• Journal of information and communication convergence engineering
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• 제15권3호
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• pp.143-150
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• 2017

Absorption of microwave radio frequency signal by atmospheric rain is prevalent at frequencies above 10 GHz. This paper presents the studies on rain attenuation at 18 GHz for 3.2 km experimental link between Khumdang (Korea Telecom, KT station) and Icheon (National Radio Research Agency, RRA station). The received signal data for rain attenuation and rain rate were collected at 10 second intervals over a three year periods from 2013 to 2015. Out of several models, the paper present discussion and comparison of ITU-R P.530-16 model, Moupfouma model, Da Silva Mello model along with suitable rain attenuation prediction method. The limitation of research lies on the experimental system that is set up in only one location, however, the preliminary results indicate the application of suitable 1-minute rain attenuation model for specific site. The method provides useful information for microwave engineers and researchers in making decision over the choice of most suitable rain attenuation prediction in terrestrial links.

• 경영과정보연구
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• 제23권
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• pp.157-174
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• 2007

Concerning this nation's M&A system, it is expected that standards of limitation on ownership is considerably modified and alleviated. This would allow companies to freely merge with each other, raising the efficiency of the whole national economy and ultimately benefiting all economic subjects. Another goal of business merger lies in adjusting net income or reducing tax amount. The income and the amount are to be financially reported. If merger between companies does not create any synergy effect, but just contributes to net income increase or tax reduction for the purpose of the parties' financial reporting, it might distort a rational distribution of wealth over all facets of economy. Merger whose goal is to create the most desirable synergy effect should be positively encouraged, but that whose goal lies in tax avoidance needs to be strongly restricted. Thus the purpose of this study was to find how to improve this nation's merger-related taxation system. For the purpose, this researcher investigated problems of existing tax supports to merger, which meets related taxation requirements, especially in terms of liquidation income, appraisal profit from merger, fictitious dividend and requirements for taxation. Among the problems, the study found, the biggest thing was that liquidation income or deficit carried forward, if any, is subject to be prior deducted from surplus, so the income is likely to generate. To raise the consistency of this nation's taxation on business restructuring, existing local systems in regard to merger, division, investment in kind and dividend-exclusion method need to be reconsidered following the introduction of consolidated taxation system.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권1호
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• pp.23-29
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• 2005

This paper presents the characteristics of leakage currents flowing through ZinC Oxide(ZnO) surge arrester blocks under mixed direct and 60 Hz alternating voltages. A mixed voltage, in which an alternating voltage is superimposed upon a direct voltage, appears on the HVDC system network. The mixed direct and alternating voltage generator with a peak open-circuit of 10 kV was designed and fabricated. The leakage currents and V-I curves for the fine and used ZnO surge arrester blocks were measured as a function of the voltage ratio k, where the voltage ratio k is defined as the ratio of the peak of alternating voltage to the peak of the mixed voltages. The resistive component in the leakage current in the low conduction region is significantly increased with increasing the voltage ratio k. The V-I characteristic curves for the mixed voltages lies between the direct and alternating characteristics, and the cross-over phenomenon in the high conduction region was appeared.

• 한국조경학회지
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• 제35권3호
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• pp.22-36
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• 2007

The direction of this study lies in exploring a schematic proposal for a historical walk over an area called 'West Village' located inside the old city wall of Seoul. The case study area is comparable to the historic 'North Village,' including historical assets such as the Kyunghi Royal Palace and Sajik-dan. Moreover, it has spectacular scenic spots surrounding Mt. Inwang and Baegundong Stream, although this has now been paved over for use as a road. This village maintained its fame as a hub of art through the early 20th century. The comprehensive approach of this study ranges from the historical and cultural to the ecological and visual. The results of this study can be summarized as follows. A themed walk would commemorate the great leader of national independence, Baegbeom Kim Ku, as well as the famous Korean style realistic landscape painting school under the leadership of Kyumjae Jeong Seon, a great artist of the Josun Dynasty. In addition, a scenic streamside walk would accentuate the surrounding panoramic vistas which were drawn by Kyumjae, while at the same time allowing the ecological system of Baegundong Stream to be uncovered and restored.

• 한국주거학회논문집
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• 제4권2호
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• pp.1-9
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• 1993

This study is a basic research to analyze and estimate the light environment of the classroom by serial correlation of time. Its purpose lies in the comparison by time period in order In select floor for laboratory and to calculate the uniformity factor. The proving ground is T building in W university, Which is five floor of central hall type. The subject of investigating is eight classrooms, four rooms in South and North, from the second floor that is net influenced by the shelter. The results that compared and estimated them in the illumination of daylight, Uniformity factor, Daylight factor, are as follows1. The illumination of classroom in South and North is over 10001x, but the classroom in North is good and the classroom in South excellent.2. The uniformity factor of classroom in South is good and that of classroom in North is normal.3. The daylight factor of each classroom is over 5% but the classroom in South is above that in North. The classroom in South surpasses the classroom in North in the general light environment and the classroom in third and fourth floor is so better than that in second and fifth floor in the condition of laboratory In the uniformity factor, the classroom in fourth can be better than any classroom.

