• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1483-1485
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• 2005

In recent years, customers and power supplies are interested in power quality. Demands of customers are change from standard quality of distribution power system to various high quality of distribution power system. so, it is necessary to apply power quality compensator. in our project, we develop the UPQC(Unfied Power Quality Compensator of 45kVA which compensates power factor and voltage sag, interruption. it is very frequently occurred power quality problems. As a series and shunt compensator, UPQC consists of two inverters with common dc link capacitor bank. It compensates the current quality in the shunt part and the voltage quality in the series part. In this paper, we present simulation and test result of developed UPQC system. Test for UPQC are performed at voltage sag, flickers and non-linear load conditions. For voltage sag and ficker generation, we use RTDS(Real Time Digital Simulator) and power amplifier system.

• 대한원격탐사학회지
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• 제26권6호
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• pp.721-730
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• 2010

In satellite remote sensing, irregular temporal sampling is a common feature of geophysical and biological process on the earth's surface. Lee (2008) proposed a feed-back system using a harmonic model of single period to adaptively reconstruct observation image series contaminated by noises resulted from mechanical problems or environmental conditions. However, the simple sinusoidal model of single period may not be appropriate for temporal physical processes of land surface. A complex model of multiple periods would be more proper to represent inter-annual and inner-annual variations of surface parameters. This study extended to use a multi-periodic harmonic model, which is expressed as the sum of a series of sine waves, for the adaptive system. For the system assessment, simulation data were generated from a model of negative errors, based on the fact that the observation is mainly suppressed by bad weather. The experimental results of this simulation study show the potentiality of the proposed system for real-time monitoring on the image series observed by imperfect sensing technology from the environment which are frequently influenced by bad weather.

• 한국실내디자인학회논문집
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• 제24권4호
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• pp.80-90
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• 2015

This study aims to improve plans by analyzing spatial compositions of cohousing common houses, their role depending on the types of users and spaces, and satisfaction from the user-oriented design perspective. For this study, a basic concept was examined based on previous studies and literature reviews. So-Haeng-Ju(Happy House with Communication) Houses 1, 2, and 3 in Seongmisan Village was analyzed. As well, interviews with residents of these houses were conducted to analyze the role of user behavior in common house depending on the types of users and spaces. As a result, it was found that there were common characteristics of roles in an exchange with neighbors, cooperative child-care, and residents' meetings. The time and behavioral types were different depending on the living patterns, characteristics, and family members of residents. User satisfaction with the locations of community facilities including communal kitchen and communal living room, the composition of rooms, communication with residents, and the connection between communal living space and personal living space, was above the average. However, user satisfaction with storage facilities, or defect repair and facility maintenance was low. Most of cohousing common house users were satisfied with the use and size of spaces, and a sense of community, including communication with neighbors beyond the environment and Seongmisan Village. In conclusion, a realistic alternative is required for future cohousing by developing a system regarding human resources networks and cost bearing issues.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1251-1254
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• 2016

Background: Oral squamous cell carcinoma (OSCC), the most common malignancy of the oral cavity, shows geographical variation with respect to the age, sex, site and habits of the population. The histolopathologic grade of the tumor is closely related to its tissue of origin. This study was conducted to establish the prevalence of OSCC in relation to patient sex, age, habits and sites of lesions. Materials and Methods: A total of 130 cases of histopathologically diagnosed OSCC were selected for the study, out of which 66, 38 and 26 were well (WD), moderately (MD)and poorly differentiated (PD), respectively. Sections were stained with haematoxylin and eosin and graded according to a modified Borders's system. Then statistically analyzed different grades of OSCC for correlations with other variables. Results: In our study the majority cases of OSCC were found in the 5th to 7th decades of life, males acconting for 53%. The most common site was the buccal mucosa and most cases had habit of tobacco use either in the form of chewing or smoking or both. When the different grades of OSCC were compared with different sites a statistically significant value was observed (P=0.029). Conclusions: The incidence of high grade PD is very much less in female patients but in males such lesions were common. In our location population the buccal mucosa is the most common site due to the tobbaco habits of the patients and majority cases of the buccal mucosa are WD whereas in tongue, floor of the mouth and palate PD are common.

• 농촌계획
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• 제28권1호
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• pp.1-15
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• 2022

A Care farm is known to have positive effects on various people in psychological, physical, and social aspects. However, care farm services for the disabled, transportation disadvantaged, and socially disadvantaged are limited. This study conducted a demand survey in order to provide basic data for development of the Agro-Healing Virtual Reality Therapy(AVRT) system. The respondents were the ordinary person(n=127) and the disabled person(n=72), and the survey items consisted of 4 categories and 20 items, including intention to use AVRT, requirements for use, factors to be considered when developing the system, and content and program preferences. The intention to use a AVRT was found to be at a high level of 80% or more by respondent characteristics. In addition, similar results were shown in all items such as virtual reality experience, willingness to use, appropriate use time, and willingness to pay by respondent characteristics, and correlation by item was determined through correlation analysis. As for the conditions of use, both sides preferred rural types and were found to have the purpose of healing. However, there were concerns about dizziness in common between system use, and in the case of the disabled person, there were difficulties in purchasing expensive equipment. In the development of the AVRT system, the part of sensory priority, important technology level, and color preference were evaluated, and the preference of content and programs to be developed in the system was identified. Fruit, vegetables, flowers, and animals preferred mandarin, tomato, tulips, and dogs first, horticultural healing preferred harvest management for the ordinary person, plant cultivation for the disabled person, and forest healing and animal education preferred walking and dog-related programs. However, agricultural work was found to be a program with high preference for making processed foods for the ordinary person and creating an animal breeding environment for the disabled person. The result of this study is expected to provide reference data that can be suggested for the development of Agro-healing Virtual Reality Therapy system.

