• The Korean Journal of Financial Management
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• v.27 no.2
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• pp.145-167
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• 2010

We investigate the dynamic relationship between stock returns and investors' behavior. For the putpose of the paper, daily KOSPI returns are decomposed into two parts: overnight returns and daytime returns. Overnight return is measured by the closing price of the previous day and the opening price of the current day. And daytime return is measured by the opening and closing prices of the current day. Qvernight returns are assumed to reflect global economic information, and daytime returns, domestic or local information. Major results are as follows: Foreign investors' behavior has an effect on the overnight returns more than the daytime returns. Individual investors' behavior, however, has little effect on the overnight returns, but not the daytime returns. Consequently, forecast error variance decomposition shows that the variance explanation power of foreign investors is higher in overnight returns rather than in the daytime returns. And the variance explanation power of individual investors is higher in daytime returns rather than in overnight returns. It implies that foreign investors employ dynamic hedging strategies and give more weight to global economic information rather than to domestic information. We conclude that investment behavior of foreign investors and domestic individuals is based on different economic information. This paper's findings are consistent with the economic situation that the Korean capital markets have faced since the global financial crisis of August 2008.

• Journal of agriculture & life science
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• v.43 no.5
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• pp.47-55
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• 2009

This study analyzes the correlation between noise and the size of urban forests. Under the assumption that the main cause of the noise m the city is the population density, the size of urban forests per capita and the ratio of urban forests with respect to the size of urban per 100 thousand persons are used for the calculation of correlations with noise. The results of the calculations of Pearson's and Spearman's correlation coefficients indicate that the increase in the size of urban forests has a significant effects in reducing the day-time as well as night-time noise for most regions in the cities. The size of urban forests within public parks has a significantly negative correlation with the noise. However, calculated correlation coefficients imply the increase in the size of total urban forests is more effective in reducing the noise than the increase in the urban forests in public parks.

• The Korean Journal of Applied Statistics
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• v.23 no.5
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• pp.823-834
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• 2010

Stock markets perpetually accumulate information. During trading hours the price instantaneously reacts to new information, but accumulated overnight information reacts simultaneously on the opening price. This can create opening price uctuations. This study explores the overnight information e ects on intra-da stock market volatility. GARCH models and the VKOSPI model are provided. Empirical data includes daily opening and closing prices of the KOSPI 200 index and the VKOSPI from March $3^{rd}$ 2008 to June $22^{th}$ 2010. Empirical results show that the VKOSPI signi cantly decrease during trading time when positiv overnight information moves the Korean stock upward. This study provides useful information to investors since the Korea Exchange plans to introduce a futures market for the VKOSPI soon.

• Environmental and Resource Economics Review
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• v.4 no.2
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• pp.223-242
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• 1995

본 연구는 1977년 부터 한국에서 적용된 계절 시간대별 차등요금에 대한 반응성을 분석하기 위하여 각 요금적용시간대에 대한 전력소비의 탄력성을 1987년 1월부터 1992년 12월 까지의 자료를 이용하여 초월대수 비용 함수 (Translog Cost Function)을 이용하여 추정 분석하였다. 추정결과 낮 시간대, 저녁시간대, 밤 시간대에 대한 자기가격탄력성은 산업용(을) 고압 A 수용가의 경우 각각 -0.386, 0.351, -0.114이며, 고압 B 수용가는 각각 -0.095, -0.230, -0.192이었다. 일반적으로 대규모 수용가(고압 B)는 소규모 수용가(고압 A)에 비해 계시별 요금제에 대한 반응성이 더 낮은 것으로 나타났다. 한편 교차가격 탄력성 산출결과 상호 시간대간에 전력사용량의 대체성이 존재함을 알 수 있다. 즉, 산업용(을) 고압 A 수용가는 낮시간대와 저녁시간대간에 강한 대체성이 나타났으며, 산업용(을) 고압 B 수용가는 저녁시간대와 밤시간대간에 대체성이 높은 것으로 나타났다. 또한 계시별 요금제 구조의 변화에 따른 수용가의 반응성을 분석하기 위해 표본기간을 1987년 1월 부터 1989년 12월 까지(기간 I)와 1990년 1월 부터 1992년 12월 까지 (기간 II)로 분리하여 탄력성을 추정하였다. 기간 I에서는 계시별 요금제에 대한 수용가의 반응성이 아주 낮았으나, 기간 II에서는 현저하게 높아졌다. 이러한 결과로 보아 기간 II에서 시행된 1991. 6의 요금구조 개편은 수용가의 반응성을 증가시키는데 크게 기여하였으며, 이에 따라 계절 시간대별 차등 요금제가 부하관리를 위한 효율적인 방법임을 알 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.766-769
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• 2016

산업시설 가운데 화력발전소에 스마트 부하관제 시스템을 이용하여 메탈 조명을 LED 조명으로 대체하여 전력을 절감하였다. LED 조명의 빛의 세기를 조절 할 수 있는 디밍을 통해서 사용자의 다양한 요구사항을 반영할 수 있다. 수요 예측은 전력 사용량이 많은 시간대의 전력사용량을 분산시키는 시스템이다. 수요 예측 스케줄에 의해서 목표전력량에 도달하기 위해 설정된 시간대에 디밍으로 LED 조명의 전력량을 조절하여, 기존 LED 조명 대비 전력량을 27.8% 절감하였다. 외부에 눈과 비가 오거나 밤에 실내가 어두워져서 작업 환경에 영향을 미치는 경우가 있다. 실시간으로 조도를 측정하여 작업 환경이 원활한 기준조도에 맞도록 LED 조명을 디밍 하여 작업환경을 개선하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.176-179
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• 2020

