• Hwankyungkyoyuk
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• v.3 no.1
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• pp.55-62
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• 1992

In the orient, ancestor's perception to natural environment was related on the change of climate. Man had been a essence of the warm blood animal, which had suited in mild climate for living and acting. The weather of hot or cold was not only comfort in human life but influences negatively on human behavior. The most people of oriental was particularly interrelated to seasonal change of climate in earlier time. Because, there are elements such as temperature, humidity and wind in the category of climate, these elements differentiated seasonal change. The main methods of perception of natural environment were observed and classified. Although these methods were in the primitive stage, these coincided the tendency of modern science. For example, confucian was recognized the law of vertical air current that warm air rised and cold air sinked. And they could classify all elements nature based on the principles of 'Yin and Yang(陰陽論)' such as male and female, the sun and moon. shade and light etc. Thus results of the observation and the classification concerned with physical environment can be utilize a wisdom for progressive life of inhabitants. It was a origin of the education in natural environment. Commonness in the viewpoint of environment in the orient if recognized the law of circulation. Buddhism, originated in india, realized that all of phenomena in the world was changed slowly through the principles of cycle(輪廻說) such as male and female, the sun and moon, shade and light etc. Thus results of the observation and the classification concerned with physical environment can be utilized a wisdom for progressive life of inhabitants. It was a origin of the education in natural environment. Commonness in the viewpoint of environment in the orient if recognized the law of circulation. Buddhism, originated in India, realized that all of phenomena in the world was changed slowly through the principles of cycle(輪廻說). For example, whole of land is shifted from young stage to old stage as the life cycle of humanbeing. The theory of karma effects(葉報設) is so signify with the good result that good one's action is reap a sweet fruit. The most environmental problem in today must realized as a consequence of men's act. Then Taoism emphasized the pure nature without the artificiality. Because complexual environment was composed of several elements, It was maintained through the artificiality. Because complexual environment was composed of several elements, It was maintained through the interaction of cause and effects. The solution of environmental problem is maintenanced the harmony between cause and effects by a philosophical concept.

• Journal of Environmental Science International
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• v.23 no.2
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• pp.261-274
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• 2014

This work investigates the relationship between the sea breeze circulation and ozone concentrations during cold water events in the southeastern coastal area of the Korean Peninsula, where coastal upwelling frequently occur. This analysis was performed based on the classification of two categories, such as cold water and non-cold water events, over the period of 2000-2009. The low air temperature ($0.5^{\circ}C$), low SST ($5^{\circ}C$) and the wind direction(southerly) are the features of the cold water events in the Southeastern coastal area. Moreover, ozone concentrations in the cases of the sea breeze circulation and cold water events were significantly lower (below 30 ppb) than those (70~100 ppb) in the non-clod water events, because of the low air temperature ($10{\sim}20^{\circ}C$) and high wind speed (3~5 m/s) around the southeastern coastal area.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.61-69
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• 2018

In this paper, we propose a method for recognizing ground target using dual polarization channels in millimeter waveband air-to-surface radar. First, the Push-Broom target detection method is described and the received signal is modeled considering flight-path scenario of air-to-surface radar. The scattering centers were extracted using the RELAX algorithm, which is a time domain spectral estimation technique, and the feature vector of the target was generated. Based on this, a DB for 4 targets is constructed. As a result of the proposed method, it is confirmed that the target classification rates is improved by more than 15% than the single channel using the data of the dual polarization channel.

• Explosives and Blasting
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• v.20 no.3
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• pp.25-38
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• 2002

터널 굴착선 여굴(Overbreak)은 발파공법에 의한 괄착 중에 필연적으로 발생하는 현상으로서 숏크리트, 라이닝 등의 보강비 추가 발생과 버력 처리량의 증대로 공기 및 공사비를 증가시키는 주요한 요인으로 작용한다. 또한 터널 굴착선 암반의 손상으로 균열층이 형성되거나 부석이 발생하여 안전문제를 야기시키기도 한다. 이러한 여굴 발생은 천공오차, 발파패턴의 오류, 잘못된 화약선정, 불규칙한 암반 특성 등에 그 원인이 있으나, 지금까지 터널 여굴은 천공 및 발파기술에 의해 좌우된다라는 인식이 대부분이었다. 그러나 여굴 발생에 중요한 원인으로 터널 굴착선 암반의 특성과 이에 적합한 발파패턴 및 화약류를 들 수 있다. 본 연구는 여굴 발생에 영향을 미치는 암반상태를 파악하기 위해서 터널 굴착선 주변암반의 균열정도, 강도, 불연속면의 간격, 방향, 간극, 충전물 상태 등의 6가지 요소를 이용하여 암반을 분류하는 발파암 분류법(BI)을 새로 제안하였고, 이 분류에 따라 외곽 공의 간격과 장약밀도를 달리 하는 발파패턴을 정립하였다. 또한 화약의 순폭도와 Air Deck 효과를 이용하여 장약밀도를 조절할 수 있는 N.D.C(New Deck Charge) 발파공법을 개발함으로써 여굴을 최소화할 수 있었다.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.602-608
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• 2020

