• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.8 no.3
• /
• pp.21-32
• /
• 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.

• Korean Journal of Oriental Medicine
• /
• v.1 no.1
• /
• pp.495-508
• /
• 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
• /
• v.7 no.5
• /
• pp.447-456
• /
• 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.

• Journal of KSNVE
• /
• v.8 no.6
• /
• pp.1062-1068
• /
• 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
• /
• v.16 no.1
• /
• pp.17-34
• /
• 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.

• Journal of the Korean Home Economics Association
• /
• v.45 no.4
• /
• pp.53-59
• /
• 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.

• Korean Journal of Mineralogy and Petrology
• /
• v.33 no.1
• /
• pp.65-71
• /
• 2020

Glass reference materials have been essentially used for precise geochemistry analytical techniques. In order to make up for the drawback of synthetic glass reference materials, which have the high uncertainty caused by the difference in composition of natural rocks, we introduce a glass geostandard using natural glass. The NK-B1G sample, which comes from the Baekdusan obsidian, is a natural glassy rock that contains only few crystals such as microlites or inclusions. We examined the feasibility of the sample as a reference material for microanalysis like EPMA or LA-ICPMS.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.13 no.3
• /
• pp.385-396
• /
• 1989

In this paper, using by the orthogonalities of modes for trainwheel (as Mindlin's annular plate and rail (as Timoshenko beam), the frequency equation of the coupled system are induced. It is convinced that the natural frequencies of coupled system are distributed to be about quadratic order function examined through the experimental and numerical analysis. The natural frequencies of the system coupled by both creep force and creep moment are composed of the natural frequencies of the system coupled by creep force and the natural frequencies of the system coupled by creep moment . And it is shown that the coupled natural frequencies up to 3rd do not make much difference from the values of the system coupled by individual creep force of creep moment. But the coupled natural frequencies higher than the 3rd are quite different from those of individual case.

• Ecology and Resilient Infrastructure
• /
• v.6 no.1
• /
• pp.49-57
• /
• 2019

The North Korean laws on natural environments, land and infrastructure were comprehensively analyzed in order to help establish the legal system to solve problems of ecosystem and land management in North Korea. The citizen's environmental rights in North Korean Constitutional Law emphasize the aspect of conservation of the natural environments. The laws on the managements of natural environments and land are relatively integrated in North Korea. In the management of natural environments, ecosystem conservation is centered on designation of natural protected areas. Priority for infrastructure construction is emphasized in land management. The economic and technical support is needed to build advanced legal systems for the conservation of natural environments and ecological land management and to improve their performance of law enforcement.

• International Journal of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.189-197
• /
• 2022

Today, we are exposed to various text-based media such as newspapers, Internet articles, and SNS, and the amount of text data we encounter has increased exponentially due to the recent availability of Internet access using mobile devices such as smartphones. Collecting useful information from a lot of text information is called text analysis, and in order to extract information, it is performed using technologies such as Natural Language Processing (NLP) for processing natural language with the recent development of artificial intelligence. For this purpose, a morpheme analyzer based on everyday language has been disclosed and is being used. Pre-learning language models, which can acquire natural language knowledge through unsupervised learning based on large numbers of corpus, are a very common factor in natural language processing recently, but conventional morpheme analysts are limited in their use in specialized fields. In this paper, as a preliminary work to develop a natural language analysis language model specialized in the railway field, the procedure for construction a corpus specialized in the railway field is presented.