• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.109-114
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• 2009

The dominant heating system used in Korean residential apartment buildings is a hydronic radiant floor heating system, known as the Ondol system. The most common control strategy applied to this traditional hydronic radiant system is a simple on-off control that intermittently supplies "hot water of a fixed temperature" at a "constant flow rate" to each room. However, the current problems with the aforementioned control are as follows: (1) since the simple on-off control is usually based on a one point measured temperature (a signal from a thermostat installed in a living room) in each dwelling unit, heating energy use for unoccupied rooms as well as a difference in temperatures between spaces (master bedroom, living room, bedroom1, bedroom2) can occur occasionally. (2) the most widely used residential water splitter has static valves, and is thus not able to change the flow rate to each room depending on the space heating load. In other words, the ratio of flow rates to rooms is fixed after construction, resulting in over- or under-heating and an improper use of energy. The aim of this paper is therefore to investigate the differences in the system's performance between control strategies in terms of the flow rate control and sensor location. It is shown that energy savings of control strategies are strongly influenced by occupant schedule.

• Journal of the Korean housing association
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• v.24 no.6
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• pp.141-150
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• 2013

Hanok is Korea's traditional housing, which is build detached unit. Most of the People who live in the environment of residential high-rise apartments likes new residential environment, and pursue eco-friendly homes, health homes, especially traditional Hanok was reassure potential. In urban context, resident think more compact land use in Hanok also, because Hanok is dissatified in compact land use, and it should be build as more economic aspect. The purpose of this study is to propose a typology which traditional Hanok also can be build higher land use and traditional values as a modern housing type; First of all, clustered Hanok is formed by traditional houses and interior spaces in modern house., and its types are configured by lifestyle of modern and image element of traditional Hanok. This kinds of clustering Hanok can be seen from historical city, but the trends is a minority of the housing type and form. Now, the modern clustering Hanok, even though handful of cases, appears as sustainable housing type, its possibilities as a new housing should be more detailed researches. A elements of Modern cluster Hanok discused in layout, plan, envelopment of house, structure, roofs, and the coordination of the element can be so much diverse.

• KIEAE Journal
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• v.8 no.4
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• pp.3-9
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• 2008

The rapid urbanization after 1970s caused the shortage of dwellings in urban areas. As the result, the underground dwellings were developed to compensate for the insufficient dwelling spaces. While the underground dwellings have some advantage in the respect of thermal and acoustic environment, they usually have the basic problems in the indoor air quality because of the lack of natural ventilation through small window areas. The purpose of this study is to investigate and to improve the indoor air quality of underground dwellings. Thirty Units in Seoul and Gyung-Gi Province were investigated into the indoor environmental conditions. For the purpose of the improvement of their indoor air quality, Automatically-operated ventilating fan was installed in a sample unit which has worst indoor environmental condition. Then the indoor air quality was monitored when it was operated by $CO_2$ control system and timer. Finally economic feasibility study was made considering the effect of the improvement of indoor air quality. The extra cost for installing timer could be paid back only in 10 months, so timer-installed automatic fan is recommended to improve the indoor air quality of underground dwellings.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.18 no.1
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• pp.137-147
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• 1988

This study was designed to investigate the effects of irradiation on the salivary ductal cells, especially on the intercalated ductal cells of the rat parotid glands. For this study, 36 Sprague-Dawley strain rats were irradiated on the head and neck region with absorbed dose of 15Gy by Co-60 teletherapy unit, Picker's model 4M60. The conditions irradiated were that field size, SSD, dose rate and depth were 12×5㎝m, 50㎝, 222 Gy/min. and 1㎝. respectively. The experimental animals were sacrificed 1, 2, 3, 6, 12 hours and 1, 3, 7 days after the irradiation and the changes of the irradiated intercalated duct cells of the parotid glands were examined under the light and electron microscope. The results were as follows: 1. Under the light and electron microscope, the nucleus, mitochondria and secretory granules showed severe changes in the early stage after irradiation and the most severe cellular de- generations were observed 2 hours after irradiation, but the repair processes began from 6 hours after irradiation. 2. Under the electron microscope, loss of the nuclear membranes, derrangement of the chromosomes, swelling and destruction of the secretory granules, and widening of the intercellular spaces were observed after irradiation. 3. Under the light microscope, atrophy and irregular proliferation of the ductal cells, cuboidal metaplasia, hyperchromatism, and the construction or obstruction of the lumen were observed after irradiation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.169-175
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• 2011

This paper addresses mobile IP router which communicate between nodes in Ad Hoc network as well as supply attachment to outer Internet. Ad Hoc network is one which exchanges information through cooperations among nodes without wire infrastructure, mobile IP router considers the network as one mobile unit, and supports Internet connection in mobile as well as fixed spaces. Therefore, this router can accommodate the routing of Ad Hoc network, and provide nodes in Ad Hoc network with Internet connection. So mobile IP router can provide Ad-Hoc terminals with the diverse wireless services, such as Internet connection service, routing, mobility, and so on.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.316-324
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• 2004

