 식별이 불명확하여 테스트 데이터의 무결성이 훼손된 상태로 응용 프로그램을 검증하고 있어, 이 단계에서 발견되지 못한 결함이 서비스 장애로 이어지는 IT운영리스크가 증가되고 있다. 따라서, 본 논문에서는 특정 응용 프로그램과 연관된 테스트 데이터 변환대상 범위 선정을 위한 프로세스와 알고리즘을 제시하여 실증하였다.

• Journal of Biosystems Engineering
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• 제25권5호
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• pp.351-358
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• 2000

This study was conducted to develop a speed control system of a DC motor which drove a barley seeder mounted on a combine harvester. Barley seeder mounted on a combine has been known to reduce labor and cost of barley cultivation. However, development of the seeder has been unsuccessful because the combine, a dedicated rice and barley harvester has not enough space and proper power take-off for barley seeder. To develop a barley seeder, small powered motor speed controller was required. A proximity sensor for detecting working speed of the combine and a programmable one board microprocessor was used to develope a control system. Motor parameters and motor constant, relationship between seeding rate, motor speed, groove volumes of a tested roller, torque were measured. The proximity sensor sent a frequency signal to the microprocessor. In laboratory experiments, the excitation voltage of the motor was shown not to be proportional to the size of pulse width (duty ratio). A table transforming frequency signal, that represented for working speed to proper pulse width was developed from seeding rate experiments. However, seeding rate at low frequency signal was not proportional to the working speed. Seeding rate control proportional to the frequency signal was achieved by shifting of the frequency signal.

• 한국농공학회지
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• 제23권3호
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• pp.88-95
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• 1981

This study was carried out to investigate the relation between seepage losses and flow section area in earth canals. Totally 77 seepage measurement was gained by ponded method and the tested canals belong to the irrigation area of Farmland Improvement Association in each province, Korea. The results obtained from this study may be used as a reasonable criteria for the estimation of canal seepage losses in the design of irrigation systems. Obtained results are summarized as follows: 1. Average seepage rates in each Soils is 14cm/day in ML, 6. 3cm/day in CL and 24.9 cm/day in SM. 2. Water depth and water surface width in eath canals have little influenced on the seepage rate, while the seepage losses was increased in proportion as the water surface width lengthens. 3. A formula of S=C.An defining a relationship between seepage losses and flow section was derieved as follows. ML:S=O. 35 VA 1.20 (m$^3$/day/m) CL:S=O. 13 VA 0.84 SM:s=O.67VA-1.56 4. The average seepage loss rates per 1km of canal are as followings. Measured Time ML CL SM 0-4 hrs 2.2% 0.6% 4.5% 4-2 4hrs 1.0% 0.15% 2.0% In above table we may obtain the following results. The first row is suitable for the canal having short delivery time of irrigation, while the second row for the canal having long delivery time.

• 한국조경학회지
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• 제22권1호
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• pp.27-51
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• 1994

The purpose of this study was to suggest basic natural park planning guidelines which have to be considered before conservation plan. For this purpose, land potentiality was analyzed in the regional context. Natural parks in Tokyo Province were chosen as study areas because park systems in Japan and Korea are similar and lots of information are available in Japan. Land capabilities of study areas were analyzed, then the results were utilized to discuss how the natural parks. Land potentiality was analyzed by the degree of location quotient of land use allowance in homogeneous bio-physical land units, then comprehensive potentiality of bio-physical land units was revealed from existing and historical land use allowance. These 2 allowances, also, were utilized to find the limit of land use intensity, and the results were used for qualitative identification of the land potentiality and the land capability. As a results, the land use allowance and characteristics of 6 groups were identified as shown in Table 3 and Figure 6. Qualitative analysis of land potentiality in this study enabled to disscus the conservation and/or preservation of natural parks, based upon elements of land, and the guidelines of natural park conservation policy were suggested from the characteristics of land potentiality and regional relationship. This discussed land potentiality, and existing natural resources which were stressed from conservational view point need to be combined for comprhensive understanding of land resources.

