• Title/Summary/Keyword: Reduction Model

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Korean Customer Attitudes Towards SNS Shopping

  • Cho, Young-Sang;Heo, Jeong-Yoon;Youn, Myoung-Kil
    • Journal of Distribution Science
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    • v.10 no.8
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    • pp.7-14
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    • 2012
  • As a new format of retailing, social shopping on SNS has rapidly grown in recent. Although there is much literature associated with customer behaviours in the academic world, little attention has been paid to identifying the shopping patterns of SNS shoppers. This paper will, thus, identify how perceived value has an impact on the buying intention of SNS shoppers, after illustrating what kind of factor influences the formation process of perceived value in the Korean marketplace. Given that SNS shoppers are for the most part 20s as well as 30s, the authors handed out questionnaires to them. Furthermore, based on literature review results, the conceptualised research model was developed. Despite lack of literature, the authors developed five constructs like price reduction, quantity- and time-limited message, product ranges, information-sharing, and required number of shoppers. The researchers made a considerable effort to identify the relationship between research concepts and each variable, based on a few research analysis methods such as frequency analysis, the Varimax rotation technique used orthogonal rotation, Cronbach's Alpha, PCA (Principle Component Analysis), and the like. Amongst the 5 variables used to measure the degree of influences on the perceived value as a social shopping characteristic, it has been evident that price cut, required minimum shoppers, product variety, and information-sharing have a positive impact on the perceived value formation processes of SNS customers. Also, this research implies that SNS retailers can differentiate themselves from other retailers by differently using the above factors. From a practitioner's point of view, these factors should be strategically used to increase the social shopping opportunities of SNS users. It is, furthermore, evident that the perceived value formed by the above 4 factors have played an important role in the buying decision process of SNS customers. In a sense, whether customers are aware of higher price cut rates, information-sharing, required minimum shoppers, and product variety has a positive impact on making buying decisions. From a retailer's point of view, online shopping mall operators are able to use blog as well as twitter to improve the buying intention as a marketing tool of social network, because the business activities provided by social shopping retailers, like the rapid, accurate responses to customer requirements, the provision of a variety of information, and the communications between customers are closely related to buying intentions. There are a few research limitations to conduct this empirical research. It was not easy to review prior papers, due to its lack. In spite of the increasing number of SNS shoppers in Korea, little research attention has been paid to this kind of research topic by academicians, because buying products or services through SNS is in its infancy. With regard to research populations, it would be difficult to generalise the research findings in Korea, owing to unbalanced respondent distribution. Considering the above research limitations as well as the growth of social shopping, many authors should pay considerable attention to SNS-related issues in the future, and develop the more sophisticated criteria to measure the characteristics of SNS shoppers.

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A Study on the Improving Fiscal Capability of Local Government -Focusing on the case of zeroing debt policy in Yong-in city (지방정부 재정역량 제고에 관한 사례 연구 -용인시 채무제로화 정책을 중심으로)

  • Choi, Seonmi
    • The Journal of the Korea Contents Association
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    • v.18 no.3
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    • pp.472-485
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    • 2018
  • The purpose of this study is to analyze debt zeroing policy process of Yong-in city based on the Kingdon's Multiple Stream Framework in order to contribute to strengthening financial capacity and competitiveness of local governments. This study focused on the Yong-in case because the city had a local debt of about KRW 800 billion as of 2012, but it completed the debt repayment in early 2017. The results are as follows. First, policy problem streams are the perception of Yongin City's debt indicator, the failure of the LRT project, and the failure of sale of buildinglots of Yukbuk district. Second, in the political stream, there have been the election of new governors, cooperation of local administration and citizens like budget cut. Third, policy alternative streams are the reduction of large-scale investment projects, the expansion of revenues through the sale of idle shared properties, the increase of tax revenues, and the activation of light rail. As the each streams flowed independently, the window of policy change opened by the revitalization of the real estate market and the sale of buildinglots of Yukbuk distric and combined with other policy factors such as the activation of the light rail. In this process, the role of the policy entrepreneurs such as negotiation and persuasion of the related institutions influenced achieving tight fiscal policy. As a result of this policy output, Yongin City achieved zero debt. This study suggests that it is necessary not only the importance of the role of policy entrepreneurs but also of the administrative and citizen cooperation and the institutional complement such as a large scale of the investment review system.