• International Journal of Railway
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• 제2권2호
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• pp.50-59
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• 2009

Numerous train operating companies provide training by means of driving simulators. A detailed analysis in the course of the rail research project 2TRAIN has shown that the simulation technology, the purposes of training and the overall concept of simulator-based training are rather diverse (Schmitz & Maag, 2008). A joint factor however are weak assessment capabilities and the fact that the simulator training is often not embedded into the overall competence management. This fact hinders an optimal use of the simulators. Therefore, 2TRAIN aims at the development of enhanced training and assessment tools. Taking into account that several simulators are already in use, the focus lays on the extension of existing simulation technology instead of developing entirely new systems. This extension comprises (1) a common data simulation interface (CDSI), (2) a rule-based expert system (ExSys), (3) a virtual instructor (VI), and (4) an _assessment database (AssDB). The foundation of this technical development is an assessment concept (PERMA concept) that is based on performance markers. The first part of the paper presents this assessment concept and a process model for the two major steps of driver performance assessment, i.e. (1) the specification of exercise and assessment and (2) the assessment algorithm and execution of the assessment. The second part describes the rationale and the functionalities of the simulator add-on tools. Finally, recommendations for further technical improvement and appropriate usage are given. based on the results of a pilot study.

• 대한임베디드공학회논문지
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• 제9권6호
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• pp.323-334
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• 2014

In this paper, we proposed indoor positioning system with improved accuracy. The proposed indoor location measurement system is based pedestrian location measurement method that use the embedded sensor of smartphone. So, we do not need wireless external resources, such as GPS or WiFi signals. The conventional methods measure indoor location by generating a movement route of pedestrian by step and direction recognition. In this paper, to correct the direction sensor error, we use the common feature of the normal indoor floor map that the indoor path is lattice-structured. And we quantize moving directions depending on the direction of indoor path. In addition, we propose moving direction measuring method using geomagnetic sensor and gyro sensor to improve the accuracy. Also, the proposed step detection method uses angle and accelerometer sensors. The proposed step detection method is not affected by the posture of the smartphone. Direction errors caused by direction sensor error is corrected due to proposed moving direction measuring method. The proposed location error correction method corrects location error caused by step detection error without the need for external wireless signal resources.

• 한국레이저가공학회지
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• 제13권4호
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• pp.7-13
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• 2010

Today, the most common process for generating Through Silicon Vias (TSVs) for 3D ICs is Deep Reactive Ion Etching (DRIE), which allows for high aspect ratio blind holes with low surface roughness. However, the DRIE process requires a vacuum environment and the use of expensive masks. The advantage of using lasers for TSV drilling is the higher flexibility they allow during manufacturing, because neither vacuum nor lithography or masks arc required and because lasers can be applied even to metal and to dielectric layers other than silicon. However, conventional nanosecond lasers have the disadvantage of causing heat affection around the target area. By contrast, the use of a picosecond laser enables the precise generation of TSVs with less heat affected zone. In this study, we conducted a comparison of thermalization effects around laser-drilled holes when using a picosecond laser set for a high pulse energy range and a low pulse energy range. Notably, the low pulse energy picosecond laser process reduced the experimentally recast layer, surface debris and melts around the hole better than the high pulse energy process.

• 한국인터넷방송통신학회논문지
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• 제17권3호
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• pp.175-181
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• 2017

스마트 폰의 대중화에 따라 전방주시태만으로 인한 교통사고가 급증하고 있다. 요즘 대부분의 운전자들이 사용하는 내비게이션 시스템은 도로 정보를 확인하는 과정에서 운전자의 시선을 분산 시킨다. 이에 우리는 전투기 조종사를 위해 개발된 기술인 HUD(Head-Up-Display)를 차량용 내비게이션에 적용하는 연구를 수행 하였으며 이 논문에서는 HUD를 적용한 자동차 내비게이션의 개념과 구조 및 개발방법을 기술하였다. 이러한 내비게이션은 운전가의 시선을 차량 전면으로 유지시켜주어 시선분산을 최소화하고 시야확보를 도와준다. 따라서 우리가 제안하는 HUD 내비게이션이 대중화 되면 전방주시태만으로 인한 교통사고가 획기적으로 줄어들 것이다.

• 설비공학논문집
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• 제30권3호
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• pp.107-115
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• 2018

A design combining the use of a compressor and expander was introduced in order to improve the cycle performance of a $CO_2$ automotive air conditioning system. Both the compressor and expander used were of rotary vane type and were designed to share a common shaft in a housing. Numerical simulation was carried out to evaluate the merit of the combined unit. In a typical automotive air conditioning operating conditions, the COP of the system was improved by 8.7% by the application of the combined unit. The compressor input was reduced by 5.2% through use of the expander output. In addition, about 3.06% increase in the cooling capacity was obtained through isentropic expansion in the expander. Our study noted that, as the pressure difference between the gas cooler and the evaporator becomes larger, the COP of the system improved increases unless the mass flow rate in the expander exceeds that in the compressor.