• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.724-726
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• 1996

In this paper, we propose an optimal daily operation model for the total energy system which includes cogeneration, thermal storage and electrical charger and ice storage facilities. Storing and utilizing the surplus thermal and electrical energy, the daily operation cost could be reduced and more efficient use of thermal energy could be achieved. The ice storage cooling system has a merit of reduce the electricity cost by time of day rate(peak/off-peak). And also, refrigerator can be down sized compare to the other cooling system From this model, operation costs of the sample cogeneration system with/without auxiliary facilities are obtained and compared to each other. In case study, the sensitivity of operating cost is simulated according to the variation of cogeneration production cost, electricity rate, etc.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.12 no.4
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• pp.240-251
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• 1983

The municipal government of Daejeon, Korea set up a plan to retrofit solar energy to the existing swimming pool. The pool was constructed in 1980, and meets the requirements of International standard. It will be used for the 1986 Asian Games and the 1988 Seoul Olymipics. The roof structure of the existing pool is to be modified to accomodate trickle solar collectors. In addition, various energy conserving ideas will be applied to the existing building structure. For the prevention of over heating of collectors on the roof, natural air convection scheme will be adopted within the collector system. Natural convection of passive type heating would be also adopted for the space heating of the pool when the system is idle. At present, the pool can be utilized only for two months a year without auxilairy heating. With oil heating, the energy cost would be too high for the normal operation. When this project completed in March 1984, it would be expected to be openable for seven months a year without a significan amount of auxiliary heating. In this project, two dimensional numerical analysis technic have been used to analyse the characterisitics of thermal performance of the swimming pool system. An experimental tat verification of the theoretical analysis have been also attempted.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.282-287
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• 2017

The purpose of this study was predicted the effects of mixing and diffusion due to the operation of the apparatus before the development of the mixed diffusion device for the decontamination absorbent to minimize the influence of contaminant inflow due to radiation accident. The tracer used for the flow characteristics was $^{68}Ga$, $^{99m}Tc$, which is a radioactive isotope, and 2 inch NaI radiation detector was used to detect it. The impeller of the decontamination mixed diffusion system applied to this study was made into three types and the mixing diffusion effect was compared. As a result of analyzing the flow characteristics of the radio-isotope with decontamination mixed diffusion device, mixing, diffusion and flow pattern were obtained. The radial mixing type impeller was able to diffuse to the water surface by the upflow flow, and the fin structure was adjusted for finding optimal conditions. The model 3 type consists of a fin guiding part and an auxiliary fin so that the diffusion speed is higher than that of other types of impellers. It also showed a short time to reach complete mixing.

• Journal of the Korean Regional Science Association
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• v.34 no.3
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• pp.29-42
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• 2018

Population growth in Korea is slowing down, and the ratio of 1~2 person households has exceeded 53.3% of the total. And in the future, it is becoming more important how to accommodate as proper planning in residential areas. In this paper, we examine whether the existing district unit plans respond appropriately to the trend of the increase in small-sized housing, and we propose improvement plans for elements of the district unit plan and measures to enhance its applicability in response to small-sized housing. To do this, we analyzed the guidelines and contents of the district unit plans related to small-sized housing in recent 6 residential sites, and derived problems and improvements through literature review and expert consultation. As a result of the study, we proposed the items that need to be reflected in the district unit plan related to various housing type for one person household. And planning elements related to households, housing site, building layout, and architectural shape and appearance were also proposed, which were suitable for single-person households, such as small-sized communal housing, share-house, and single-person housing. It also suggested that single-person households should be considered for housing characteristics, including introduction of auxiliary welfare facilities such as unmanned delivery box and guest houses, and exclusion of low-demand auxiliary welfare facilities such as kindergartens. The suggested content can be used to make guidelines for small-sized housing in district unit plan.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.3068-3084
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• 2021

Investigations of large commercial aircraft impact effect on nuclear power plant (NPP) buildings have been drawing extensive attentions, particularly after the 9/11 event, and this paper aims to experimentally assess the damage and vibrations of NPP buildings subjected to aircraft crash. In present Part I, two shots of reduce-scaled model test of aircraft impacting on NPP building were carried out. Firstly, the 1:15 aircraft model (weighs 135 kg) and RC NPP model (weighs about 70 t) are designed and prepared. Then, based on the large rocket sled loading test platform, the aircraft models were accelerated to impact perpendicularly on the two sides of NPP model, i.e., containment and auxiliary buildings, with a velocity of about 170 m/s. The strain-time histories of rebars within the impact area and acceleration-time histories of each floor of NPP model are derived from the pre-arranged twenty-one strain gauges and twenty tri-axial accelerometers, and the whole impact processes were recorded by three high-speed cameras. The local penetration and perforation failure modes occurred respectively in the collision scenarios of containment and auxiliary buildings, and some suggestions for the NPP design are given. The maximum acceleration in the 1:15 scaled tests is 1785.73 g, and thus the corresponding maximum resultant acceleration in a prototype impact might be about 119 g, which poses a potential threat to the nuclear equipment. Furthermore, it was found that the nonlinear decrease of vibrations along the height was well reflected by the variations of both the maximum resultant vibrations and Cumulative Absolute Velocity (CAV). The present experimental work on the damage and dynamic responses of NPP structure under aircraft impact is firstly presented, which could provide a benchmark basis for further safety assessments of prototype NPP structure as well as inner systems and components against aircraft crash.

