• Journal of the Korean GEO-environmental Society
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• v.24 no.10
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• pp.51-58
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• 2023

The dynamic behavior of the group piles supporting the superstructure in an earthquake is influenced by different complex dynamic mechanisms by the inertia force of the superstructure and the kinematic force of the ground. In an earthquake, The dynamic p-y curve is used to analyze the dynamic behavior of the pile foundation in consideration of the interaction of the ground, pile foundation, and superstructure due to the inertia force and the kinematic force. Most of the research has been conducted in order to confirm the dynamic p-y curve of the pile foundation by applying to the pile foundation installed on the single layered ground consisting of sand and clay, but the research for the multiple layered ground is insufficient. In this study, 1g shaking table tests were conducted to analyze the effect of the strata ratio of the top and bottom ground of the two layered sandy ground which has different relative densities on the dynamic behavior of group piles supporting the superstructure. The result shows that the maximum acceleration in the ground, the pile cap, and the superstructure increases as the strata ratio increases, and the location of the maximum bending moment of the pile foundation is changed. In addition, it was confirmed that the slope of the dynamic p-y curve of the pile foundation increased and decreased according to the strata ratio.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.4
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• pp.641-656
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• 2022

This article investigates how Baedal Minjok(BaeMin) has grown to be a dominant mobility platform operator in food delivery sector in South Korea and what roles its brand and branding have played in the process, drawing on the idea of origination. For the purpose, BaeMin is considered as a typical platformized mobility service provider and origination is framed to be an appropriate analytical lens for the business sector. For the origination conception, unlike mainstream neoclassical theory and concepts, is able to deal fairly well with the issues of imperfect competition, imperfect information, and monopolistic brand rent, which are apparent in today's platformized mobility services. Drawing evidence from textual data, empirical analysis pays particular attention to discursive and symbolic dimensions of BaeMin's socio-spatial biography. It is found that national origination underpinning ethnicity comprises an important pillar of BaeMin's brand and branding. Another form of place-based origination is also observed to matter, especially in the varied relation between the mobility service brand's owner and consumers. However, this configuration of BaeMin's brand origination has yet to be fully stabilized, as it has faced with serious challenges including brand vandalism and anti-brand movement especially since its merger to German food delivery platform giant Delivery Hero in 2020. This origination crisis moment appears to be associated with a series of contractions intrinsic to so-called 'platform capitalism'.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.662-675
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• 2022

This study was intended to investigate and analyze the current status of the plant community structure in order to provide basic data for the systematic conservation and management of the Buxus sinica area appearing on the ridgeline connecting the Gyeokjabong(Mt.) and Keungiljae, on Bogildo Island. In consideration of location characteristics such as density, topography, and direction of B. sinica appearing in the shrub layers, a total of 26 sites were set as the survey area for representative vegetation communities or areas with changes in topography. According to DCA and TWINSPAN, it was classified into 6 communities, namely Carpinus turczaninovii-Deciduous broad-leaved, C. turczaninovii, C. turczaninovii-B. sinica, C. turczaninovii-Evergreen broad-leaved, Q. acuta, and D. trifidus-Q. acuta. The community dominated by C. turczaninovii maintains the status quo for the present moment, however, Q. acuta will dominate the surrounding area in the long term, so Q. acuta has high succesion potential. In the case of the Q. acuta and D. trifidus-Q. acuta communities, Q. acuta, known as the climax species of warm-temperate forests, will maintain dominant status. In a case of B. sinica, the community dominated by C. turczaninovii will remain in good status due to the topographical conditions, but the community dominated by Q. acuta growth difficulties are expected due to the high coverage. In the relationship between environmental factors and vegetation distribution, analysis showed that only soil pH affect vegetation distribution. Furthermore, the soil acidity (pH) was 3.78-5.30, the electrical conductivity was 0.186-0.543 dS/m, and the organic matter content was 2.25-2.89%.

