• 한국정밀공학회지
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• 제34권1호
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• pp.19-22
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• 2017

This paper describes the efficient equipment maintenance that can offer the exact time for repair and change of component in root industry. A conventional method offered the fixed time for repair and change of component because the method is based on early guarantee specification of the component. However the operating condition of manufacturing field is often under worse condition than early guarantee condition for high productivity. So, most components can't use until early guarantee time due to the operation of various different condition. Therefore we suggest the useful method for efficient equipment-maintenance by manufacturing-field analysis and feedback database. For this, the classification of root industry and related equipment is performed and then the detail classification of the process and component for equipment maintenance. And the monitoring module is also designed to gather data for feedback process and the environment is basically implemented for aging and reliability test.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.149-155
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• 2003

Objectives of this research were to fractionate heavy metals in soil samples in the upper Okdong River basin and to assess the potential pollution index of each metal fraction. Soil samples were collected from cultivated land soils and analyzed for physical and chemical properties. pH of cultivated soils ranged from 5.2 to 7.6. Contents of total kelhaldal nitrogen and loss on ignition were in the ranges of 0.6∼2.5%, and 1.9∼12.9%, respectively. Heavy metals in the cultivated land soils were higher in the abandoned closed coal mine near field soils than those in the paddy soils. Total concentrations of metals in the cultivated land soils were in the orders of Zn > Pb > Ni > Cu > Cd, exceed the corrective action level of the Soil Environment Conservation Law and higher than the naturals were abundance levels reported from uncontaminated cultivated land soils. Mobile fractions of metals were relatively small compared to the total concentrations. Soil Pollution Assesment Index(SPAI) values of each fraction of metals were leveled from Non polluted to Moderately polluted based on total concentrations. SPAI values of mobil fractions were lower than those of immobile fractions. Results on metal fractions and SPAI values of the cultivated land soils indicate that field soils samples were contaminated with heavy metals and had potential to cause a detrimental effects on plants. A prompt countermeasure to prevent field soils in the abandoned closed coal mine near fields are urgently needed.

• 국제초고층학회논문집
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• 제2권4호
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• pp.293-314
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• 2013

Double-Skin Façade (DSF), which is a kind of passive indoor environmental control technique, is effective way to control environmental loads while maintaining the transparency especially in perimeter zone and hence the adoption example of DSF keep increasing recently. The objective of this study was to perform a field survey of air quality environment with natural ventilation through DSF and thermal environment within office building with six stories during a mild climate period in Japan. Moreover, to understand the comprehensive environmental performance of the target building, questionnaire survey was conducted to subjectively evaluate the productivity and satisfaction with the environmental factors in office space. In this field measurement, there was a positive correlation between the DSF internal ventilation flow and the amount of solar radiation on the DSF normal surface; the primary driving force for ventilation in the DSF was considered to be the buoyancy force caused by solar radiation. The results of questionnaire survey with regard to productivity level indicated the need for improvement in the thermal (temperature) and spatial environment (room size and furniture placement).

• 융합보안논문지
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• 제18권1호
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• pp.3-11
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• 2018

오늘날 새롭게 등장한 Science of Security (SoS)라는 분야는 사이버 보안 영역에 대한 과학적인 접근 방법을 적용한 연구분야로서 보안 영역에서 등장한 새로운 패러다임이라고 할 수 있다. 복잡하고, 큰 규모 네트워크 환경의 동적인 변화와 다수의 프로토콜과 메커니즘 환경이 존재하는 현대에 이러한 네트워크 환경에 대한 보안을 위해 Formal Model과 자동화 분야를 연구하는 방향이다. 따라서 본 연구에서는 SoS와 같은 최신 사이버 보안 연구 동향에 대해서 분석하고, 선진국들의 연구 동향사례들을 조사하여 국내의 사이버 보안 개발 방향에 대해 새로운 접근 방법을 검토하고자 한다. 또한 다양한 사이버 보안의 패러다임에 대한 과학적 보안 연구 방법에 대해 국내의 현황을 분석해 보고 국내 사이버 보안 활성화에 대한 방향을 제시하고자 한다.

