• 생물환경조절학회지
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• 제15권3호
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• pp.277-282
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• 2006

천연 살초성분 해발을 위한 기초적 연구로 발아 및 생장억제물질 동정을 위하여 몇 가지 유기용매에 따른 황련의 분획 추출물에 대한 다른 식물의 종자발아 및 유묘생장에 미치는 영향을 조사하였다. 추출물에 대한 검정식물의 발아율은 들깨, 배추, 피, 참깨 순으로 억제되었으며, 2,000ppm ethyl acetate추출물에서 가장 높은 발아억제를 보였다. 초장 및 뿌리생육은 참깨, 들깨, 배추, 피 순으로 억제되었으며, 특히 뿌리신장은 $H_2O$, butyl alcohol, hexane, ethyl acetate 추출물 순으로 억제정도가 심하였다 추출물에 대한 발아 및 유묘생육의 억제정도는 참해 및 배추에서 종특이적으로 작용하였으며, 특히 물 추출물은 종자발아 및 뿌리 신장에 천연살초활성을 보였다. 이러한 결과들은 금후 천연제초제 개발을 위한 기초자료로 이용될 것으로 기대되었다.

• 한국환경복원기술학회지
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• 제8권3호
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• pp.21-32
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• 2005

In Incheon metropolitan city, the urban open space areas are deficient and it is nearly impossible to obtain newly the land for parks by reason of the risk of the land value, the budgetary deficit and so forth. Therefore, it seems to be urgent to consider how to manage the established urban natural park efficiently to enhance the quality of recreational experiences of the public. The organization for the urban natural parks management is to be completely put in good order, for the objects to manage is changeable as well as diverse and what users need should be full satisfied. The purpose of this study is to investigate the differences of urban natural park's management suggest the improvement and development directions in urban natural park by group(professionals and Users). To do this, data were collected in the typical regions by urban natural park for this study, using the questionnaires. In these urban natural park, the on-site survey was carried out the users of these urban natural park during October in 2004. Also The analysis was done with the valid questionnaires of user's 644 and professional's 146. The questionnaires contained three of categories : openspace types' satisfaction and urban natural park's satisfaction, and management, and park user's socioeconomic characteristics and behaviors. Data collected from respondents were analysized by descriptive statistics, T-test, factor analysis and regression analysis. The results of this study can be summarized as follows; The evaluation of urban natural park management is predicted the operation management. So, one can draw a conclusion that user's needs is likely to be increased correspondingly as urban natural park planning and design, management which meets the overall satisfaction. Using the results of this study, we can make a guideline for a park management program, market positioning, standards and provisions of urban natural park by group.

• 한국한의학연구원논문집
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• 제1권1호
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• pp.495-508
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• 1995

In order to search for anti-HSV agents from natural complex products, we extended the number of specimens. Both methanol extract and boiling water extract of the natural complex products were screened to detect anti-HSV activity by MTT assay. Anti-HSV activities of thirteen natural complex products extracted by methanol and boiling water were screened. Three of 13 natural complex products extracted by methanol showed efficacy against HSV. Natural complex products showing anti-HSV activities as methanol extracts were No.3, 6, 11 and their Sl were 323.809, 2811.041 and 708.20. As water boiling extracts, No.8 and No.11 have displayed Sl of 16.45 and 60.39 respectively. Especially anti-HSV activities of natural complex products extracted by methanol No.6 was stronger than other ones.

• Structural Engineering and Mechanics
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• 제7권5호
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• pp.447-456
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• 1999

This paper presents a solution method, which can be regarded as the further extension of the generalized evolutionary method (Zhao et al. 1998a), for the simultaneous optimization of several different natural frequencies of a structure in general and a two dimensional structure in particular. The main function of the present method is to optimize the topology of a structure so as to simultaneously make several different natural frequencies of interest to be of the corresponding different desired values for the target structure. In order to develop the present method, the new contribution factor of an element is proposed to consider the contribution of an element to the gaps between the currently calculated values for the different natural frequencies of interest and their corresponding desired values in a weighted manner. Using this new contribution factor of an element, the most inefficiently used material can be detected and removed gradually from the design domain of a structure. Through applying the present method to optimize two and three different natural frequencies of a two dimensional structure, it has been demonstrated that it is possible and applicable to use the generalized evolutionary method for tackling the simultaneous optimization of several different natural frequencies of a structure in the structural design.

