• Journal of the Korean housing association
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• v.22 no.1
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• pp.43-55
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• 2011

The purpose this study is to develop indicators that measure the healthy housing condition of multi-family housing. The major findings are as follow: first, healthy housing was defined by physical, mental, social, and management aspects and proposed the conceptual model of hierarchy structure of evaluation of healthy housing by literature reviews. Second, evaluating items were selected based on literature reviews of existing indicators and preceding studies about both domestic and overseas multi-family housing. The evaluating indicators were identified as a total of 87 evaluating items which were composed of four dimensions and 16 attributes on the basis of the conceptual model. They cover comprehensive scope of the multi-family housing such as unit, building, complex, and site. Third, as the measurement, the 5-point ordinal scale measure was suggested. The evaluating measurement including measure standards, measure methods, and measure contents were developed by each evaluating items. Lastly, the weighting of evaluating indicators was developed by AHP method conducted by survey of an expert group. Items were identified as high contributors or low contributors. The weighting of these items could suggest several evaluations according to the situation. The level of healthy housing condition may be evaluated by both total evaluation and a specific field of evaluation.

• Land and Housing Review
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• v.10 no.3
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• pp.67-75
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• 2019

The modular construction means that more than 70% of the parts such as walls, windows, electrical wiring, facility piping, bathrooms, and kitchen appliances are pre-assembled at the factory and transported to the site. It is possible to shorten the construction period than general construction work and to secure high quality through modular mass production since the modular construction works in the field at the same time as the modular production. However, there are only four domestic modular manufacturers, and each company's modular components and construction methods are different, so it is necessary to standardize them. Therefore, this study investigated the construction process centering on the stacking method of modular housing construction work applied to D site in Cheonan-si, and proposed the key points of quality management by construction stage. As the project was conducted as a pilot project for government R&D projects, some differences may occur from general modular housing construction. However, the construction process and quality control focus of each unit box type modular house analyzed in this study can be used as basic data in the future of modular housing construction. In addition, the results of this study can be used to establish construction standards, such as the development of checklists and establishment of standard processes.

• Journal of the Korean housing association
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• v.10 no.1
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• pp.137-144
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• 1999

This study examines the general reuse plan for deteriorated multi-family housing (apartrtments) in the urban fringe of Taegu City. The apartments which were built in the 1970's have to be improved. It is necessary to carry out the actual investigation for alternatives of reconstruction or reuse. From the above point of view, the study lays its purpose to find pertinent directions for the reasonable reuse plan, and gets on as follows; 1) Analize the residential state for users' needs of detoriorated aprtments through an investigation. 2) Synthesize the experts' opinions about matters related to reuse planning through a questionnaire. 3) Suggest the general solutions in three areas; unit dwelling, housing site, equipment and facilities, Finally, in the future housing development projects, concepts of reuse planning should be reflected beforehand.

• Proceedings of the Korean Geotechical Society Conference
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• 1995.10a
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• pp.15.2-22
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• 1995

Evaluating stiffness of near-surface materials has been one of the critically important tasks in many civil engineering works. It is the main goal of geotechnical characterization. The so-called deflection-response method evaluates the stiffness by measuring stress-strain behavior of the materials caused by static or dynamic load. This method, however, evaluates the overall stiffness and the stiffness variation with depth cannot be obtained. Furthermore, evaluation of a large-area geotechnical site by this method can be time-consuming, expensive, and damaging to many surface points of the site. Wave-propagation method, on the other hand, measures seismic velocities at different depths and stiffness profile (stiffness change with depth) can be obtained from the measured velocity data. The stiffness profile is often expressed by shear-wave (S-wave) velocity change with depth because S-wave velocity is proportional to the shear modulus. that is a direct indicator of stiffiiess. The crosshole and downhole method measures the seismic velocity by placing sources and receivers (geophones) at different depths in a borehole. Requirement of borehole installation makes this method also time-consuming, expensive, and damaging to the sites. Spectral-Analysis-of-Surface-Waves (SASW) method places both source and receivers at the surface, and records horizontally-propagating surface waves. Based upon the theory of surfacewave dispersion, the seismic velocities at different depths are calculated by analyzing the recorded surface-wave data. This method can be nondestructive to the sites. However, because only two receivers are used, the method requires multiple measurements with different field setups and, therefore, the method often becomes time-consuming and labor-intensive. Furthermore. the inclusion of noise wavefields cannot be handled properly, and this may cause the results by this method inaccurate. When multi-channel recording method is employed during the measurement of surface-waves, there are several benefits. First, usually single measurement is enough because multiple number (twelve or more) of receivers are used. Second, noise inclusion can be detected by coherency checking on the multi-channel data and handled properly so that it does not decrease the accuracy of the result. Third, various kinds of multi-channel processing techniques can be applied to f1lter unwanted noise wavefields and also to analyze the surface-wavefields more accurately and efficiently. In this way, the accuracy of the result by the method can be significantly improved. Fourth, the entire system of source, receivers, and recording-processing device can be tied into one unit, and the unit can be pulled by a small vehicle, making the survey speed very fast. In all these senses, multi-channel recording of surface waves is best suited for a routine method for geotechnical characterization in most of civil engineering works.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1259-1267
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• 2023

