• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.89-94
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• 2008

The injection molding process is a predominant method for producing plastic parts. In order to maximize productivity and molding quality in a injection mold, it is important that each cavity in a multi-cavity injection mold is identical. This requires that cavity dimensions should be identical and delivery system of melt to each cavity have to be the same. Despite the geometrically balanced layout in multi-cavity injection mold more than 4 cavities, it has been observed that the filling in each cavity results in imbalances. Most of cases, this phenomenon of filling imbalances have a bad effect on dimension accuracy, warpage, molding appearance and strength of molding parts. In this study, experiment were conducted to investigate the effect of filling imbalances on the molding quality(surface gloss, shrinkage, tensile strength) in the multy-cavity injection mold.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.1966-1968
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• 1998

This paper describes a gate drive circuit for series connected IGBTs in high voltage applications. The proposed control criterion of the gate circuit is to actively limit the voltages during switching transients, while minimizing switching transient and losses. In order to achieve the control criterion, an analog closed loop control scheme is adopted. The performance of gate drive circuit is examined experimentally by the series connection of three IGBTs with conventional snubber circuits. The experimental results show the voltage balancing by an active control under wide variation in loads and imbalance conditions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.435-436
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• 2006

When working with multi-view images, imbalances between multi-view images occur a serious problem in multi-view video coding because they decrease the performance of disparity estimation. To overcome this problem, we propose inter-view balanced disparity estimation for multi-view video coding. In general, the imbalance problem can be solved by a preprocessing step that transforms reference images linearly. However, there are some problems in pre-processing such as the transformation of the original images. In order to obtain a balancing effect among the views, we perform block-based disparity estimation, which includes several balancing parameters.

• Journal of information and communication convergence engineering
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• 제11권4호
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• pp.268-273
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• 2013

In this paper, we propose a document classification model using Web documents as a part of the training corpus in order to resolve the imbalance of the training corpus size per category. For the purpose of retrieving the Web documents closely related to each category, the proposed document classification model calculates the matching score between word features and each category, and generates a Web search query by combining the higher-ranked word features and the category title. Then, the proposed document classification model sends each combined query to the open application programming interface of the Web search engine, and receives the snippet results retrieved from the Web search engine. Finally, the proposed document classification model adds these snippet results as Web documents to the training corpus. Experimental results show that the method that considers the balance of the training corpus size per category exhibits better performance in some categories with small training sets.

• 교육녹색환경연구
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• 제13권3호
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• pp.23-34
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• 2014

In order to keep the school's environment safe and clean, it needs to have a regular control system. There are limits to the student's abilities on keeping the school safe and clean, therefore cleaning professionals and specialized companies are needed as well. In case of financial program, principals or chief administrations are in charge of school building's environmental management. And it might cause poor efficiency and imbalance of distributing works on business in their charge and there are limits to keep the school's environment. This paper prepares alternatives of effective school building managements to solve these problems.

• 전기학회논문지
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• 제58권9호
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• pp.1706-1713
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• 2009

In this paper, a parallel operation algorithm for high power PEMFC generation systems is proposed. According to increasing the capacity of fuel cell systems with several fuel cell stacks, the different dynamic characteristics of each fuel cell stack effect on imbalance of load sharing and current distribution, so that a robust parallel operation algorithm is desired. Therefore, a power-sharing technique is developed and explained in order to design an optimal distributed PEMFC generation system. In addition, an optimal controller design procedure for the proposed parallel operation algorithm is introduced, along with informative simulations and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2309-2311
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• 2005

A broadband microstrip balun is proposed and designed using a ${\lambda}/4$short-stub in order to compensate phase imbalance. For the demonstration, two baluns are proposed and designed using a ${\lambda}/4$ shorted stub. One is a modified form of the conventional Wilkinson balun, and the other is a modified ring hybrid. Baluns are implemented on TLX-9 substrate of which the dielectric constant is 2.54 and the thickness is 0.5mm. The measurements show a bandwidth of 500MHz at the center frequency of 2GHz.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.189-195
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• 2003

The steel wheels are widely used in the passenger cars because of their low cost of production although the aluminum wheels have many advantages in their performance and appearance. It is known that the steering wheel vibration with steel wheels is generated more often than one with aluminum wheels. Both the constant velocity driving test and the m up test are carried out in this study to analyze the causes and path of the steering wheel vibration generated from the steel wheels. And this study shows that the steering wheel vibration is affected by the fastening torque of the wheel mounting bolts between the steel wheel and the suspension disk.

• 한국안전학회지
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• 제18권3호
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• pp.126-130
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• 2003

The term stress is currently used to cover a wide variety of phenomena, ranging from physical to social and cultural factors. The term has defined psychological stress as an imbalance between perceived or subjective demand and perceived response capability. The behavior science model has provided the accident proneness through the life change unit factors considering human behavior, life style, ideas, culture, and psychological state. Therefore, this paper presents the Korean life change unit model through statistical testing with the proposed life change unit factors on the unmarried workers living in the middle area. The proposed model can be simply used in real fields in order to minimize the industrial accidents.

• 대한임베디드공학회논문지
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• 제14권4호
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• pp.219-226
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• 2019

One of the most widely studied protocols for tactical ad-hoc networks is Optimized Link State Routing Protocol (OLSR). As for OLSR research, most research work focus on reducing control traffic overhead and choosing relay point. In addition, because OLSR is mostly dependent on link detection and propagation, dynamic Hello timer become research challenges. However, different timer interval causes imbalance of link validity time by affecting link lifetime. To solve this problem, we propose a weighted topology graph model for constructing a robust network topology based on the link validity time. In order to calculate the link validity time, we use control message timer, which is set for each node. The simulation results show that the proposed mechanism is able to achieve high end-to-end reliability and low end-to-end delay in small networks.