• Journal of Forest and Environmental Science
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• 제38권4호
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• pp.290-301
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• 2022

Increasing life expectancy leads to a rise in the prevalence of aging-related mental diseases and a concomitant increase in the financial and societal pressures related to their prevention and management. This issue is attracting increasing attention from researchers. Therefore, this study aimed to determine whether a healing program in a forest environment is effective for improving cognitive function, depression, anxiety, and stress in elderly people. A nonequivalent control group pretest-posttest design was used. The experimental group consisted of 18 males and females aged 60 to 80 years who participated in a forest healing program for seven days, while the comparison group comprised 10 people with similar demographics. For the process of data analysis, this study performed a cross-analysis to determine the homogeneity of the data and carried out the Wilcoxon signed-rank test, a nonparametric statistical test, to verify the significance of each group. Participation in the forest healing program led to a significant improve-ment in cognitive function (p=0.030). The levels of depression decreased, but this result was not statistically significant. The levels of anxiety decreased significantly (p=0.004). The mean cortisol score, a measurement of stress, decreased, but it was not statistically significant. These findings confirmed the effectiveness of this program for improving certain mental conditions of elderly people, and affirmed that the use of long-term forest healing programs can be expected to alleviate national pressures created by aging societies.

• 태양에너지
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• 제13권2_3호
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• pp.5-11
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• 1993

이 논문은 최근들어 보급이 확대되고 있는 아트리움(Atrium)을 이용한 건물에 있어서, 아트리움의 가장 기본적 인 기능인 에너지절약 효과와 환경조절효과가 거의 실효를 거두지 못하고 오히려 환경의 악화와 에너지소비 증가로 나타나는 점을 고려하여, 아트리움의 환경조절기능에 대한 기초사항을 체계적으로 정리하고 에너지절약 성능을 정량적으로 분석하여 건축설계시 적용할 수 있는 아트리움의 설계기법을 제시함으로써 아트리움을 통한 건물의 에너지절약 효과를 극대화하고 쾌적환경을 조성하는 기초자료를 제공하고자 한다.

• 제어로봇시스템학회논문지
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• 제15권7호
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• pp.720-727
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• 2009

This paper proposes a new integrated navigation system for a mobile robot in indoor environments. This system consists of five frameworks which are classified by function. This architecture can make the navigation system scalable and flexible. The robot can recover from exceptional situations, such as environmental changes, failure of entering the narrow path, and path occupation by moving objects, using the exception recovery framework. The environmental change can be dealt with using the probabilistic approach, and the problems with the narrow path and path occupation are solved using the ray casting algorithm and the Bayesian update rule. The proposed navigation system was successfully applied to several robots and operated in various environments. Experimental results showed good performance in that the exception recovery framework significantly increased the success rate of navigation. The system architecture proposed in this paper can reduce the time for developing robot applications through its reusability and changeability.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2002년도 춘계학술대회
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• pp.285-294
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• 2002

This study is focused on the operation of truck with conscious for environmental logistics system to reduce empty truck movements, and to control running empty truck. With the logistics function, road transport represents the biggest environmental threat. Using nonrenewable natural resources, contributing to air and noise pollution, trucks are environmentally unfriendly. Any steps to reduce transport activity will help minimize negative impact. In particular, noxious emissions must be reduced, but in the long term more environmentally friendly vehicles are required.

• 한국토양비료학회지
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• 제41권2호
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• pp.143-152
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• 2008

농업이 가지고 있는 환경보전기능에 관한 내재적 가치를 공유하기 위하여 논농사와 밭농사에서 홍수조절기능과 수자원함양기능에 대한 계량화와 대체법을 이용한 경제적 가치를 평가하였다. 논농사에서 홍수조절기능은 논둑높이와 홍수기간 투수되는 물의 양을 더해 추정하였으며 밭농사의 경우는 홍수기 강우량에서 유출량을 제하고 남은 물의 양을 홍수조절량으로 설정하였다. 설정된 추정모형을 기초로 하여 관련 자료를 분석한 결과 논농사는 $294mm\;year^{-1}$, 밭농사는 $72.6mm\;year^{-1}$로 산출되었으며 2006년 기준으로 우리나라 농업의 전체 홍수조절량은 년간 37.1억 톤으로평가되었다. 이 물량을 기준으로 댐건설비와 유지비로 대체하여 경제성 분석을 수행한 결과 논농사는 44조 3,389원, 밭농사는 7조 2,215억원으로 평가되었다. 기존 보고된 결과들과 비교하였을 때 근래 댐건설비의 상승된 요인으로 평가액이 크게 상승한 것으로 분석되었다. 수자원함양기능을 계량화가기 위하여 논농사의 경우는 평균 담수심에 담수기간동안 투수된 물량을 더하고 지하로 유입되는 비율을 곱하여 산정을 하였으며 밭농사의 경우는 포화수리전도도에 투수될 수 있는 기간을 곱하고 여기에 지하로 유입되는 비율을 곱하여 추정할 수 있는 모형을 설정하였다. 설정된 추정모형을 근거로 하여 관련 자료를 분석한 결과 논농사와 밭농사에서 각각 $414.3mm\;year^{-1}$, $18.7mm\;year^{-1}$로 수자원함양량이 산출되었다. 산출된 수자원함양량을 2006년을 기준으로 우리나라 논농사와 밭농사 전체에 적용한 결과 각각 44.9억 톤과 1.34억 톤으로 추정되었다. 수자원함양기능은 지하수 자원과 관련되어 있기 때문에 정수된 물의 단가를 기준으로 금액화를 하였는데 2006년을 기준으로 하였을 때 논농사와 밭농사가 각각 1조 7694억원, 528억원으로 평가되었으며 기존 보고와 유사한 결과를 보여주고 있었다. 홍수조절기능과 수자원함양기능은 논농사와 밭농사의 재배양식의 차이로 인해 산출량과 가치에 있어 크게 차이가 있었으며 논둑을 조성하여 항상 물을 가두고 작물을 재배하는 논농사가 밭농사보다 훨씬 크다는 것을 알 수 있었다.