In recent years, as the demand for distributed power has increased, the need for microgrids connected to grid power and renewable power generation sources has emerged. In the case of DC microgrids, reactive power does not occur, and power conversion losses are reduced compared to AC when connecting to the load and power grid[2]. With the revitalization of the DC distribution network industry, various studies and demonstrations of DC microgrids have been carried out. In the case of the recent unit distribution, its stability and effectiveness have been verified through empirical and research analysis. However, there is a lack of empirical tests to prevent chain accidents for the protection of the power grid circuits and the misoperation of the distributed power system caused by individual accidents when connecting various distributed power sources and power grids. In this paper, the operation plan of a stable multi-circuit DC distribution connection for the demonstration site was verified through the protection cooperation and operation algorithm for the stable linkage management of the DC distribution network composed of such a multi-circuit.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.2
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• pp.107-111
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• 2011

The release of a site and building from regulatory control is the final stage of the decommissioning process. The MARSSIM (Multi-Agency Radiation Survey and Site Investigation Manual) provides overall framework for conducting data collection for a final status survey to demonstrate compliance with site closure requirements. The KAERI carried out establishing a final status survey by using the guidance provided in the MARSSIM for of a site and building of the Korea Research Reactor. The release criteria for a site and building were set up based on these results of the site specific release levels which were calculated by using RESRAD and RESRAD-Build codes. The survey design for a site and building was classified by using the survey dataset and potential contamination. The number of samples in each survey unit was calculated by through a statistical test using the collected data from a scoping and characterization survey. The results of the final status survey were satisfied the release criteria based on an evaluation of the measured data.

• Animal Bioscience
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• v.34 no.6
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• pp.985-992
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• 2021

Objective: Artificial insemination plays an important role in genetic improvement in the goat farming system. The aim of this study was to investigate the effect of cervical application of hyaluronan (HA) on the fertility in goats after cervical artificial insemination using frozen-thawed (F-T) semen. Methods: After oestrous synchronisation with progesterone sponges and pregnant mare serum gonadotropin injection, both nulli- and multi-parous goats, were randomly allocated to 2 groups, and were inseminated with 0.25 mL of F-T semen (150×106 spermatozoa) twice at 52 h and 56 h after sponge removal. Prior to the insemination, goats in Group 1 only were given topical cervical HA application at 48 h after sponge removal. Site of insemination was recorded as os-cervix or intra-cervix or intra-uterus. Pregnancy was tested ultrasonographically 42 days after insemination. The data on pregnancy rates and percentage of animals according to the site of semen deposition were compared by Chi-square analysis. Results: The overall pregnancy rate was significantly (p<0.004) higher in goats with prior application to the cervix with HA (63.3%) than without (36.0%). Same pattern was observed in the pregnancy rates of nulli- and multi-parous goats in both the groups. Percentage of nulliparous goats according to the site of insemination in the HA group did not differ between first and the second insemination. However, in multiparous goats the percentage of animals inseminated intra-cervically was significantly increased (p≤0.05) between the first and the second inseminations. Conclusion: The results suggest that significantly higher fertility rate in the "HA goats" compared to the "without HA" group was because of deeper insemination facilitated by topical cervical application of HA. The deeper insemination into the cervical canal increase the rate of fertilisation when the cervical artificial insemination is performed.