현재 대부분의 객체 탐지 알고리즘은 RGB 영상을 기반으로 개발되고 있다. 하지만 안개가 끼거나 비가 오는 날 또는 방중에 촬영한 RGB 영상은 흐리거나 잘 보이지 않아 높지 않은 객체 탐지 결과를 보여줄 수 있다. 열 적외선 영상은 열 센서로 인해 만들어지든 영상으로 RGB 영상에 비해 기상조건이나 촬영 시간대에 상관없이 취득 될 수 있다. 본 논문에서는 RGB 영상과 열 적외선 영상을 기반으로 객체 탐지 알고리즘을 수행하고 각 영상에 따른 객체 탐지 성능을 비교한다. 야간에 취득한 RGB 영상과 열 적외선 영상에 객체 탐지를 수행하였으며, 열 적외선 영상 기반 결과가 RGB 영상 기반일 때 보다 더 높은 정확도를 보여주었다. 추가적으로 밤 시간대의 RGB 영상과 열 적외선 영상을 선정하여 객체 탐지 네트워크를 튜닝하였으며, fine-tuned 네트워크를 이용하여 객체 탐지한 실험 결과 역시 열 적외선 영상이 RGB 영상보다 더 높은 객체 탐지 정확도를 보이는 것을 확인할 수 있었다.

• Journal of the Korean Regional Science Association
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• v.38 no.3
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• pp.3-17
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• 2022

The automobile-centered lifestyle has provided many advantages to urban residents, but it is also causing various problems. Among them, illegal parking is one of the representative urban problems that negatively affect them. The purpose of this study is to derive the urban environmental factors affecting illegal parking and provide policy implications by using data related to illegal parking among civil complaints about smart inconvenience reports in Seoul in 2019. It was judged that the influencing factors would differ depending on the time of the complaint, and the analysis was conducted by dividing the time of the complaint into a whole day, daytime, and nighttime. As a result of the analysis of this study, it was found that land-use variables and the number of POI facilities were closely related to illegal parking complaints. Also, the subway station area and road width were found to be closely related to illegal parking complaints. On the other hand, parking facilities did not show significant results with illegal parking complaints. This study showed that the use of civic complaint data could be used as important data to identify urban problems that city residents actually experience and to come up with policy implications.

• Geophysics and Geophysical Exploration
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• v.16 no.4
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• pp.203-210
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• 2013

To look into site characteristics of the Hwacheon borehole seismic station, we analyzed property of earthquake and microtremor recorded on surface and borehole seismometers. Acoording to analysis result of microtremor, the surface-to-borehole energy ratio was approximately 15 times greater during the daytime than during the nighttime, and the surface-to-borehole ratios of spectral amplitudes as frequency increases. For earthquake data, amplitude spectra and dominant frequency were computed using surface and borehole data. As a result, small earthquakes with short distance recorded on surface seismometer peaked at 8 Hz, 46 Hz. This result corresponds to resonance frequencies (7.4 Hz, 46 Hz) calculated by H/V spectral ratio. We confirmed amplification effect by site characteristics of overburden. Background noise level was approximately 20,000 times smaller at borehole seismic station than surface seismic station. These results provide strong evidence for the superior recording of earthquakes using borehole seismometers instead of surface seismometers.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.6
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• pp.520-527
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• 2004

This study was carried out to investigate the present state of noise level including three general districts and two roadside areas at the Residential Area such as Sangmu, Pungam, Moonheung, and Ilgok Area. The noise level was measured quarterly. The results were shown that the noise level of day time was no great difference and that noise level of night time represented ranges between 44 to 48 dB(A). The noise level of day time was higher 4 to 7 dB(A) than night time. At the roadside areas, average noise level of day time was suitable to the requirements of environmental criteria. However. only one point of two points exceeded the noise level of environmental criteria. except Pungam Area. The noise level of night time in all areas was 58 dB(A), showing more 3 dB(A) than the environmental criteria (55 dB(A)). The difference of noise level between day time and night time was approximately 5 to 7 dB(A) in all Area. The noise level of day time was not dependent on all seasons, whereas that night time is dependent on season, especially showing lower noise level in winter. Showing the changes on the times in a day, it reached the highest at 16:00, mainly resulting in a lot of activities of people. The maximum noise level (Lmax) from 3 or 4 military aircraft showed almost the same. The noise level of aircraft in Sangmu Area was 71.5∼78.1 WECPNL.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.198-206
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• 2011

Poems written on the tablets hanging in Kwanghanru(a pavilion in Namwon, Jeollabuk-do) reveal each author's view of landscape and their recognition of the pavilion and it surroundings. This study consists of the following four analysis frames of the characteristics, sensations, and temporal and spatial axes of the landscape elements grouping tablet poems into two categories of deunglusi of Joseon's literary men, and baegiljangsi and cheongtaksi of the 1930s. The result of the landscape element analysis shows that physical elements are shown more frequently than symbolic ones. Among the physical ones, natural elements are used more often than artificial ones. The landscape elements appearing in each individual poem of baegiljangsi and cheongtaksi are relatively more than those of deunglusi. When the landscape elements are analyzed by sensational aspect, most of them are visual in nature, and there also appear some that are aural or olfactory in nature. Analyzed from a temporal axis, expressions related to autumn and evening and night are used frequently. From the spatial axis, foreground elements are preferred to middleground or background ones.