PRAIRIE(Propeller Air Induced Emission) system is a kind of underwater radiated noise suppression systems to reduce the probability of the identification or classification of our warship's acoustic signature by an enemy ship. It is effective in case of strong cavitation events. This is because air bubbles emitted from the PRAIRIE system mitigate drastic collapses of the cavity bubbles that can generate an intense shock wave. However, when the PRAIRIE system is operated in a non or weak cavitation condition, it might increase the total level of underwater radiated noise and induce the acoustic signatures. Therefore, this paper presents the trial results on ventilation control of PRAIRIE to find a more efficient operation depend on the cavitation condition. Then, we show a variation of the amplitude modulation characteristics according to ventilation control.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.1
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• pp.82-87
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• 2005

The purpose of this study is to suggest the characteristics and actual state of energy consumption by the analysis of energy consumption data in an office building. This study examines and analyzes daily and monthly energy consumption of an office building located in Seoul, Korea regarding type of load and business classification within a building. The results are as follows. 1) Energy consumption of office building for each type of load show similar consumption patterns, regardless of seasons such as cooling period and heating period. 2) Out of all annual energy consumption, consumption for lighting took about $43\;\%,$ general electric Power about $23\;\%,$ emergency power $25\;\%,$ computer center $5\;\%$ and cooling power $4\;\%,$ showing that the consumption for lighting was highest, and the percentage of energy consumption for cooling power for operation of cooling facilities took the lowest percentage. 3) Annual gas consumption used for heating and hot water supply were $38,\;36\;\%$ for officetel and office respectively, and $26\;\%$ for arcade. 4) Electricity consumptions used for cooling power for each use of building, office and officetel recorded in July and August of cooling seasons. Even though it shows different patterns for each month, energy consumption showed unique pattern throughout the cooling seasons.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.357-358
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• 2013

본 논문에서는 커패시턴스를 이용해 수액 내에 있는 공기방울을 검출하고 수액의 성분을 구분 할 수 있는 측정기의 원리에 대해 제시해보려 한다. 이 측정기의 원리는 유전율의 변화를 감지하여 수액의 종류를 판단하고, 수액 내부의 기포를 검출해내는 등 의원성 사고를 근본적으로 막는 데에 그 의의가 있다. 실험결과 본 연구에서 제작한 측정기로 수액에 따른 값의 차이를 확인하였고, 발생한 기포에 대한 출력 결과를 확인할 수 있었다. 본 연구를 통해 커패시턴스 차폐의 정도가 결과의 신뢰도 측면에 중요한 요인으로 작용하고 있음을 확인 할 수 있었다. 향후 외부 간섭에 따른 노이즈에 대한 추가적인 커패시턴스 차폐 연구가 필요한 것으로 판단된다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.4
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• pp.358-363
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• 2012

The simulation investigation on the availability of LNG plant with scenario of failure events and failure rate has been carried out. This study focuses on the availability, productivity, criticality induced by failure rate of major equipment. The methodologies for simulation such as the equipment classification of LNG plant and failure type and event schematic are established. The availability and mean time to repair have second order function profile in the all cases except general equipment, but these profiles have different inclination. The production and criticality of the specified LNG plant, simulated by Monte-Carlo algorithm, is located in the range of P = 86~92% and PL = 6~13%.

• The Journal of Korean Institute of Information Technology
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• v.17 no.9
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• pp.11-17
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• 2019

In recent years, damage and loss of life and property have been occurred frequently due to swelling waves in the East Sea. Swelling waves are not easy to predict because they are caused by various factors. In this research, we build a model for predicting the swelling waves occurrence in the East Coast of Korea using machine learning technique. We collect historical data of unloading interruption in the Pohang Port, and collect air pressure, wind speed, direction, water temperature data of the offshore Pohang Port. We select important variables for prediction, and test various machine learning prediction algorithms. As a result, tide level, water temperature, and air pressure were selected, and Random Forest model produced best performance. We confirm that Random Forest model shows best performance and it produces 88.86% of accuracy

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.4
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• pp.1-20
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• 2021

Due to the recent rapid increase in passenger and cargo air transport demand, the capacity of Jeju International Airport has been approaching its limit. Even though in COVID-19 crisis which has started from Nov 2019, Jeju International Airport still suffers from strong demand in terms of air passenger and cargo transportation. However, it is an undeniable fact that the delay has also increased in Jeju International Airport. In this study, we analyze the correlation between weather and delayed departure operation based on both datum collected from the historical airline operation information and aviation weather statistics of Jeju International Airport. Adopting machine learning techniques, we then analyze weather condition Jeju International Airport and construct a delay prediction model. The model presented in this study is expected to play a useful role to predict aircraft departure delay and contribute to enhance aircraft operation efficiency and punctuality in the Jeju International Airport.