• 한국인구학
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• 제2권1호
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• pp.5-16
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• 1978

The main purpose of this study is to examine the recent level of fertility and potentiality of the Korean population in Japan and to investigate some forces which influence the fertility of them using survey data. Some estimates of the level of fertility for the Korean population in Japan in 1974 are presented in Table 1. Comparing the some estimates for 1974 with those for 1969, the level of fertility in 1974 was realistically declined. It also indicated that potentiality of Koreans in Japan showed decreasing population. For investigating some factors affecting fertility, total births is selected which regressed on some variables believed in general to be influential in determiaing fertility. It was used a step-wise multiple regression to determine the independent as well as the combined effects of each of the variables. The SPSS computer program was used to perform the anlysis. Result from this data reveals that wife's family size preference as relevant predictor does influence the fertility of Koreans in Japan at this point considering that the age group of 20-29 is very much related. By employing multiple classification analysis, the analysis is concluded by nothing that the wi 3 family size preference has an even stronger relationship with economic factors than any other facto 3.

• 한국문헌정보학회지
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• 제43권3호
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• pp.379-397
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• 2009

이 연구는 DDC의 주된 성공요인중의 하나인 DDC 간략판에 대한 변천과정 및 특성을 분석하는데 목적이 있다. 이를 위해 DDC 완전판과 간략판에 대한 전체적인 관련성을 바탕으로 두 판간의 발행년도 및 물리적인 특성을 포함한 비교표를 제시하였으며, 초판부터 최근판인 제14판에 이르기까지 판별 전개내용과 특성을 분석하였다. 또한 DDC 간략판에서 사용되고 있는 4개 보조표의 도입 시기 및 변천과정을 살펴보았다.

• 산업경영시스템학회지
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• 제42권2호
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• pp.78-85
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• 2019

High variance observed in the measurement system can cause high process variation that can affect process capability badly. Therefore, measurement system analysis is closely related to process capability analysis. Generally, the evaluation for measurement system and process variance is performed separately in the industry. That is, the measurement system analysis is implemented before process monitoring, process capability and process performance analysis even though these analyses are closely related. This paper presents the effective concurrent evaluation procedure for measurement system analysis and process capability analysis using the table that contains Process Performance (Pp), Gage Repeatability & Reproducibility (%R&R) and Number of Distinct Categories (NDC). Furthermore, the long-term process capability index (Pp), which takes into account both gage variance and process variance, is used instead of the short-term process capability (Cp) considering only process variance. The long-term capability index can reflect well the relationship between the measurement system and process capability. The quality measurement and improvement guidelines by region scale are also described in detail. In conclusion, this research proposes the procedure that can execute the measurement system analysis and process capability analysis at the same time. The proposed procedure can contribute to reduction of the measurement staff's effort and to improvement of accurate evaluation.

• 전력전자학회논문지
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• 제26권5호
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• pp.364-371
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• 2021

A magnetic flux saturation model of Synchronous Reluctance Motors (SynRMs) and a parameter estimation method are proposed at standstill. The proposed magnetic flux model includes the nonlinear relationship between the current and the magnetic flux for self-saturation and cross-saturation. Voltage is injected at standstill to estimate the magnetic flux saturation model. Voltages are injected into the d-axis and q-axis to obtain data on self-saturation. Subsequently, voltages are simultaneously injected into the d-q axis to obtain data on cross-saturation. On the basis of the measured current and the calculated magnetic flux, the parameters of the proposed model are estimated using the least square method (LSM). Simulation and experiment were performed on a 1.5-kW SynRM to verify the proposed method. The proposed model can be used to create a high-efficiency operation table, a sensorless algorithm, and a current controller to improve the control performance of a motor.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.295-304
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• 2021

This study aims to identify and analyze the impact of internal factors on business efficiency of steel firms in Vietnam. The article uses data collected from the financial statements of 26 steel firms operating in Vietnam between 2012 and 2019. With the application of E-view software in quantitative analysis to build regression models on the table data (panel data), and the study has built a regression model identifying the relationship and impact level of internal factors affecting business efficiency of steel firms in Vietnam. In the study, the dependent variable is business efficiency, determined by the profit after tax on the firm's assets. The independent variables are firm size, growth rate, capital structure, ratio of long-term assets, receivables management, and solvency. The research results show that the four factors of firm size, growth rate of assets, receivables management, and solvency have a positive impact on business efficiency, while two factors including capital structure and ratio of long-term assets do not affect business efficiency of enterprises. The results of this article are very useful for corporate executives in general and for financial managers in particular, helping managers make the right financial decisions for the company to promote business efficiency of the company.