• Journal of architectural history
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• v.22 no.2
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• pp.43-54
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• 2013

Compared to Early Chosun Dynasty, the spatial structure of most local Eupseongs of Korea had a standardized change with the expansion and spread of the Rye-hak(禮學:a study of confucius Rite). Meanwhile in the process of rebuilding Eupseongs there was a tendency of relocation of the local government offices(官衙) and its attached facilities in terms of functions and use. Although it was PyeongSanseong Miryang Eupseong had an unreasonable spatial structure locating Gaeksa(客舍; accommodation house for visitors) in the middle of the local government office complex, and Dongheon(東軒;main office building) in the east of it before the Japanese Invasion of Korea in 1592. However with the reorganization of spatial Structure of local Eupseongs after the Japanese invasion Gaeksa was moved to the foot of Adongsan where commanded a fine view of river. Dongheon was moved to the center of Eupseong for the effective management of its auxiliary organizations. It was because road system and administrative efficiency had a serious effect on deciding the location of the local government office and its attached facilities. After the Japanese invasion Hyangchoeng(鄕廳), having been out of Eupseong, also was moved to the independent location within Eupseong separate from Dongheon and Gaeksa. It seemed to take into account the autonomy of Hyangchoeng. Dongheon, Gaeksa, and Hyangchoeng which are the crucial facilities of Milyang Eupseong were arranged at each angular point of big triangle. In order to enhance the administative efficiency, the attached administrative facilities were arranged surrounding Dongheon and Hyangchoeng. The spatial structure of Milyang Eupseong in the late Choseon dynasty was of great difference from that of uniformly organized system of early Choseon Period. It was because the development of administrative function, the pursuit of efficiency, and commercial progress had a great impact on the change of urban space.

• Journal of the Korean Solar Energy Society
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• v.36 no.5
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• pp.73-89
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• 2016

To assure maximum economic benefits and the energy performance of solar water heating systems, the proper sizing of components and operating conditions need to be optimized. In recent years, a number of studies to design optimally solar water heating systems have been tried. This paper presents a design method for optimizing the various capacity-related and installation-related design variables based on life cycle cost using a genetic algorithm. The design variables considered in this study included the types and numbers of solar collector and auxiliary heaters; the types of storage tanks and heat exchangers; the solar collector slope; mass flow rates of the fluid on the hot and cold sides. The suggested method was applied for optimizing a solar water heating system for an elementary school in Seoul, South Korea. In addition, the effectiveness of the proposed optimization method was assessed by analyzing the obtained optimal solutions of six case studies, each of which was simulated with different solar fractions. It is observed that a trade-off between the equipment cost and the energy cost results in an optimal design that yields the lowest life cycle cost. Therefore, it could be helpful to apply the optimal solar water heating system by comparing the various design solutions obtained by using the optimization method instead of the engineer's experience and intuition.

• Korean Institute of Interior Design Journal
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• v.22 no.5
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• pp.33-41
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• 2013

It is not surprising that senior centers are widely used nationwide as Korea becomes an aging society. This study attempts to figure out senior citizens' needs and evaluations of senior centers in terms of characteristics of their usage and spatial composition. A face to face interview using a questionnaire was conducted on 255 senior citizens who has been using senior centers located in Jangyu new city apartment housing complex. The questionnaire is composed of questions asking characteristics of their usage, evaluations of spatial composition, and respondents' demographic data. Findings are: First, it is found that many respondents visit senior centers everyday and spend 4 to 6 hours a day. Their main activities are meeting friends, taking hobbies, and dining. That is, senior centers play a pivotal role in daily lives of senior citizens. Such characteristics should be taken into account in space design when planning to build a future senior center; Second, it is found that senior centers play a role of auxiliary space for building their sense of belonging and familarity. It is found that furnitures in senior centers are worn out and safety measures are not sufficiently considered; Third, it is found that they highly evaluate flexible spacial composition that could be partitioned or extended depending on occasions even though they prefer independent space; Fourth, it is found that kitchen facilities are not large enough considering the fact that more that half of the respondents have their lunches in senior centers. Even though they do not cook for themselves kitchen space should be large enough for preparing meals simultaneously for a large number people.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.1 s.11
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• pp.75-90
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• 1998

In this study, as a method for management of waterquality in stream, we build a database on a environmental information such as a pollution source, a waterquality. And especially, we simulate the BOD concentration which is a index indicate the status of organic pollution in stream. Also This study purposes not only building a database on all sorts of envirnomental data, but also searching, statistic and analysis of the database. The result of this study enables us to see and understand contamination state in stream esaily, so it can help to enhance the attention. Also, we can quickly know study area and the degree of effects when water contamination occurs abruptly. And also, we can compare and know pollution source state and the pollutant load among districts. It is expected to use it as an auxiliary basis when we make a policy about pollutant load reduction, because we can know the extent of the pollution in strean by each a pollution source.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.2
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• pp.49-58
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• 2003

The linear motor has not only no backlash and less friction, resulting in very high accuracy, but also mechanical simplicity, higher reliability, and longer lifetime. In this study, a large-capacity hybrid mass damper using linear motor principle has been developed to suppress vibration of large structures. It is designated linear motor damper in this paper. The LMD has been designed to be able to move the auxiliary damper mass of 155kg up to $\pm$250mm stroke. A series of performance tests for LMD control system with $H_{winfty}$ robust controller have been carried out on the full-scale steel frame structure. Through the performance tests, it is confirmed that vibration response levels are reduced down 10dB for the first and second modes of the test structure.