• Molecules and Cells
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• 제41권4호
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• pp.301-310
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• 2018

LysR-type transcriptional regulators (LTTRs) contain an N-terminal DNA binding domain (DBD) and a C-terminal regulatory domain (RD). Typically, LTTRs function as homotetramers. VV2_1132 was identified in Vibrio vulnificus as an LTTR that is a homologue of HypT (also known as YjiE or QseD) in Escherichia coli. In this study, we determined the crystal structure of full-length VV2_1132 at a resolution of $2.2{\AA}$, thereby revealing a novel combination of the domains in the tetrameric assembly. Only one DBD dimer in the tetramer can bind to DNA, because the DNA binding motifs of the other DBD dimer are completely buried in the tetrameric assembly. Structural and functional analyses of VV2_1132 suggest that it might not perform the same role as E. coli HypT, indicating that further study is required to elucidate the function of this gene in V. vulnificus. The unique structure of VV2_1132 extends our knowledge of LTTR function and mechanisms of action.

• Journal of Biosystems Engineering
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• 제32권1호
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• pp.30-36
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• 2007

Geothermal heat pump systems use the earth as a heat source in heating mode and a heat sink in cooling mode. These systems can be used for heating or cooling systems in farm facilities such as greenhouses for protected horticulture, cattle sheds, mushroom house, etc. A horizontal type means that a geothermal heat exchanger is laid in the trench buried in 1.2 to 1.8 m depth. Because a horizontal type has advantages of low installation, operation and maintenance costs compared to a vertical type, it is easy to be adopted to agriculture. In this study, to heat and cool farm facilities and obtain basic data for practical application of horizontal geothermal heat pump systems in agriculture, a horizontal geothermal heat pump system of 10 RT scale was installed in greenhouse. Heating performance of this system was estimated. The horizontal geothermal heat pump used in this study had heating COP of 4.57 at soil temperature of 14$^{\circ}C$ for depth of 1.75m and heating COP of 3.75 at soil temperature of 7$^{\circ}C$ for the same depth. The stratification of water temperature in heat tank appeared during the whole heat rejection period.

• 상하수도학회지
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• 제30권1호
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• pp.59-67
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• 2016

Owing to time and cost constraints, new methods that would make it possible to evaluate the safety of the water supply pipeline in a less time- and cost-consuming manner are urgently needed. In response to this exigency, the present study developed a new statistical model to assess the safety of the water supply pipeline using the quantification theory type II. In this research, the safety of the water supply pipeline was defined as 'a possibility of the pipeline failure'. Quantification analysis was conducted on the qualitative data, such as pipe material, coating, and buried condition. The results of analyses demonstrate that the hit ratio of the quantification function amounted to 77.8% of hit ratio, which was a fair value. In addition, all variables that were included in the quantification function were logically valid and demonstrated statistically significant. According to the results derived from the application of the safety evaluation model, the coefficient of determination ($R^2$) between K-region's water supply pipeline safety and the safety inspection amounted to 0.80. Therefore, these findings provide meaningful insight for the measured values in real applications of the model. The results of the present study can also be meaningfully used in further research on safety evaluation of pipelines, establishing of renewal prioritization, as well as asset management planning of the water supply infrastructure.

• 헤리티지:역사와 과학
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• 제53권1호
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• pp.88-105
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• 2020