Sinorhizobium sp. strain MUS10 forms nitrogen-fixing stem nodules on Sesbania rostrata, a tropical green manure crop. In this study, the ultrastructural events associated with the formation of stem nodules were investigated. Sinorhizobium sp. strain MUS10 entered the host tissue through cracks created by the emerging adventitious root primordia and multiplied within the intercellular spaces. During early phases of infection, host cells adjacent to invading bacteria revealed cellular damage that is typical of hypersensitive reactions, while the cells at the inner cortex exhibited meristematic activity. Infection threads were numerous in S-day-old nodules and often were associated with the host cell wall. In several cases, more than one infection thread was found in individual cells. The junction at which the host cell walls converged was often enlarged due to fusion of intracellular branches of infection threads resulting in large infection pockets. The infection threads were made up of a homogeneous, amorphous matrix that enclosed the bacteria. Several finger-like projections were seen radiating from these enlarged infection threads and were delineated from the host cytoplasm by the plasma membrane. As in Azorhizobium caulinodans induced root nodules, the release of Sinorhizobia from the infection threads into the plant cells appears to be mediated by 'infection droplets'. A 15-day­old Sesbania stem nodule revealed typical ultrastructure features of a determinate nodule, containing several bacterioids within symbiosomes.

• Korean Journal of Environmental Agriculture
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• v.37 no.1
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• pp.1-8
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• 2018

BACKGROUND: Different physical and chemical properties of biochar, which is made out of a variety of biomass materials, can impact water movement through amended soil. The objective of this research was to develop a decision support tool evaluating the impact of the shape and the size distribution of biochar on soil saturated hydraulic conductivity ($K_{sat}$). METHODS AND RESULTS: Plastic beads of different size and morphology were compared with biochar to assess impacts on soil $K_{sat}$. Bead and biochar were added at the rate of 5% (v/w) to coarse sand. The particle size of bead and biochar had an effect on the $K_{sat}$, with larger and smaller particle sizes than the original sand grain (0.5 mm) decreasing the $K_{sat}$ value. The equivalent size bead or biochar to the sand grains had no impact on $K_{sat}$. The amendment shape also influenced soil hydraulic properties, but only when the particle size was between 3-6 mm. Intra-particle porosity had no significant influence on the $K_{sat}$ due to its small pore size and increased tortuosity compared to the inter-particle spaces (macro-porosity). CONCLUSION: The results supported the conclusion that both particle size and shape of the amended biochar impacted the $K_{sat}$ value.

• Journal of Environmental Science International
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• v.25 no.12
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• pp.1701-1715
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• 2016

This study is a basic investigation of the contents and services relevant to the domestic vacation house business. In which, the trade scale, types of housing, and environmental conditions of various property locations were analyzed. The characteristics of properties listed on the Japanese website that conducts the greatest volume of vacation house trade in Japan were examined, and the following results were obtained: Villa areas, villas, and resort condos (resort mansions) are the three basic types of properties handled in the vacation house trade. In this market, sales per unit in villa areas and per spaces in resort condos accounted for the highest volume of trade, followed by that of villas (individual houses). In terms of land area, floor area, and sales price per house type, the relatively cheaper small and medium-sized vacation houses are more frequently traded, than expensive large-scale villas. In particular, small multi-family type villas (such as in resort condos) are the most popular. Land and floor area, and sales prices all show considerable variation depending on the type of property considered. Therefore, a business initiative to provide a more detailed classification of properties is required. In terms of the environment of vacation properties, most are located on coasts, plateaus, or inland mountains, and are generally within three-hours' traveling distance of large cities.

• Journal of the Korean housing association
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• v.26 no.5
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• pp.45-52
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• 2015

Following natural disasters, there is a need to develop temporary housing through the rapid installation of mass-produced prefabricated housing. This study has developed a model construction manual for prefabricated temporary housing installable in underground spaces. First, the temporary housing prototype was drawn based on opinion poll results from earlier studies. $4.32m^2$ was calculated as the basic unit of the temporary housing living space for one person. Units included panel type, box type and mixed-type, for a variety of field conditions and scales. In order to enable space expansion and movement desirable to the user, the prototype was combination of panel and box types. The drawn prototype was utilized as the basic design template for producing prototypes and for the manual. Second, the possibility of utilizing subway stations as temporary housing was verified through the production of the prototype, and the construction process was summarized in the manual. The manual was developed in the form of a checklist to provide a guideline for users to build with prefab materials.

• Korean Journal of Human Ecology
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• v.10 no.3
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• pp.303-315
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• 2001

The purpose of this study is to evaluate the housing unit and investigate needs of housing in Home Economics curriculum of Home Economics teachers. The questionnaire survey was conducted 98 teachers participated in the minor training course in Chungbuk, August of 2000. When the teachers made their class in the section of housing, they emphasized respectively as the textual order: the space of housing and family life, the utilization of space, clean of residing circumstance in the middle school: and in the high school there was also concerned to the textual order: choice of housing, the house planning, interior design, maintenance of house. The teachers focused into the arrange of furniture and interior design for the students in the class, drawing of a plan in the contents of practical experience and performance. According to the survey results, the main point of class in housing should be emphasized the arranging of own room and function of other spaces in house for the students in the middle school. The high school curriculum should focus on the practical area to connect with the interior design. And in the section of housing it was needed to add the contents of management in the multi-family housing, housing problems, neighborhood environment for elderly, and also community planning.