• 전기학회논문지P
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• 제65권3호
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• pp.171-177
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• 2016

Noise problem that occurs in living environment is a big trouble in the economic, social and environmental aspects. In this paper, the filtered-X LMS algorithms, the adjoint LMS algorithms, and the robust adjoint LMS algorithms will be introduced for applications in active noise control(ANC). The filtered-X LMS algorithms is currently the most popular method for adapting a filter when the filter exits a transfer function in the error path. The adjoint LMS algorithms, that prefilter the error signals instead of divided reference signals in frequency band, is also used for adaptive filter algorithms to reduce the computational burden of multi-channel ANC systems such as the 3D space. To improve performance of the adjoint LMS ANC system, an off-line measured transfer function is connected parallel to the LMS filter. This parallel-fixed filter acts as a noise controller only when the LMS filter is abnormal condition. The superior performance of the proposed system was compared through simulation with the adjoint LMS ANC system when the adaptive filter is in normal and abnormal condition.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.314-324
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• 2020

Due to the nonlinearity and environmental uncertainties, the design of the ship's steering controller is a long-term challenge. The purpose of this study is to design an intelligent autopilot based on Extended Kalman Filter (EKF) trained Radial Basis Function Neural Network (RBFNN) control algorithm. The newly developed free running model scaled surface vessel was employed to execute the motion control experiments. After describing the design of the EKF trained RBFNN autopilot, the performances of the proposed control system were investigated by conducting experiments using the physical model on lake and simulations using the corresponding mathematical model. The results demonstrate that the developed control system is feasible to be used for the ship's motion control in the presences of environmental disturbances. Moreover, in comparison with the Back-Propagation (BP) neural networks and Proportional-Derivative (PD) based control methods, the EKF RBFNN based control method shows better performance regarding course keeping and trajectory tracking.

• 생태와환경
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• 제35권4호통권100호
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• pp.266-272
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• 2002

팔당호에 설치된 인공식물섬에서 미생물의 역할을 알아보기 위하여 동물플랑크톤 군집 크기, 총세균수, 활성세균수, ${\beta}$-glucosidase와 phosphatase의 체외효소활성도를 2001년 11월 3일부터 2002년 4월까지 격주로 인공식물섬이 설치된 지역과 바깥지역을 대상으로 조사 분석하였다 인공식물섬 아래에서는 일반적으로 측정하는 환경요인들은 대조구보다 수질이 나쁜 것으로 나타났다. 그러나, 동물 플랑크톤의 수는 대조구보다 굉균 25배, 활성세균의 수는 평균 3-8배, 그리고 체외효소활성도는 훨씬 높은 값을 보였다. 이러한 결과는 인공식물섬에서는 동물플랑크톤-식물플랑크톤-수초-세균의 밀접한 관계가 존재하고, 이 관계에 의하여 동물플랑크톤과 세균의 호흡, 분해작용으로 유기물이 제거되는 것으로 판단되었다.

• 한국컴퓨터정보학회논문지
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• 제23권3호
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• pp.9-16
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• 2018

In this paper, I purpose one of the development methods for portable Automatic field Test Equipment(ATE) with VME form factor. Almost portable ATE have not used to standards form factor and they are connected by mechanical non-rigid general connectors and wire harnesses among the components. Furthermore, it is hard to reuse developed board. So, it decreases to reusability of developed board and it is hard to maintenance of ATE. Even those things have weakness for vibration and drop test especially in portable ATE. The XK9A1 ATE using VME form factor has environmental reliability through vibration, drop, temperature test. It consists of 5 developed board called the control board, the wire & wireless communication board, the power supply board, the load board and the mother board. It is connected by two wire harnesses between mother board and extern circular connectors. The control board send the data and address to other board though each 16-bit data and 20-bit address line. You can develop the function board what you want to using those data & address line when it comes to needing other function board.

• 대한안전경영과학회지
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• 제5권2호
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• pp.199-214
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• 2003

With the progress of industrial technology, industrial machinery and home appliances have multi-function and high performances by the electronic control technology. Various results are given from the measuring switching induction noise according to environmental condition and its effects cannot be predicted accurately. Therefore, the output results should be analyzed and applied to practical work. To minimize the false operation, Taguchi Method used to solve the quality problem is adopted to analyze the characteristics within the constrained measuring level.