이 글에서는 신라 황복사지(皇福寺址) 동편 폐고분지(廢古墳址)의 성격에 대한 기존의 제설(諸說)을 검토하고 최근 실시된 발굴조사 결과를 종합하여 고고학적인 접근을 시도해 보았다. 고찰 결과 다음과 같은 연구 성과를 얻을 수 있었다. 첫째, 신라 황복사지 동편 논 경작지 지면에 노출되어 있었던 원형의 거석(巨石)들은 발굴조사 결과 모두 전면(前面)이 호형(弧形)으로 가공된 왕릉(王陵)의 호석(護石)이었다. 이 왕릉의 호석들은 대부분 후대 경작으로 인해 원위치에서 이탈되어 있었고, 일부는 통일신라시대에 조성된 건물의 담장이나 기단 등의 건축부재로 재활용된 상태였다. 이러한 사실은 당시 신라의 계세관념(繼世觀念)과 골품체제(骨品體制) 및 왕실의 권위를 감안할 때 인위적으로 능묘(陵墓)를 파괴한 후의 상황은 아닐 것이다. 따라서 이 왕릉의 석재는 당시 왕의 능원(陵園)이 조영되던 중 어떠한 이유로 인해 미처 완성되지 못하고 방치되어 오다가 후대에 자연스럽게 건물지의 부재로 재활용되었을 것으로 추정된다. 둘째, 구황동(九黃洞)왕릉지 탱석(撑石)의 규모와 암질(岩質)을 비교·분석한 결과 능지탑지(陵只塔址)에 복원되어 있는 십이지신상(十二支神像) 탱석들과 동일한 왕릉의 호석이라는 점이 확인되었다. 이로 인해 황복사지 십이지신상 호석은 또 다른 왕릉의 호석이라는 점이 확인된 것이다. 따라서 그동안 황복사지 십이지신상 호석이 구황동왕릉지에서 옮겨왔을 것이라는 일반적인 학계의 견해는 수정이 불가피하게 되었다. 셋째, 호석의 구조와 능묘 형식으로 본 구황동왕릉지의 피장자(被葬者)는 흥덕왕보다는 늦고, 전(傳)경덕왕릉의 피장자와는 비슷하며, 전(傳)김유신묘의 피장자보다는 앞선 시기의 왕 중에서 찾아진다. 또한 능지탑지로 옮겨진 십이지신상 탱석의 미술사적 형식을 감안해 보더라도 구황동왕릉지의 피장자는 9세기대의 신라 하대 왕 중에서 비정되는 것이 합리적일 것으로 생각된다.

• 헤리티지:역사와 과학
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• 제55권3호
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• pp.152-176
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• 2022

본고는 삼국시대 화살집 복원에 대한 기초 연구로, 기존 화살집 복원 안에 대한 세부내용을 보완하기 위한 연구이다. 현재 발굴된 삼국시대 화살집은 화살을 담는 주머니인 수납부, 그리고 화살집의 등판에 해당하는 배판부로 구성된다. 그러나 2부위는 남아있지 않고, 금속 부품만 발굴되고 있다. 출토된 화살집을 3가지 유형으로 분류하여 복원하였다. 수납부 금구를 중심으로 W자형 부품과 ㄷ자형 부품으로 구성된 1유형, 띠형 금구만 확인된 2유형으로 분류했다. 3유형은 2유형과 비슷하지만 적수금구에서 뻗친 철띠가 띠형 금구에 연결되는 화살집으로, 별도의 유형으로 상정하였다. 3가지 유형의 화살집에 대한 복원 안을 제시하기 전에 적수금구 위치와 유기물 관찰 내용을 반영하였다. 또 출토정황만으로 알 수 없는 적수금구의 위치와 같은 내용은 조선시대 화살집과 일본의 정창원, 하니와에서 관찰되는 화살집 착용방법에서 착안하였다. 적수금구를 기준으로 삼은 기존 화살집 변천 안을 참고하면, 화살집은 본고의 1유형에서 2·3유형으로의 변화한다. 변화의 요인에 대해 화살을 담는 수납부 공간과 화살집을 착용하는 방법의 변화에서 찾았다. 그러나 일부 2·3유형은 1유형의 착장 방식을 유지하고 있고 구식의 부품을 유지된 사례도 있었으며, 함안지역에서는 전형적인 1유형이 늦게까지 부장되는 양상을 확인할 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.446-454
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• 2016

In this paper, we present experimental results of the soil discharge characteristics as a function of moisture content when a 1.2/50-㎲ lightning impulse voltage is applied. For this study, laboratory experiments were carried out based on factors affecting the transient behavior in soils. The electrical breakdown voltages in soils were measured for a 0-6% range of moisture content for sand and a 0 - 4% range of moisture content for gravel. A test cell with semi-spherical electrodes buried face-to-face in the middle of a cylindrical container was used. The distance separating the electrodes is 100 mm. As a result, the time-lag to breakdown in soils decreases as the amplitude of applied voltage increases. The time-lag to initiation of ionization streamer is decreased, with an increase in the moisture content. However, the formative time-lag is rarely changed. The behavior of soil discharges depend not only on the type of soil and its moisture content but also on the amplitude of the impulse voltage. When the test voltage is applied repeatedly, electrical breakdown occurs along different discrete paths, leading radially away from the injected electrode. i.e., the fact that the ionization streamers propagate in different paths from shot to shot was observed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.434-436
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• 2000