• Journal of the Korean Geotechnical Society
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• v.24 no.7
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• pp.61-73
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• 2008

Piles of a bridge pier are connected with the column through the pile cap (footing). Behavior of the pile foundation can be different according to the connection method between piles and the pile cap. Connection methods between pile heads and the pile cap are divided into two groups : rigid connections and hinge connections. Domestic design code has been specified to use rigid connection method for the highway bridge. In the rigid connection method, maximum bending moment of a pile occurs at the pile head and this helps the pile to prevent the excessive displacement. Rigid methods are also good to improve the seismic performance. However, some specifications prescribe that conservative results through investigations of both the fixed-head condition and the free-head condition should be reflected in the design. This statement may induce an over-estimated design for the bridge which has high-quality structures with casing covered drilled shafts and the PC-house contained pile cap. Because the assumption of free-head conditions (hinge connections) is unreal for the elevated pile cap system with multiple piles of the long span sea-crossing bridges. On the other hand, elastic displacement method to evaluate the pile reactions under the pile cap is not suitable for this type of bridges due to impractical assumptions. So, full modeling techniques which analyze the superstructure and the substructure simultaneously should be performed. Loads and stress state of the large diameter drilled shaft and the pile cap for Incheon Bridge which will be the longest bridge of Korea were investigated through the full modeling for rigid connection conditions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.3
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• pp.12-20
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• 2023

This study presents basic data on how to secure stability by analyzing the change in tensile force of steel rod and the inclination characteristics of PSC BOX in the "Temporary fixation system using internal prestressing tendon", which is mainly applied to construction of superstructures by FCM. To date, it has been difficult to confirm the changes in tension force of the steel rod and the inclination of the PSC BOX because the steel rod was installed vertically inside the pier and the PSC BOX. Therefore, measurement of the change in length of the steel rod and the displacement of PSC BOX were performed using a micro-measured FBG sensor. Comparisons of the calculated tensile force and the residual tensile force of the steel rod revealed that the safety factor decreased in all bridges. The cause was mainly identified to be the loss of tensile force in fixation~1segment, and countermeasures are suggested. The analysis of the inclination characteristics showed that the inclination increased with the segment progresses even in bridges with sufficient safety factor, and the difference before and after the segment was confirmed. In addition, the increase in inclination was related to the loss of tension force in the steel rod, and the stress on the opposite sides of the inclination was further reduced. It is believed that upward tensile force is generated in the steel rod on the opposite side of the inclined side due to the unbalanced moment, causing the difference in stress of the steel rod between the two sides.

• Design Convergence Study
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• v.15 no.3
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• pp.117-131
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• 2016

The introduction of comprehensive programming channels has led to a diversity in the viewers' tastes and excessive competition between TV channels. Demand for channels on well-being is also increasing, due to the well-being and green consumption trends. This study conducted a case study on domestic and international channel branding strategies as well as an analysis on Korean channels focusing on well-being and lifestyle and found that there are no TV channels which provides comprehensive well-being information on food, clothing and housing at the moment in Korea. This study further discovered that information on such topics are currently provided in a tidbit fashion via educational or entertainment programs. Therefore, this study presented strategies for a well-being lifestyle channel brand and designed the brand mark and a station ID for the channel. This study conducted a survey targeting 50 men and women over 20 who have participated in environment-related projects for an objective verification of the channel brand strategies and design. The survey showed that the respondents were generally positive towards the necessity of the channel and of the content presented by this researcher. Some of the respondents, however, pointed out that the readability of the brand mark needs to be improved. This was reflected in the improved design and a survey comparing the two designs showed positive results. The results of this study will contribute to the launch of a well-being lifestyle channel targeting green consumers in the future.

• 한국체육학회지인문사회과학편
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• v.55 no.2
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• pp.643-655
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• 2016

The purpose of this study was to investigate biomechanical differences between young and old adults during downhill walking on a treadmill in order to understand the mechanisms of elderly falls. Eighteen healthy young females(YG: yrs: 21.17±1.5) and eighteen healthy old females(OG: yrs: 66.67±1.33) participated in this study. They were asked to walk at their preferred speed on a treadmill at level, 7.5° and 15° decline. OG walked more wobbly in the medial and lateral directions than YG(p<.05). As slope got steeper, OG had smaller ROM(range of motion) of ankle and knee joints compared with YG. However, there was no difference in ROM of the hip between OG and YG, but maximum extension angle of OG was smaller compared with YG(p<.05). Smaller extensor moment was generated on OG during downhill walking(p<.05). It was hypothesized that more risk factors would be found on older people compared to young people during downhill. However, older people actually walks with a safer strategy compared to young people during downhill. Finally, current findings about biomechanical characteristics of elderly walking would provide useful fundamental information for a follow-up study regarding the prevention of elderly fall during their daily life.

