• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.123-130
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• 2010

In this study, mixed recycled coarse aggregate (RCA) was produced by mixing RCA from waste concrete in order to evaluate a new method of RCA production. Bond strength between reinforcing bars and RCA concrete was qualitatively evaluated as a part of continuous studies to establish design code of reinforced concrete structural members using recycled aggregate. For practical application, specimens were manufactured with the ready mix RCA concrete. Parameters investigated include: concrete compressive strength (i.e 21, 27 and 40 MPa), replacement levels (i.e 0, 30, 60 and 100%), bar position (i.e vertical and horizontal) and bar location (75 and 225 mm). For the pull-out test, each specimen was in the form of a cube, with each side of 150 mm in length and a deformed bar, 16 mm in diameter, was embedded in the center of each specimen. From the test results, the most of HT type specimen with compressive strength of 21 and 27 MPa showed lower bond strength than the ones provided in CEB-FIP and considered in reinforcement location factor ($\alpha\;=\;1.3$). It was reasoned that bonded area of top bar specimen was reduced at the soffit of reinforcement because of bleed water of fresh concrete. Therefore the reinforcement location factor in current KCI design code should be reviewed and modified.

• Journal of the Korea Society of Computer and Information
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• v.28 no.1
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• pp.49-54
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• 2023

The Global Positioning System (GPS) was developed for military purposes and developed as it is today by opening civilian signals (GPS L1 frequency C/A signals). The current satellite orbits the earth about twice a day to measure the position, and receives more than 3 satellite signals (initially, 4 to calculate even the time error). The three-dimensional position of the ground receiver is determined using the data from the radio wave departure time to the radio wave Time of Arrival(TOA) of the received satellite signal through trilateration. In the case of navigation using GPS in recent years, a location error of 5 to 10 m usually occurs, and quite a lot of areas, such as apartments, indoors, tunnels, factory areas, and mountainous areas, exist as blind spots or neutralized areas outside the error range of GPS. Therefore, in order to acquire one's own location information in an area where GPS satellite signal reception is impossible, another method should be proposed. In this study, IMU(Inertial Measurement Unit) combined with an acceleration and gyro sensor and a geomagnetic sensor were used to design a system to enable location recognition even in terrain where GPS signal reception is impossible. A method to track the current position by calculating the instantaneous velocity value using a 9-DOF IMU and a geomagnetic sensor was studied, and its feasibility was verified through production and experimentation.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.5
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• pp.139-150
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• 2007

As computer technology has been rapidly advanced, geographic information system (GIS) is recently used in many disciplines. In this study, for a model area in Seoul, seismic hazard potential relating to site effects, which are influenced by the subsurface geotechnical conditions, was estimated using the GIS tool. The distribution of pre-existing borehole drilling data in Seoul metropolitan area was examined for the regional estimation of site-specific seismic responses at the model area. Spatial geo-layers across the entire model area were predicted by constructing a GIS-based geotechnical information system (GTIS). A microzonation of site period $(T_G)$ for estimating site-specific seismic responses at the model area was performed within the GTIS. The spatial microzoning map of $T_G$ indicated seismic vulnerability of two- to four-storied buildings in the model area. Furthermore, a site classification map for determining the design ground motion was established based on the $T_G$ within the GTIS. This informed that most of location in the model area was categorized into current site classes C and D. This seismic microzonation framework for the model area could be applicable particularly in the entire Seoul metropolitan area based on the pre-existing borehole data.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.1-6
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• 2016

As manufacturing industries become globalized, product design affects every area of organization. The design sets the goals for a number of different departments, so if it fails to effectively communicate these goals, the entire organization is less efficient. In addition, To communicate clearly, the design must represent a product that meets its technical specification. GD&T (Geometric Dimensioning and Tolerancing) is one of the most important factors, which has an effect on efficiency of manufacture system, in designing products. However, most of designers in different industries are prone to ignore the importance of GD&T. To analyse the importance of GD&T compliance with international standards for design drawing, a comparison analysis of the difference between two methods, composite profile control and multiple single segment profile control, is performed on three different cases and suggests how it used to be more suitable. Composite profile tolerance is specified by a dual feature control frame that has one profile symbol specified with two lines of tolerance information. Whereas a multiple single segment profile control is when two or more single segment profile callouts are used to define the location and/or orientation and/or size and/or form of a part feature. In this study, the following results will be provided : a clear definition and an obvious difference of the tolerance zone, datums and datums sequence and minimization of tolerances. On this study, composite profile tolerance and multiple single segment profile tolerance were discussed. Next steps of research will consist on reaching more accurate results for profile control. Further research will be focused on dealing with the remaining 14 symbols of GD&T.

• Journal of the Korea Fashion and Costume Design Association
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• v.22 no.3
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• pp.155-167
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• 2020

Despite accelerating market changes in the beauty service industry, there are still inadequate service education programs and a lack of objective data and research to develop systematic policies to strengthen competitiveness, thereby fostering the beauty service industry. Accordingly, this study will examine the factors that affect customer satisfaction in terms of customer touchpoints, hence uncovering what the beauty service needs to develop systematic customer service education programs. It aims to contribute to the improvement of beauty service quality by providing basic empirical data that is necessary to build service education programs and strengthen the touchpoint staffs' job competency. A total of 16 people, 8 male, and 8 female customers in their 30s and 40s, who have ever used hair shop services in the metropolitan area, and 8 male and female hair designers and owners, were interviewed during a 9week period from October 31, 2017, through December 30, 2017. The data was analyzed as follows in order to measure service quality, SERVQUAL was revised and supplemented according to the purpose of this study, and a table for customer satisfaction factors was constructed. In addition, the results of the study were derived by classifying the relations among the customer satisfaction factors with respect to the interviews. The results show that the price of hardware, the location of the store, and hair designers' ability, which are the direct components of customer satisfaction, have a great influence on the customer satisfaction considered when selecting the beauty services (hair shops). In addition, it can be seen that human services including human-ware, which are accompanying services make up a high proportion considering customer satisfaction factors.