It is difficult to accurately measure the ground resistance because it varies widely not only with the type of soil but also with the ground parameters; the moisture, the temperature the buried depth of electrodes, and the ground augmentation material and so on. Therefore, in this paper we analyzed the relation between the parameters and the resistance of ground in order to obtain a method of maintaining ground resistance stable. In experiments, the variation coefficients of ground resistance were calculated by the monthly measured data. The ground resistance decreases as the length of the ground rod increases. The variation between the ground resistance and the moisture rate of soil was low in case of using the ground augmentation material. Without the ground augmentation material, the ground resistance decreases as the moisture rate of soil increases. The ground resistance becomes small when the earth temperature becomes low.

• Geomechanics and Engineering
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• 제6권1호
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• pp.79-98
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• 2014

This paper presents an experimental and numerical study on the evaluation of a thermal response test using a precast high-strength concrete (PHC) energy pile and a closed vertical system with W-type ground heat exchangers (GHEs). Field thermal response tests (TRTs) were conducted on a PHC energy pile and on a general vertical GHE installed in a multiple layered soil ground. The equivalent ground thermal conductivity was determined by using the results from TRTs. A simple analytical solution is suggested in this research to derive an equivalent ground thermal conductivity of the multilayered soils for vertically buried GHEs. The PHC energy pile and general vertical system were numerically modeled using a three dimensional finite element method to compare the results with TRTs'. Borehole thermal resistance values were also obtained from the numerical results, and they were compared with various analytical solutions. Additionally, the effect of ground thermal conductivity on the borehole thermal resistance was analyzed.

• 마이크로전자및패키징학회지
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• 제8권1호
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• pp.61-64
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• 2001

VCO(Voltage Controlled Oscillator)는 통신용 단말기의 크기, 성능 및 전력 소비를 결정하는 중요한 부품중의 하나이다. 통신용 기기의 크기가 점점 작아지고 있는 추세이기 때문에 VCO도 특성의 저하없이 점점 소형화 되고 있다. VCO 모듈을 개발하기에 앞서 회로에 사용되는 수동소자(L,C,R)들에 대한 연구가 진행되었다. 이 과정에서 작은 면적을 차지하면서도 동일한 특성을 나타낼 수 있는 패턴을 고안하였고 이를 적용하였다. 자체 개발된 수동소자 library를 가지고 2차원 simulation을 시행하였고 이를 바탕으로 3차원 회로를 구성하였다. 3차원 회로 구성시 VCO 전체 특성에 크게 영향을 주는 소자들은 trimming이 가능하도록 surface 쪽으로 배치하였다. 공진기 부분에서는 저손실의 stripline 구조를 적용하여 높은 Q값을 얻을 수 있었다. 이러한 과정을 통해 2.3~2.36 GHz에서 동작하는 적층형 VCO를 개발하였다.

• 한국농촌건축학회논문집
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• 제19권3호
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• pp.17-24
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• 2017

The aim of this study is how to understand of structural and elemental landscape image in suburban village. Nowadays, it is well known fact that suburban villages are most likely to be invaded by urbanization. Therefore, the research is focused on how the image of suburb has been changed, what patterns have been created in residential area, what are the different outcomes from different distance, and what are the changes in types of buildings, at particular village called Doojeong in Pyeongtaek city. When collecting supplemental information, elders in village have been participated in comparison of traditional and foreign. The village shows significant characteristics of such phenomenon. According to the research, there are three results. First, ironically, the structural patterns of the village is concentric as seen on urban garden, yet they do not have central function. Second, traditional homes are transformed into functional shape. The most popular roof design that takes 65 percent of whole is modernized flat roof shape. Hanok (Korean traditional house) style is disappearing. Third, due to the massive barn buildings and their monochrome, the beauty of community and architectural harmony are buried.