• Smart Structures and Systems
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• 제26권1호
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• pp.1-10
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• 2020

Turkey is a transcontinental country located partly in Asia and partly in Europe, and hosted by diverse civilizations including Hittite, Urartu, Lydia, Phrygia, Pontius, Byzantine, Seljuk's and Ottomans. At various times, these built many historic monuments representing the most significant characteristics of their civilizations. Today, these monuments contribute enormously to the esthetic beauty of environment and important to many cities of Turkey in attracting tourism. The survival of these monuments depends on the investigation of structural behavior and implementation of needed repairing and/or strengthening applications. Hence, many countries have made deeper investigations and regulations to assess their monuments' structural behavior. This paper presents the dynamic behavior investigation of a monumental masonry mosque, the "İskenderpaşa Mosque" in Trabzon (Turkey), by performing an experimental examination with non-destructive testing. The dynamic behavior investigation was carried out by determining the dynamic characteristic called as natural frequencies, mode shapes and damping ratios. The experimental dynamic characteristics were extracted by Operational Modal Analysis (OMA). In addition, Finite Element (FE) model of masonry mosque was constructed in ANSYS software and the numerical dynamic characteristics such as natural frequencies and mode shapes were also obtained and compared to experimental ones. The paper aims at presenting the non-destructive testing procedure of a masonry mosque as well as the comparison of experimental and numerical dynamic characteristics obtained from the mosque.

• 조명전기설비학회논문지
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• 제21권4호
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• pp.45-52
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• 2007

Electric power is an important element in any modern economy. The availability of a reliable power supply at a reasonable cost is important for the economic growth and development of a country. Electric power utilities throughout the world therefore strive to meet customer demands economically with high quality and reliability. As the power industry moves towards open competition, therefore, there has been a call for a methodology by which to evaluate power system reliability through the use of customer interruption characteristics. This paper presents the results of an investigation and analysis of interruption characteristics of an industrial customer in Korea. This study used a direct visit survey to determine the investigation and analysis of electric service quality and the characteristics of industrial customers in Korea. A customer survey conducted throughout Korea via personal interviews of 660 sample customers is presented here. Variation according to characteristics of interruption such as duration, time of day, frequency and day of interruption was also investigated

• 한국안전학회지
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• 제28권3호
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• pp.63-68
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• 2013

This paper is aimed to make an analysis on characteristics of the parallel arc waveform and RMS of current at the electrical tracking state by conductive powder. In order to achieve the goal in this paper, field state investigation at metal processing companies in Chung-Nam province area was conducted. With the field state investigation, conductive powder were collected from metal processing companies. By experiment on electrical connector(breaker, connector) over which the conductive powder were scattered, arc waveform and RMS of current were measured. The measured waveform and RMS(root-mean-square) of current were analyzed to describe characteristics and patterns of electrical arc by the conductive powder. It was proved that conductive powder on electrical connector can flow electrical current enough to make electrical fire with high thermal energy. Also the change of sine waveform and RMS of current can be used to find out relationship between electrical fire and fault signal by conductive powder. The results obtained in this paper will be very helpful for the prevention of electrical fires occurred at the metal processing companies.

• 보존과학회지
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• 제34권5호
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• pp.407-420
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• 2018

이충무공 종가 관련 고문서는 덕수이씨 후손가에서 보관해오던 것으로 다양한 종류의 문서가 전해지고 있다. 연구대상인 고신교지, 증직교지, 교첩, 교서, 유서, 홍패, 칙명의 국왕문서 7종은 그 제작시기가 명확하고 고문서의 원형을 그대로 유지하고 있어 보존처리 과정에서 과학적 조사 분석을 통해 당시 고문서 제작에 사용되었던 종이 특성을 확인하고 문헌 기록의 내용과 실제 문화재를 일부 비교해 볼 수 있었다. 표면 섬유 형태에서 '외발뜨기(흘림뜨기)' 초지방식으로 제작된 형태 특성이 확인되었으며, 밀도 측정과 종이 표면 분석에서는 대부분의 고문서에서 도침 가공된 종이특성이 관찰되었다. 섬유 분석에서는 모두 닥섬유를 원료로 제작하였으며, 주로 성숙한 닥나무 인피섬유가 사용된 것으로 확인되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.23-28
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• 2002