• 소음진동
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• 제8권6호
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• pp.1062-1068
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• 1998

This paper describes the vibration characteristics of a high head pump-turbine runner. with nine blades and an outer diameter of 4.410 mm. of the pumped storage power plant. Mode shapes and natural frequencies were obtained by means of both the finite element analysis and modal testing. both in air and in water. The natural frequencies in air were calculated using the finite element method by ANSYS software. In order to confirm calculation results. the natural frequencies and mode shapes of the runner were measured using a hydraulic exciter both in air and in water. Natural frequencies of the pump-turbine runner were found at 174. 310 Hz in air, and at 107. 184 Hz in water. The first mode shape is flat plate mode with two nodal diameter and the second one is also flat plate mode with three nodal diameter. It can be shown that the natural frequencies of the pump-turbine runner in water is reduced approximately 40 ％ due to additional mass effect. Natural frequencies in air predicted by ANSYS software are in good agreement with test results.

• Structural Engineering and Mechanics
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• 제16권1호
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• pp.17-34
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• 2003

This paper presents a damage assessment procedure applied to periodic spring mass systems using an eigenvalue sensitivity-based method. The damage is directly related to the stiffness reduction of the damage element. The natural frequencies of periodic structures with one single disorder are found by adopting the transfer matrix approach, consequently, the first order approximation of the natural frequencies with respect to the disordered stiffness in different elements is used to form the sensitivity matrix. The analysis shows that the sensitivity of natural frequencies to damage in different locations depends only on the mode number and the location of damage. The stiffness changes due to damage can be identified by solving a set of underdetermined equations based on the sensitivity matrix. The issues associated with many possible damage locations in large structural systems are addressed, and a means of improving the computational efficiency of damage detection while maintaining the accuracy for large periodic structures with limited available measured natural frequencies, is also introduced in this paper. The incomplete measurements and the effect of random error in terms of measurement noise in the natural frequencies are considered. Numerical results of a periodic spring-mass system of 20 degrees of freedom illustrate that the proposed method is simple and robust in locating single or multiple damages in a large periodic structure with a high computational efficiency.

• 대한가정학회지
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• 제45권4호
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• pp.53-59
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• 2007

We need to diversify the colors by natural dyeing for promotion and extention of the natural dyes market, because natural dyestuffs have the limitation the number of the colors to express, compare to synthetic dyestuffs. It was investigated that wool and silk fabrics could be dyed to green colors using natural mugwort and indigo as one of color diversification, in order to express green color that is difficult to be shown by natural dyeing. The mugwort dyebath was prepared to concentration of $25{\sim}100g/l$ using dried mugwort plant and indigo dyebath was prepared to concentration of $5{\sim}20g/l$ using natural indigo powder. Wool fabrics and silk fabrics were dyed to green(GY, G, BG in Munsell color wheel) by two batch methods using the mugwort and indigo dyebaths. the mugwort dyeing was applied at $80^{\circ}C$ for 20minutes and indigo dyeing applied for $5{\sim}7$ minutes in room temperature. The colorfastness to drycleaning and abrasion of the dyed fabrics were shown good as grade 4-5 or 5.

• 광물과 암석
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• 제33권1호
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• pp.65-71
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• 2020

유리 표준물질은 정밀 지구화학 분석법에 필수적으로 이용되는 표준물질이다. 기존의 합성 유리 표준물질의 단점인 자연 암석과의 조성 차이로 인한 높은 불확실성을 보완하기 위해, 자연산 암석을 이용하여 유리 표준물질을 제작하였다. 백두산 흑요암인 NK-B1G 시료는 미세결정이나 포유물 등의 결정을 포함하지 않는 자연 유리질 암석으로, EPMA나 LA-ICPMS 분석 등의 미세분석을 위한 표준물질로서의 적합성을 확인하였다.

• 대한기계학회논문집
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• 제13권3호
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• pp.385-396
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• 1989

본 논문에서는 차륜과 레일의 접촉부에서 발생하는 크리프힘과 크리프모멘트 를 결합시키고 이들이 병진스프링과 비틀림스프핑에 의해서 연성되었을때 생기는 고유진동수의 특성을 차륜과 레일의 직교성을 이용하여 수치해석하고 모델실험을 통하여 연구하였다.

• Ecology and Resilient Infrastructure
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• 제6권1호
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• pp.49-57
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• 2019

본 연구에서는 북한의 생태계와 국토 관리에 대한 문제를 해결할 수 있는 법적 체계를 수립하는데 도움을 주기 위하여, 자연환경과 사회기반시설에 대한 북한의 법령을 종합적으로 분석하였다. 북한의 헌법에서 환경권은 자연환경 보전의 측면이 강조되어 있다. 북한에서는 자연환경과 국토 관리에 대한 법령은 비교적 통합적으로 제정되어 있었다. 자연환경 관리에서 자연보호지역 설정을 중심으로 생태계 보전이 이루어지고 있다. 국토관리에서는 사회기반시설에 대한 우선순위가 강조되고 있다. 북한의 자연환경과 국토 관리에 대한 선진적인 법 체제 구축과 법 집행의 성과를 거두기 위하여 경제적, 기술적 지원이 요청된다.