• Earthquakes and Structures
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• v.24 no.6
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• pp.455-475
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• 2023

The present study investigates the non-linear soil-pile interaction using three-dimensional (3D) non-linear finite element models. The numerical models were validated by using the results of extensive pile load and shaking table tests. The pile performance in liquefiable and non-liquefiable soil has been studied by analyzing the liquefaction ratio, pile lateral displacement (LD), pile bending moment (BM), and frictional resistance (FR) results. The pile models have been developed for the different ground conditions. The study reveals that the results obtained during the pile load test and shaking cycles have good agreement with the predicted pile and soil response. The soil density, peak ground acceleration (PGA), slenderness ratio (L/D), and soil condition (i.e., dry and saturated) are considered during modeling. Four ground motions are used for the non-linear time history analyses. Consequently, design charts are proposed depended on the analysis results to be used for design practice. Eleven models have been used to validate the capability of these charts to capture the soil-pile response under different seismic intensities. The results of the present study demonstrate that L/D ratio slightly affects the lateral displacement when compared with other parameters. Also, it has been observed that the increasing in PGA and decreasing L/D decreases the excess pore water pressure ratio; i.e., increasing PGA from 0.1 g to 0.82 g of loose sand model, decrease the liquefaction ratio by about 50%, and increasing L/D from 15 to 75 of the similar models (under Kobe earthquake), increase this ratio by about 30%. This study reveals that the lateral displacement increases nonlinearly under both dry and saturated conditions as the PGA increases. Similarly, it is observed that the BM increases under both dry and saturated states as the L/D ratio increases. Regarding the acceleration histories, the pile BM was reduced by reducing the acceleration intensity. Hence, the pile BM decreased to about 31% when the applied ground motion switched from Kobe (PGA=0.82 g) to Ali Algharbi (PGA=0.10 g). This study reveals that the soil conditions affect the relationship pattern between the FR and the PGA. Also, this research could be helpful in understanding the threat of earthquakes in different ground characteristics.

• 한국노년학
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• v.30 no.4
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• pp.1197-1211
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• 2010

This research was concucted to present a model of advance directives(AD) when a patient, who is in consciousness, shows a preference for an end of life care as an act of preparing for an uncertain situation that may arise in the forseeable future. The subjects of the research are 383 doctors/nurese and adults, who live in six cities and provinces, to investigate the status of AD, attitude regarding a meaningless life-prolonging treatment, and moreover, an understanding of and a preference for AD. The research was done by the well-structured questionnaire. Also, SPSS 14.0 is used to analyse the collected data, focused on frequency analysis, avearage and standard deviation, X2 test. As the results of the study, the most of the surveyed doctors/nurese knew DNR orders and AD and a few of them used DNR orders and AD practically. Also, the result shows that there is a negative conception of meaningless life-prolonging treatment among the responents, in addition, most of them agreed upon the idea of introducing AD to Korea, filling it out and making it legally effective. As a method of making AD out, the respondents wanted to use a form that mixed living will with an Power of Attorney in a document. Also, considering the appropriate time, respondents prefered when they are diagnosed with terminal illness. At the moment, the introductory model for AD, which is suitable for the Korean culture and current situation is presented based on the result of this research. In the future, other researches should deal with specific measures that can lead to a social consensus to adopt AD in Korea.

• Asia Marketing Journal
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• v.12 no.4
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• pp.183-201
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• 2011

In case of Aju capital, it adopted a strategy to use a single brand not two separate brands after M&A was completed. In order to implement this strategy, it has endeavored to effectively process the work of shifting existing marketing infrastructure of DAEWOO capital, the mergee, spending enough transition time for the brand migration. In the process of merging, Aju capital picked the strategy to use the brand of mergee first, which is the Daewoo Capital brand, and then took a transition time for a while to converge to the single brand of Aju capital. Putting another way, even if the M&A deal was completed back in 2005, it maximized the effect of launching its final brand "Aju capital" by capitalizing on the positive image of "Daewoo" during the transition time and changing its name just in the right moment. In a bid to implement this strategy successfully, it established a cautious but sophisticated brand migration strategy. 1) "Brand bridge" strategy through reinforcing brand power of "Naegeron", which is an individual product brand of Daewoo Capital 2) Establishing a good brand image through reinforcing customer satisfaction 3) It implemented and completed its brand transition initiative by going through the step of Aju Capital brand unification (from Sept 09 to present) Currently, the sales unit of Aju Capital is realizing quality growth through specialization. It's strategy is to construct a systematic sales portfolio in terms of both quality and quantity through product-by-product specialization where the existing practice was selling a variety of products in a single branch. Back in 2009, it opened a branch that specialize in imported cars and expanded its used car business to 6 specialized locations. Besides, the specialized locations for personal loan named "Naegeron" was expanded from 3 to 11 locations. Recently, it is expected that it will inject vigor to retail and corporate financing business alongside with its core business, which is auto financing.