• Industrial Engineering and Management Systems
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• 제9권2호
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• pp.107-120
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• 2010

In today's uncertain economic environment, the evaluation of safety for investment alternatives is of practical importance in manufacturing companies. This paper examines a method of quantitatively evaluating profitability and risk for multiple alternatives using the total-cost unit-cost domain. The paper assumes such factors as unit sales price, sales and production volume, unit variable cost, fixed cost, and yield for each alternative. The paper incorporates the relationship between production capacity and demand, distinguishing between cases of production capacity surplus and shortage for each year over the entire planning horizon. The paper investigates the case in which the values of each factor independently move in the direction of decreasing profit each year, and clarifies the procedure of comparing safety among multiple investment alternatives on a single consolidated total-cost unit-cost domain. The difficulty of the problem lies in the method of consolidating multiple total-cost unit-cost domains into a single domain since the combination of years of capacity surplus and shortage depends upon the change values in each factor under consideration. A systematic method of evaluating profitability as well as risk is presented, and the validity of the proposed method is verified using a numerical example.

• 전기전자학회논문지
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• 제27권4호
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• pp.430-438
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• 2023

The Modular Multilevel Converter (MMC) has emerged as a key component in HVDC systems due to its ability to efficiently transmit large amounts of power over long distances. In such systems, accurate estimation of the MMC capacitor voltage is of utmost importance for ensuring optimal system performance, stability, and reliability. Traditional methods for voltage estimation may face limitations in accuracy and robustness, prompting the need for innovative approaches. In this paper, we propose a novel distributed neural network observer specifically designed for MMC capacitor voltage estimation. Our observer harnesses the power of a multi-layer neural network architecture, which enables the observer to learn and adapt to the complex dynamics of the MMC system. By utilizing a distributed approach, we deploy multiple observers, each with its own set of neural network layers, to collectively estimate the capacitor voltage. This distributed configuration enhances the accuracy and robustness of the voltage estimation process. A crucial aspect of our observer's performance lies in the meticulous initialization of random weights within the neural network. This initialization process ensures that the observer starts with a solid foundation for efficient learning and accurate voltage estimation. The observer iteratively updates its weights based on the observed voltage and current values, continuously improving its estimation accuracy over time. The validity of proposed algorithm is verified by the result of estimated voltage at each observer in capacitor of MMC.

• 인문언어
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• 제2권2호
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• pp.321-347
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• 2002

The Russian language uses more words that imply collectivism than Western Indo-European languages. In Korean, the first-person plural pronouns are used more often than in Western languages. In this respect, Russian seems to stand closer to the latter, although typologically it belongs to the Indo-European family. The predominance of 'we' over 'I,' which took place in the history of the Russian language, had something to do with the Russian commune and the ecclesiastical and spiritual concept of 'sobornost' (equation omitted). A similarity between the Russian and the Korean nations lies in a collective way of life as compared to Western nations. The Russian concepts of (equation omitted) and (equation omitted) ('commune') have direct analogues in the Korean language. In all societies a commune involves a certain sense of collectivity, or spiritual unity of the people - 'sobornost' (equation omitted). Korean collectivity is more familial and moral in character, whereas Russian 'sobornost' is more spiritual. This has its direct reflection in Korean and Russian languages. One can say that a sort of a family version of Russian 'sobornost' takes place in Korean society.

• 로봇학회논문지
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• 제6권4호
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• pp.317-322
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• 2011

An augmented state feedback controller for a Wheeled Inverted Pendulum (WIP) is proposed in this research. The augmented state feedback controller is able to keep the WIP returning to the origin. Generally, the WIP has both stable and unstable equilibrium points. To keep the WIP over the unstable equilibrium point, the WIP consistently is being controlled. A simple state feedback controller is letting the WIP out of the origin when the center of gravity of the WIP locates out of the schematic center line. In some case of applications, it may not be desirable that the WIP is drifting out of the initial location. The proposed augmented state feedback controller is able to keep the WIP at the initial location whether its center of gravity lies out of the center line or not. Numerical simulations are carried out to show the validation of the augmented sated feedback controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.299-302
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• 1996

A control algorithm is proposed for nonlinear multi-input multi-output(MIMO) batch processes by combining quadratic iterative learning control(Q-ILC) with model predictive control(MPC). Both controls are designed based on output feedback and Kalman filter is incorporated for state estimation. Novelty of the proposed algorithm lies in the facts that, unlike feedback-only control, unknown sustained disturbances which are repeated over batches can be completely rejected and asymptotically perfect tracking is possible for zero random disturbance case even with uncertain process model.