• Journal of the Korean housing association
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• v.20 no.3
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• pp.37-45
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• 2009

For the young period, privacy is a crucial factor in establishing one's own identities, values and relationships. The capacity of residential environment to protect individual's privacy takes considerable part in influencing psychological and physiological development of adolescents. This study analyzed adolescents residential values and the elements of spatial plans for the passage and outdoor in Apartment Design Competition of Suwon A district in 2008. One hundred and ten middle and high school students living in Metropolitan area were selected and questionnaire was conducted during February 7 to February 15 in 2009. The data was analyzed by SPSS 11.0 program using one-way ANOVA and crosstab. The study results were summarized as follows; First, the adolescents valued 'safety' the most, regardless of their age and gender and the safety of adolescents commuting should be considered. Second, protecting their own private territories was next important element among other elements. Privacy can be protected by using movable walls, changing the doorway, dividing parents' and adolescents independent territory. Third, in terms of convenience, choosing location of children's room and walking way should be considered. Forth, from the survey, demand for indoors leisure activity was highly valued and required for aesthetic point of view. Considering the sculptures and facilities must satisfy the aesthetics and practicality. Fifth, in terms of social needs, 61.6% of people answered positively to the community facilities for social relationship. Residential environment affects enormous part of adolescents emotional and academic development. Therefore, designing residential areas for adolescents friendly should reflect the demands for safety, territory, convenience, aesthetic and social life.

• Journal of the Korea Concrete Institute
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• v.28 no.1
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• pp.95-104
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• 2016

Flexural strength of concrete ground slab reinforced with steel fiber is evaluated using the equivalent flexural strength ratio of steel fiber reinforced concrete based on the yield line theory. Recently, the European standard specifies that the tensile performance of the steel fiber reinforced concrete be evaluated directly from the residual flexural strength after the cracking of concrete. Thus, in the study, an experiment was carried out to evaluate the conventional equivalent flexural strength ratio and the residual flexural strength of the steel fiber reinforced concrete. Then the design flexural strength was investigated according to the location of a point load, based on the ratio of the radius of contact area of the load to the radius of relative stiffness. Design flexural capacity obtained from ACI 360R-10 was smaller than that from TR 34 (2003 & 2013). In addition, TR 34 (2013), which evaluates the design flexural capacity based on the residual flexural strength, showed slightly smaller value than TR 34 (2003).

• Journal of the Korean Geotechnical Society
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• v.37 no.5
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• pp.33-46
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• 2021

After the Gyeongju earthquake, which was the largest in the history of measuring instruments in Korea in 2016, and after the Pohang earthquake, where the pillars of pallet structures were destroyed in 2017, the seismic design standards for all domestic facilities have been revised and supplemented. In particular, during the investigation of the Pohang Earthquake damage cases, liquefaction damage that occurs mainly in countries with strong earthquakes such as the United States, Japan, and New Zealand was found, so studies are being conducted in depth to improve seismic design standards. In this study, the liquefaction potential assessment in the recently revised seismic design standard for port and harbor was reviewed, and an applicability review was conducted focusing on the newly cited liquefaction potential index (LPI). At this time, by varying the thickness and location of the sandy soil where liquefaction can occur, the LPIs for various cases were calculated and compared. Also, 22 LPI values in the practical port area were compared and reviewed along with performance of the liquefaction assessment based on the site response analysis using the boring-hole data of the actual 22 port sites.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.197-203
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• 2022

The purpose of this study is to establish an S.I. (Space Identity) considering the spatial location and cultural specificity of Jecheon Jungang Market, the oldest and largest market in Jecheon with historical characteristics. To this end, we identify the flow of the cultural tourism market, investigate and analyze the current state of Jecheon Central Market, and present a direction based on storytelling for each space. The concept of space design was divided into space, time, people, and culture as coexistence, and merchants, products, and shopping malls share temporality and coexist in one space. Therefore, the facilities for each floor consisted of a gate, information board, lighting, rest area, design bench facility, information center, business compliance line, floor sign, and gate floor sign for each floor. Through this, it is necessary to establish a mid- to long-term development strategy by establishing a step-by-step promotion strategy to predict the economic effect of creating new demand and increasing sales in Jecheon Central Market.

• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.161-167
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• 2010

To realize the U-healthcare system, the mobile patient monitoring system is of the essence. In this monitoring system, a patient's real-time data on biometrics and location must be transferred to predeterminate destination server ceaselessly. As the number of mobile patients increases steadily or mobile patients are moving into some specific area, the load balancing solution to real-time data congestion problem is needed. In this paper, we propose a new mobile patient monitoring system with Torus topology where three layers are connected hierarchically and the intermediate layer takes charge of priority-based load balancing. For the formalized design and verification of proposed system, we describe the overall structure with connectivity among its components and implement major components in pseudo-code by adopting a system specification-based approach. This approach makes the design and verification of our mobile patient monitoring system more flexible and accurate.