This paper reports the performance results of hydration heat control of mass concrete walls with pipe cooling system. The thickness of walls ranged from 0.9 to 2.2m. In order to investigate the effect of pipe cooling on the thermal and thermal crack characteristics, the pipe cooling was conducted for 42 walls, and the investigation of thermal cracks was conducted for 14 walls. Based on the investigation, the pipe cooling method decreased the peak temperature of about 13-2$0^{\circ}C$ and the thermal crack width of about 30% for mass concrete walls.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.51-56
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• 2005

For a fire cause judgement this paper describes the short circuit characteristics of a electric wire through the cross section analysis under ac condition. The cower wires prepared for the experiment were 1.2mm, 1.6mm, and 2.0mm in diameter. Through the cross section analysis(CSA), it was confirmed that the dendrite structure grew at the angle of about $40^{\circ}\;or\;60^{\circ}$ when the fusing current was applied to the wires. The larger the fusing current is, the more decreased the growth angle of the dendrite structure is. It was confirmed that the dendrite structure was arranged like the columnar structure. In this paper, the characteristics analysis of short circuit was carried out in the range of transient duration and the correlation constant k was investigated by measuring the short circuit duration and the fusing current.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권2_spc호
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• pp.70-85
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• 2020

This paper introduces the 'Smart Scoping for Environmental Investigations Technical Guide' issued by the US Environmental Protection Agency in 2018, which describes the use of smart scoping during lifecycle of remedial investigation projects. This paper also briefly summarizes the guidelines of soil and groundwater contamination investigation of South Korea. The smart scoping practices can support the development of a robust and realistic conceptual site model that is very useful for investigations and evaluations of the contaminated site. The application of evaluation tools relevant for the site-specific characteristics is important for the development of a conceptual site model. The smart scoping recommends the use of previous investigation data and implementation of best proven strategies for successful remedial investigation project. The use of smart scoping in contaminated site investigation will provide better management of contaminated sites.

• Tribology and Lubricants
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• 제6권1호
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• pp.57-67
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• 1990

For increasing the performance of Machine tools, the improvement of the static and dynamic characteristics of spindle bearing is important. In this paper are the static characteristics, the pressure distribution, friction force and outlet flow rate, and the dynamic characteristics stiffness and damping coefficient, of a cylindrical hydrostatic journal bearing with multi oil pockets are analyzed.

• 한국안전학회지
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• 제27권3호
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• pp.42-48
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• 2012

This paper is aimed to analysis of electrical fire risk by overcurrent and series arc signals in traditional market shops Firstly, the field state investigation was conducted for shops at the traditional market (30 shops). At each shop in the traditional market, load characteristics were investigated and thermal characteristics in Panel were analyzed. Thermal characteristics in Panel is an indicator that can determine the impact of overcurrent. Results of the field state investigation found out four shops which showed abnormal thermal characteristics in Panel. Electrical load characteristics of these 4 shops were simulated by experimental setup consists of generator, motor and heater. In order to verify the electrical fire risk by electrical loads of 4 shops, arc and overcurrent experiments were conducted. The waveshapes of arc and overcurrent are investigated in both the time and frequency domains to find signal characteristics. The results obtained in this paper will be very helpful for the prevention of electrical fires occurred at the shops in the traditional market.

• Membrane and Water Treatment
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• 제13권6호
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• pp.303-312
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• 2022

The natural hydrology and geological conditions of Xintian County was investigated, the development law of regional karst fissures was studied, the groundwater was collected and tested through a large-scale collection of groundwater to obtain the change law of chemical characteristics and water quality characteristics of groundwater, and the water quality evaluation was carried out for the regional karst groundwater in this paper. The results show that, the whole area is dominated by carbonate rock distribution areas, and the distribution of water systems is relatively developed. The strata are distributed from the Lower Paleozoic Cambrian to the Cenozoic Quaternary, and contain multiple first-order folds. The regional karst dynamic action is strong, and many tunnels or caves of different scales were shown, which are conducive to the enrichment of groundwater. Karst groundwater is neutral and alkaline water, the water is clear and transparent with good taste, and meets the national drinking water hygiene standards. The content of toxic trace elements and fluoride in the water source is generally lower than the limit value specified by the national standard and the accumulated toxic heavy metals is never found. The overall water quality is of good quality and suitable for the development and utilization of various purposes.