• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.71-72
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• 2022

In this paper, the performance evaluation of the vibration damping ratio according to the polymer mixing ratio of the polymer modified mortar used as the floor finishing material of the apartment building structure was evaluated. To compare the vibration damping rate, ordinary potland cement (OPC) mortar and polymer modified mortar (PMM) were prepared. In addition, the mixed polymer was mixed with Styrene Butadiene Rubber (SBR) liquid polymer with a solid content of about 49%. Accordingly, the W/C of the test specimen was adjusted and compounded, and the experiment was conducted by mixing 5 types of the test specimen: OPC-60, PMM-5%, PMM-10%, PMM-15%, and PMM-20%. In addition, in order to adjust the W/C of the specimen, the fluidity of each specimen was set as 210 (±5) mm. The specimens measured density and flow in fresh mortar and after curing for 28 days, flexural strength, compressive strength and ultrasonic pulse were measured. The attenuation rate was shown. The experimental results showed that the density increased according to the mixing of the polymer, the flexural strength increased as the mixing rate of the polymer increased, and the compressive strength was decreased. In addition, it was shown that the vibration damping rate increases with the increase in the amount of polymer incorporated.

• Journal of the Korean Society of Floral Art and Design
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• no.41
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• pp.25-44
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• 2019

The purpose of this study is to identify the differences between consumers and suppliers about the necessity and effectiveness of hand-tied bouquet packaging in a retail shop and consumer needs of floristry packaging for sustainable condition were surveyed and analyzed using questionnaire format. In the introduction, the understanding and sustainability of floristry design were considered. The questionnaire consisted of general purchasing type, packaging related items, and consumer and supplier profile. Consumers were middle class residents living on Mokdong apartment complex, a small number of consumers who aren't living on Mokdong and workers and suppliers were florists currently active nationwide. This study suggests an effective and strategic packaging direction that reflects consumer needs, focusing on the similarity and difference of their needs and it presents them as business models. The results of the future research are expected to be the basis for producing and distributing packaging design.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.222-228
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• 2024

This study aims to anal yze the social benefits of introducing a sel ective demol ition system for buil dings. Incremental revenue, incremental cost, and incremental profit for the entire nation were derived based on the calculated costs and revenues of selective demolition for a 2,400 m² apartment complex. In conducting selective demolition on a 2,400 m² building, the increase in demolition construction costs, the reduction in waste disposal costs due to the decrease in mixed waste, and the revenue obtained from recycling separated and sorted waste were comprehensively reviewed. It was calculated and analyzed that, compared to general demolition work, a total cost-saving effect of 34,727,000 KRW could be expected. Extrapolating this to the entire nation, based on the year 2020, which had the highest construction waste generation, it is estimated that the social benefits would amount to 746,782,886,000 KRW.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.19 no.4
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• pp.1-7
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• 2023

In Korea, it is also mandatory for most buildings to receive energy efficiency rating certification from 2020 for the purpose of reducing greenhouse gas emissions and expanding green buildings. However, the issue of the accuracy of the ECO2 program continues to be raised, and comparisons have been made with dynamic energy analysis programs in a single type of building according to a single area. However, comparisons between multiple building types and multiple areas are insufficient. Therefore, in this study, cooling and heating loads according to multiple building types and multiple areas were analyzed through ECO2 and TRNSYS programs. The regions were supposed to be Seoul, Daejeon, Gwangju, and Busan and the building types were supposed to be office buildings and apartment houses. The annual average building load values from ECO2 were higher than those from TRNSYS. Among residential buildings across the four regions, the largest discrepancy was 41.4% in Seoul. Conversely, for commercial buildings, the most significant difference in annual average loads was noted in Gwangju, at 37.9%.