• 대기
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• 제33권2호
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• pp.173-195
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• 2023

Research papers in the field of atmospheric environment published in three Journals: Journal of Korean Meteorological Society, Atmosphere, and Asia-Pacific Journal of the Atmospheric Sciences, are all summarized over period of 60 years since the establishment of Korea Meteorological Society (KMS) in 1963. In addition, current research trends and future outlook in the atmospheric environment field has been also highlighted. The results of historical records published in three KMS journals indicated that the activities, contents, and scope of researches carried out by KMS members in the field of atmospheric environment have yielded the enormous and rapid progress in each of the all four areas over 60 years. In particular, as the chronological progress of observational instruments and availability of satellite data such as from GEMS can be a great asset to deepen the observational and modeling researches in the current and future studies, it is highly anticipated that the more progressive and in-depth studies can be achievable to abate the air pollutants over the Korea as well as northeast Asia.

• Transactions on Electrical and Electronic Materials
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• 제9권6호
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• pp.265-272
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• 2008

In this paper, AC losses of long wire Bi-2223 tapes with different twist pitch of superconducting core were fabricated, measured and analyzed. These samples produced by a powder-in-tube method are multi-filamentary tape with Ag matrix. Also, it's produced by non-twist. The critical current measurement was carried out under the environment in Liquid nitrogen and in zero field by 4-prob method. And the Magnetic measurement was carried out under the environment of applied time-varying transport current by transport method. From experiment, the susceptibility measurements were conducted while cooling in a magnetic field. Flux loss measurements were conducted as a function of ramping rate, frequency and field direction. The AC flux loss increases as the twist-pitch of the tapes decreased, in agreement with the Norris Equation. Neutron-diffraction measurements have been carried out investigate the crystal structure, magnetic structures, and magnetic phase transitions in Bi-2223([Bi, Pb]:Sr:Ca:Cu:O).

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.500-503
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• 2003

The navigation problem of robot is one of the main themes to deal with conficts or interferences between obstacles and the robot itself In this case, while the robot avoids obstacles on the space, the passage route should be determined efficiently. In order to solve problems above, we have come up with the distance field space medel (DFM) and then, under known environment, we have presented the distance field A algorithm for passage route path search. In this research, the method of performing the 3-dimensional passage route path search of robot under unknown environment is proposed. It is shown that the authors can build the distance search model the does not need space division by taking into account of sensor information to a distance field space model, and constructing this information as virtual obstacle information.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.3040-3042
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• 2005

During the last several years, interest in broad-band power line communications (PLC) has been grown over medium voltage(MV) power distribution lines as well as low voltage lines. This paper introduces a medium voltage PLC test field that is set up in the suburbs of Euiwang city in Korea. This test field could be used not only for the measurement of communication channel environment but also for internet service. This paper shows the configuration of medium voltage test field with network devices like MV signal coupler and the results of channel environment like noise and impulse response. It also shows the service performance of PLC access network through network management system.

• 한국대기환경학회지
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• 제17권2호
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• pp.223-231
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• 2001

In order to provide some insights into the influence of electric field, gas composition, and gas temperature on electron energy distribution and electron transport characteristics, the Boltzmann equation was solved by using cross section data for electron collisions, Critical electric fields for the corona development in dry air and flue gas are 150 and 80 Td, respectively. It was seen that the decrease of critical electric field in flue gas is mainly caused by the $H_2O$ addition through the comparison of ionization and attachment coefficients of gas components. Increase of $O_2$, $H_2O$, and $CO_2$ contents in gas affected discharge characteristics according to their reciprocal characteristics between lowering the ionization threshold and increasing the electro-negativity. As electric field increases, electrons with higher energies in the electron energy distribution also increase. The mean and characteristic electron energies also linearly increase with electric field. The variation of flue gas temperature did rarely affect on the electron energy distribution function and electron transport characteristics, because the gas temperature is several hundreds or thousands times lower than the electron temperature.

• 한국대기환경학회지
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• 제15권1호
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• pp.33-39
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• 1999

This study has been performed to develop an efficient electrocharged scrubber. To improve collection efficiency of the scrubber, electric-charger was installed at the forefront of the packed crossflow scrubbers, and an experiment of changing discharge electrode shape and fluctuating electric field strength was undertaken. After using a light-oil boiler for generation of particles in the about 80% weight of submicron size particles was exhausted. Collection characteristics of the electrocharged scrubber were similar to those of two-stage electrostatic precipitator. In this study the collection efficiency of submicron size particles has been much improved, compared with the previous ones. In an experiment of changing discharge electrode and electric field strength, a needle-spike shape wire electrode showed a higher collection efficiency than round shape wire. The collection efficiency becomes increased with an increase of electric field strength.