• Journal of Korean Society of Rural Planning
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• v.3 no.2
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• pp.36-49
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• 1997

The drastic change of mountain community, which have led existing villages to a size reduction or an extinction, makes this study concentrate on finding out the new community unit as a spatial zone of dayily life and agricultural production. The communality which has played a key role in a aura settlement consistency has been focused on the socio-economic aspect till now, neglecting the spatia] nature. The settlement-communality( SC) putting a stress on the spatial aspect can be, therefore, shapec as being multi-dimensional, composed of both a horizontally areal coverage on the surface of the residential place and a vertically hierarchial relationship between settlements, by analyzing thro( elements of communality that are the economic, socio -cultural and spatial activities. The research site is located administratively in Milan-Myoun, Pyoungchang-Gun, Gangwon-Do that ha: the characteristics as a typical mountain community. The results of field survey of which the method i: to draw the activity zone from an interview with every village's head and some residents with th( prepared questionaire can be summarized as followings. Firstly, the SC in almost all villages tended to be weakened or extincted, none the less, the spatia zone of that overally enlarged and got out of natural village unit(hamlet). However the areal coverall on which the SC has an influence reaches up to the alliant domain of a few villages generally congruen with the lowest level administrative district, Secondly, the economic and social activity pattern in village life has a tendency to be directly linked with a upper central place, so that has induced the function of a central village in the middle-low settlement hierarchy to be largely shrinked. Not only the conventional residents'access to goods service but also the recent service-delivers'access to residents has gradually formed the vertical communality with direct linkage between the upper and the bottom level settlements Lastly, the enfeeblement of the SC in the lowest settlement level tends to be supplemented by enlarging the horizontal zone of the SC or especially by strengthening the vertical direct linkage system. The very this point makes the mountain community open to the external world and also makes the spatial unit of community be multi-dimensional just like a cubic.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.10
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• pp.1001-1007
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• 2013

In the case of multi-mission LEO(Low Earth Orbit) operations, depending on the orbit of each satellite, one ground site is supposed to be communicated with more than two satellites at the same time. On top of that, image data processing system is generally mission-specific and 1:1 backup configuration. For the reason, if ground site has smaller number of antenna than that of satellite, interface with image data processing system would be very complicated. In this paper, considering that two LEO satellites can be operating and image data recording unit in redundancy can be easily plug-in, the implementation of matrix receiving structure is described. This matrix receiving structure has been validated from KOMPSAT-2 and -3(KOrea Multi-Purpose SATellite-2 and -3) since KOMPSAT-3 was launched in May, 2012. This structure will be applied for the KOMPSAT-3A and -5 through its expandability.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.2
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• pp.75-86
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• 2004

This study aims to figure out ecological characteristic of natural forests focusing on vegetation as a way of ecological renovation for the restoration of naturalness for golf courses that were constructed in the Country and to present vegetation models and appropriate tree species for the purpose. The study site is P golf club, which is located in Gapyong-gun, Kyeonggi Province. The site is within a forest where the grade from the natural ecology map is the first one and the level from the green index accounts for the eight, thus showing a typical environment for a golf course in terms of location. The location of the site explains a reason for restoration. The major substance of the study is to conduct ecological evaluation of vegetation structures around and inside the golf course and to present a vegetation model. In order to evaluate the ecological characteristics of the vegetation structures, the analysis of the study covered succession stages, multi-layer vegetation structures and species diversity. Plant communities that have high species diversity were selected for the vegetation model and proper density and species were proposed considering the number of species and individuals and distances between trees. The vegetation restoration model targets succession into an oak forest. Within a unit of 100 $m^2$, the recommended model include a tall-tree layer with 11 trees such as Quercus serrata and Quercus mongolica, a sub-tall-tree layer with 12 trees including Quercus mongolica, Quercus serrata, Prunus sargentii, Fraxinus rhynchophylla and Acer pseudo sieboldianum, a shrub layer with 32 trees from 16 species, and a grass layer with a cover rate of 45 %. The proposed vegetation restoration model needs to apply to : 1) damaged natural forests by the construction of golf courses; 2) boundaries between golf courses and surrounding forests; 3) buffer zones; 4) open spaces in between courses; and 5) areas between greens and tees where open spaces are available in a mass. In conclusion, one of the most important factors in presenting a vegetation model for the restoration of naturalness in the golf course and other damaged forests is to provide multi-layer vegetation structures that are composed of native species. As for the specific application for the site, it is recommended to manage the vegetation in such a way that the environment of the site can have a similar environment to the surrounding forest which is expected to succeed into an oaks-dominant one.