• Journal of Society of Preventive Korean Medicine
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• v.18 no.2
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• pp.11-30
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• 2014

Objective : To compare the differences in health behaviors by chronic diseases of middle-aged living in Seoul's low-income housing Method : Of the 1469 residents aged 35 to 60 living in low-income housing in Seoul's District A, 318 were equal probability of selection method selected. t-test, ANOVA, $x^2$, OR(95% CI, P-value) were selected to analyze the data, and the confidence interval was 5%. Results : There were no significant differences in all health behaviors by vascular and metabolic, But there was a statistically significant difference for gastrointestinal diseases caused by sleep hours(p=0.001), liver diseases caused by smoking, drinking and sleep hours(p=0.004, p=0.001, and p=0.033, respectively), musculoskeletal diseases caused by sleep hours and health exam(p=0.0000 and p=0.002, respectively). Also, statistically significant differences were found for tumors caused by sleep hours(p=0.004), depression by the sleep hours and health exam(p=0.001 and p=0.013, respectively), allergies by in sleep hours(p=0.004), thyroid diseases by smoking and health exam(p=0.013 and p=0.007, respectively). After adjusting for the confounding factors for diseases, OR was obtained for each health behavior. There were no statistically significant differences in all health behaviors for vascular, metabolic, and tumors. However, the OR for gastrointestinal diseases 4.10(1.63-10.36, 0.0028) and 2.96(1.05-8.41, 0.0041) at 5-7 and 7-9 sleep hours. The OR for liver diseases was 3.13(1.03-9.48, 0.0437) at 7-9 sleep hours, the OR values for musculoskeletal diseases were 2.91(1.23-6.88, 0.00149), and 4.46(1.68-11.86, 0.0027) at 5-7 and 7-9 sleep hours. OR for depression were 4.82(1.70-13.66, 0.0031) and 4.13(1.19-14.31, 0.0026) at 5-7 and 7-9 sleep hours. OR for allergy were 2.78(1.22-6.32, 0.0015) and 3.93(1.49-10.39, 0.0058) at 5-7 and 7-9 sleep hours. There were statistical significances for liver diseases for 1-2 times of health exam at 0.35(0.14-0.90, 0.00301), for liver diseases for 1-2 times of health exam at 0.35(0.14-0.90, 0.00301), for musculoskeletal diseases for 3-4 times of health exam at 0.26(0.09-0.79, 0.0175), for depression for 3-4 times of health exam at 0.17(0.04-0.66, 0.0106), for allergies for 1-2 times of health exam at 0.30(0.13-0.70, 0.0055), and for thyroid diseases for 1-2 times and annually of health exam at 0.07(0.01-0.60, 0.00154), 0.09(0.01-0.96, 0.0461). We known significant difference the health behaviors by the diseases. especially in sleep hours and health exam times Conclusion : Only sleep hours and health exam caused statistically significant differences in chronic diseases. but the sleep hours was postitively correlated with the risk of disease, while health exam were inversely related.

• Journal of the Korean Geographical Society
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• v.31 no.3
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• pp.577-592
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• 1996

The forming process of poverty region in Taegu and the feature of its spatial distribution which are reviewed hitherto can be summarized like this. 1) In the froming porcess of poverty region in Taegu, during the soverignty of Japanese Empire petty farmers became tenantry by the colonial agricultural policy of Japanes Empire and some of those came into the city and g\became urban poor class. They generally lived in poor houses or dugouts in the city, and 6.6$\circ$ of poor house and dugouts of the whole country were in Taegu and 4.9$\circ of the popolatio in Taegu resided there. During the period of disorder, because of the historic accidents, such as the restoration of independence and Korean War, the returnees from aboad and refugees converged into the big city so that those who need the country's relief stood out as new poor class. They generally made their dwellings with tents and straw-bags on vacant grounds in suburbs living form hand to mouth and shaped the poor houses area, so-clalled "Liberated Village". During the developing period, the number of those who need aid gradually decreased, but the problem of poor people by the city-concentration of the poeple who shifted from agricultrual jobs by economic development came to the front. They mostly lived in squatter area forming large poor class area, and generally located near the center of Taegu consisiting of West. South. East Ward. 2) Reviewing the the feature of spatial distribution, the proportion of poor class are highest within 1~2km from the center of the city and also high within 2~3km form the center and suburbs. The poor class area in the center of the city are mostly cleared and removed area and in suburbs by the construction of permanently leased, and leased apartments large grouped poor class areas are forming. In Taegu, 16 low-income class group residence areas and residential environement improving areas are dispersed so that they came under the so-called poor class area. But by the improvement of dewelling environment and living the poor people who lived in groups dispersed or bettered their living for themselves, so the poverty area is greatly chaning into average-levelled residence area, and on the other hand, large poor people's apartment complexes are being constructed in suburbs. 3) Up to now, the distribution of poverty area could be limited its scale to generally the area within 1~3km because the poverty region which had been in suburbs relatively came near the center of the city by the rapid urbanization and poor people preferred that area because of the living convenience facilities as well as the transportation facilities and job-hunting being near the center of the city. But now poor people's apartment complex is being constructed regardless of their zone of job sites, so the low proportion of occupation is pointed as a new problem.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Korean small business review
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• v.43 no.2
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• pp.59-86
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• 2021

