• 한국주거학회논문집
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• 제8권3호
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• pp.231-236
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• 1997

After 1970 Years. Korea has developed a concept of public domestic housing. But this house is reached the uppermost limit time of using the occupant's satisfying life. Then reconstruction of Apartment house is urgently needed which is developed in Korea. So this study is examined the demolition work on current reconstructing apartment site. for reconstruction. Therefore this research examined the fitted demolition time of low-rise house and characteristics of demolition works. The conclusions from this experiment are shown below. 1. The average day work in clutcher method is shown about 1, 032㎥/Day. 2. The calculations of the term of construction which is produced by the analysis of demolition construction period on low-rise house is below. D(day) ＝ S(day) ＋ (0.272＋0.000902b(㎥))＋R(day)

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1773-1775
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• 1998

This paper deals with the pulse generator using PFN(Pulse Forming Network), and its operation characteristics and application. Two kinds of pulse generator were composed of the best appropriate condition circuit. The output current of the one pulse generator has the rise time of 28 ns and the pulse duration of $7{\mu}s$. The other pulse generator has high current of about 2kA. By use of the former generator with rapid rise time, the impulse impedance characteristic of ground electrodes was investigated with measuring the ground potential rise when the pulse current was injected into the ground electrode.

• 국제초고층학회논문집
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• 제3권4호
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• pp.255-271
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• 2014

A method of smart system identification of super high-rise buildings is proposed in which super high-rise buildings are modeled by a shear-bending system. The method is aimed at finding the story shear and bending stiffnesses of a specific story only from the horizontal floor accelerations. The proposed method uses a set of closed-form expressions for the story shear and bending stiffnesses in terms of the limited floor accelerations and utilizes a reduced shear-bending system with the same number of elements as the observation points. A difficulty of prediction of an unstable specific function in a low frequency range can be overcome by introducing an ARX model and discussing its relation with the Taylor series expansion coefficients of a transfer function. It is demonstrated that the shear-bending system can simulate the vibration records with a reasonable accuracy. It is also shown that the vibration records at two super high-rise buildings during the 2011 Tohoku (Japan) earthquake can be simulated with the proposed method including a technique of inserting degrees of freedom between the vibration recording points. Finally it is discussed further that the time-varying identification of fundamental natural period and stiffnesses can be conducted by setting an appropriate duration of evaluation in the batch least-squares method.

• 한국응용과학기술학회지
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• 제35권4호
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• pp.1393-1406
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• 2018

본 연구는 3개의 운전변수(압력, 공기량, 운전시간)를 실험 설계하고 마이크로 버블의 종말부상속도(Terminal rise velocity)를 반응 값으로 하여 예측식 모델과 최적 조건을 수립하였다. 다항식 회귀분석을 통해 펌프의 압력($X_1$) 4.5bar, 공기량($X_2$) 3.3L/min 그리고 운전시간($X_3$)이 2.2min에서 종말상승속도(Terminal rise velocity)에 대한 최적값인 5.14 cm/min ($85.7{\mu}m/sec$)을 얻었다. 또한, 레이저 입자계수 측정장치를 이용하여 $2{\sim}5{\mu}m$ 및 $25{\sim}50{\mu}m$ 영역에서의 가장 높은 마이크로버블 직경크기 분포를 확인하였다.

• 수면정신생리
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• 제13권1호
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• pp.15-21
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• 2006

배 경：이 연구에서는 한국 대학생들의 취침시각, 기상시각, 취침시간을 평일과 휴일로 나누어 조사하였다. 또한, 성별, 연령, 학년이 한국 대학생들의 취침시각, 기상시각, 취침시간, 평일-휴일 간 수면 차이 등에 미치는 영향을 살펴보았다. 방법：한국내 4년제 대학 12개의 대학생들을 대상으로 평일과 휴일의 수면양상을 설문 조사하였다. 총 1,825명(여자 1,416명, 남자 409명, $18{\sim}30$세, 평균 연령 $21.1{\pm}2.2$세)의 결과를 분석하였다. 결과：한국 대학생들은 평일보다 휴일에 50분 늦게 취침하고(평일 00시 49분；휴일 01시 40분；t=39.67, p<0.001), 1시간 58분 늦게 일어나며(평일 07시 52분；휴일 09시 50분；t=39.46, p<0.001), 1시간 8분 더 오래 취침하였다(t=13.33, p<0.001). 남학생들에 비해 여학생들이 평일과 휴일 모두에서 일찍 자고(t=7.10, p<0.01；t=6.04, p<0.01), 일찍 일어나며(t=8.96, p<0.01；t=3.89, p<0.01), 평일 취침시간이 적었다(t=1.99, p<0.01). 또한, 여학생들에서 남학생들에 비해 휴일의 기상시각이 더 연장되고(t=3.41, p<0.01) 취침시간이 더 증가하였다(t=3.68, p<0.01). 학년이 증가할수록 평일 취침시각, 평일 기상시각, 휴일 취침시각이 느려졌고(${\beta}=0.1009$, p<0.01；${\beta}=0.1022$, p<0.01；${\beta}=0.1096$, p<0.01), 휴일 취침시간이 줄어들었으며(${\beta}=-0.0990$, p<0.01), 휴일과 평일의 기상시각 차이나 취침시간 차이가 줄어들었다(${\beta}=-0.0906$, p<0.01；${\beta}=-0.1115$, p=0.02). 결론：한국 대학생들은 평일에 비하여 휴일에 취침시각과 기상시각이 늦고 취침시간이 길었다. 이 결과는 한국 대학생들의 평소 일정이 생물학적인 수면각성 주기에 비해 앞으로 당겨져 있어 평일에 수면이 부족함을 의미한다. 또한, 평일과 휴일의 기상시각과 취침시간의 차이는 여학생과 저학년에서 더욱 두드러져, 수면각성주기 이탈과 수면부족이 여학생과 저학년에서 더욱 심하다는 것을 시사하였다.

• Earthquakes and Structures
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• 제19권3호
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• pp.175-188
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• 2020

The Hengda Group super high-rise building in Jinan City uses the frame-core tube structural system. With a height of 238.3 m, it is above the B-level height limit of 150 m for buildings within 7-magnitude seismic fortification zones. Therefore, it is necessary to apply performance-based seismic design to this super high-rise building. In this study, response spectrum analysis and comparative analysis of the structure are conducted using two software applications. Moreover, elastic time-history analysis, seismic analysis under an intermediate earthquake, and elastic-plastic time-history analysis under rare earthquakes are performed. Based on the analysis results, corresponding strengthening measures are implemented at weaker structural locations, such as corners, wall ends connected to framed girders, and coupling beams connected to framed girders. The failure mode and failure zone of major stress components of the structure under rare earthquakes are analysed. The conclusions to this research demonstrate that weaker locations and important parts of the structure satisfy the requirements for elastic-plastic deformation in the event of rare earthquakes.

• The Korean Journal of Physiology and Pharmacology
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• 제6권2호
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• pp.81-85
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• 2002

Conventional views of synaptic transmission generally overlook the possibility of 'postfusional-control' the regulation of the speed or completeness of transmitter release upon vesicular fusion. However, such regulation often occurs in non-neuronal cells where the dynamics of fusion-pore opening is critical for the speed of transmitter release. In case of synapses, the slower the transmitter release, the smaller the size and rate-of-rise of postsynaptic responses would be expected if postsynaptic neurotransmitter receptors were not saturated. This prediction was tested at hippocampal synapses where postsynaptic AMPA-type glutamate receptors (AMPAR) were not generally saturated. Here, we found that the small miniature excitatory postsynaptic currents (mEPSCs) showed significantly slower rise times than the large mEPSCs when the sucrose-induced mEPSCs recorded in cyclothiazide (CTZ), a blocker for AMPAR desensitization, were sorted by size. The slow rise time of the small mEPSCs might result from slow release through a non-expanding fusion pore, consistent with postfusional control of neurotransmitter release at central synapses.

• Earthquakes and Structures
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• 제15권4호
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• pp.443-452
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• 2018

In this paper the new intensity measures (IMs) for probabilistic seismic analysis of RC high-rise buildings with core wall structural system are proposed. The existing IMs are analysed and the new optimal ones are presented. The newly proposed IMs are based on the existing ones which: 1) comprise a wider range of frequency velocity spectrum content and 2) are defined as the integral along the velocity spectrum. In analysis characteristics of optimal IMs such as: efficiency, practicality, proficiency and sufficiency are considered. As prototype buildings, RC high-rise buildings with core wall structural system and with characteristic heights: 20-storey, 30-storey and 40-storey, are selected. The non-linear 3D models of the prototype buildings are constructed. 720 non-linear time-history analyses are conducted for 60 ground motion records with a wide range of magnitudes, distances to source and various soil types. Statistical processing of results and detailed regression analysis are performed and appropriate demand models which relate IMs to demand measures (DMs), are obtained. The conducted analysis has shown that the newly proposed IMs can efficiently predict the DMs with minimum dispersion and satisfactory practicality as compared to the other commonly used IMs (e.g., PGA and $S_a(T_1)$). The newly proposed IMs overcome difficulties in calculating of integral along the velocity spectrum and present adequate replacement for IMs which comprise a wider range of frequency velocity spectrum content.

• 환경영향평가
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• 제19권6호
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• pp.583-590
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• 2010

To determine nocturnal inversion characteristics at the leeward side of high-rise building, air temperature data were observed at 10 minute interval from February 22, 2010 to April 15, 2010. The observed data were compared, analyzed and examined to illustrate air temperature differences between the roof (XAR) and surface (XAG) of X apartment. The wind speed, wind direction and precipitation data were also observed at XAR and YJL (Yangjae Stream) sites at the same time. After the analysis, the maximum nocturnal inversion was observed by $4.0^{\circ}C$ at 3:40, 3:50, 4:10 on February 24th 2010, at that time the weather condition was clear and weak wind. Air temperature inversions at the leeward side of high-rise building were observed on whole day in wintertime and air temperature inversion intensity was also higher than other nearby area (SMG).

• 국제초고층학회논문집
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• 제9권4호
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• pp.351-360
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• 2020

Monitoring civil structures periodically is necessary for ensuring the fitness of the structures. Cracks on inner and outer surfaces of the building plays a vital role in indicating the health of the building. Conventionally, human visual inspection techniques were carried up to human reachable altitudes. Monitoring of high rise infrastructures cannot be done using this primitive method. Also, there is a necessity for more accurate prediction of cracks on building surfaces for ensuring the health and safety of the building. The proposed research focused on developing an efficient crack classification model using Transfer Learning enabled EfficientNet (TL-EN) architecture. Though many other pre-trained models were available for crack classification, they rely on more number of training parameters for better accuracy. The TL-EN model attained an accuracy of 0.99 with less number of parameters on large dataset. A bench marked METU dataset with 40000 images were used to test and validate the proposed model. The surfaces of high rise buildings were investigated using vision enabled Unmanned Arial Vehicles (UAV). These UAV is fabricated with TL-EN model schema for capturing and analyzing the real time streaming video of building surfaces.