The platform concept has been used for business operations in various forms: product platforms, transaction platforms and industry platforms. All these platforms have common characteristics of having 'core' that is reused frequently and 'peripherals' that are less reusable and changed often. Companies use platforms to enable efficient development and creation of product family, transactions and innovation. These platforms provide new opportunities for many small and medium-sized companies (SMEs) by bringing changes to traditional industrial structures focused on the products rather than platforms. The service robotics industry in South Korea is mainly composed of technology-intensive SMEs due to its small market size. Although these SMEs succeed in developing technologies, they have difficulties creating and expanding markets to sell products. Thus, this study addresses the characteristics and problems of the South Korean service robotics industry and analyses how ROBOPRINT, one of the SMEs in the service robotics industry, successfully creates and continuously expands the service robot market by adopting platform concept. The results indicate that ROBOPRINT has been applying two types of platforms: product and transaction platforms. First, ROBOPRINT created art robots that were apartment mural service robots. Rather than selling art robots, the company developed various robots such as painting robots, building exterior wall-cleaning robots by reusing the core technology of the robots. The company also developed various robots according to the buyers request. In addition, the company used the robots to directly provide apartment mural services for customers. This mural service has been extended into various areas, not only in apartments but also in soundproof walls, underground passages, and retaining walls. Besides, ROBOPRINT added new services continuously by developing technologies such as virtual reality. Second, ROBOPRINT mediated mural service buyers and mural designers. This platform reduced buyers' workload, which necessitates requesting mural services to ROBOPRINT and searching for mural designers. For designers, this opened up new opportunities to participate in the mural business. The platform attracted both mural buyers and designers who were scattered before. Finally, ROBOPRINT seeks to expand the platform's scope to outside company. To share internally reused ROBOPRINT's technology with other companies, the company participated in Daegu city's 'New Technology Platform Industry'. Furthermore, ROBOPRINT is trying to share the service platform by leasing robots to other companies. This allows external agents to develop technologies and provide services by reusing resources from ROBOPRINT. This study contributes to existing theories by showing that SMEs continuously create and expand markets by building various platforms. Moreover, it provides useful implications for practitioners by describing the firm's specific platform-building strategy.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.57-67
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• 1997

The objective of present paper is to investigate elasto-plastic behaviour and estimate the resistance capacity of a beam-shear wall structural system against earthquake ground accleration exciations. Pushover analysis is adopted to estimate inttiate and post stiffnesses and yielding point for inelastic response analysis in LPM (Lumped Parameter Mass) model, and modified Clough model is used as the hysteresis rule of each story. Three earthquake waves are used in the analysis but their peak ground accelerations are changed to be 0.12g, 0.24g. It is assumed that the earthquakes act in the longigtudianl direction of a 25 Story apartment building which consists of two some unit plan. The distribution of story ratio and ductility ratio are estimated and discussed within Korean, Japanese code and UBC.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.190-198
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• 2008

Recently construction equipments have been used in line with building the structures that have become taller, larger and complex. And as the works at the elevated level for apartment and residential-commercial building projects have been on the rise, the number of tower cranes mobilized tends to be increased too. Due to such an increase in using the equipment serves the critical factor for the project management. The climbing-type tower crane, which increases its height following the structure, has been increased and the need for selecting the optimal model has been increasingly Important in securing the stability. The study hereby proposes the model to evaluate the stability of the climbing-type tower crane. The model was designed to assist in selecting the type of crane as well as in developing the design of Collar comprising the 3 types of support member, evaluating the stability and designing the embed. The model proposed is expected to make commitment in selecting the optimal type of equipment and evaluating the support member and embed for enhancing the stability, thereby ultimately enabling to implement the prefect in efficient way.