Effect of Cognitive Behavioral Therapy (CBT) for Perinatal Depression: A Systematic Review and Meta-Analysis (산전우울 임부를 위한 인지행동치료 프로그램의 효과: 체계적 문헌고찰 및 메타분석)

  • Shin, Hyeon-Hee;Shin, Yeong-Hee;Kim, Ga-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.271-284
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    • 2016
  • This study was carried out to evaluate the efficacy of CBT for perinatal depression through systematic literature review and meta-analysis. The following databases were used to search the literature: CINAHL, PubMed, EMBASE, Koreamed, Library of Korean Congress, KISS, and Korean Academic Publication Database. Keywords included 'perinatal depression,' 'pregnant women,' and 'cognitive behavioral therapy,' and the evaluated articles were published up to May 2016. Using the R program, the effect size of perinatal depression and anxiety were calculated by random-effects model. The heterogeneity of the effect size was analyzed by data moderator analysis using the meta-ANOVA. Furthermore, the funnel plot, Egger's regression test, fail-safe N, trim-and-fill test, and publication bias analysis were conducted and used to verify the results. Out of the 180 selected articles, 16 clinical trial studies were meta-analyzed. Each articles were evaluated for the risk of bias by the checklist of SIGN; the overall risk of bias was low. The effect size of CBT for perinatal depression was Hedges' g=-0.55 (95% CI: -0.76~-0.33), which was a moderate level, while for anxiety reduction, Hedges' g=-0.20 (95% CI: -0.48~-0.08) and it was not statistically significant. Heterogeneity or risk of publication bias were low. This meta-analytic study found that CBT is moderately effective in reducing perinatal depression in pregnant women.

Analysis of the Optimal Separation Distance between Multiple Thermal Energy Storage (TES) Caverns Based on Probabilistic Analysis (확률론적 해석에 기반한 다중 열저장공동의 적정 이격거리 분석)

  • Park, Dohyun;Kim, Hyunwoo;Park, Jung-Wook;Park, Eui-Seob;Sunwoo, Choon
    • Tunnel and Underground Space
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    • v.24 no.2
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    • pp.155-165
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    • 2014
  • Multiple thermal energy storage (TES) caverns can be used for storing thermal energy on a large scale and for a high-aspect-ratio heat storage design to provide good thermal performance. It may also be necessary to consider the use of multiple caverns with a reduced length when a single, long tunnel-shaped cavern is not suitable for connection to aboveground heat production and injection equipments. When using multiple TES caverns, the separation distance between the caverns is one of the significant factors that should be considered in the design of storage space, and the optimal separation distance should be determined based on a quantitative stability criterion. In this paper, we described a numerical approach for determining the optimal separation distance between multiple caverns for large-scale TES utilization. For reliable stability evaluation of multiple caverns, we employed a probabilistic method which can quantitatively take into account the uncertainty of input parameters by probability distributions, unlike conventional deterministic approaches. The present approach was applied to the design of a conceptual TES model to store hot water for district heating. The probabilistic stability results of this application demonstrated that the approach in our work can be effectively used as a decision-making tool to determine the optimal separation distance between multiple caverns. In addition, the probabilistic results were compared to those obtained through a deterministic analysis, and the comparison results suggested that care should taken in selecting the acceptable level of stability when using deterministic approaches.

Korean Red Ginseng alleviates dehydroepiandrosterone-induced polycystic ovarian syndrome in rats via its antiinflammatory and antioxidant activities

  • Choi, Jong Hee;Jang, Minhee;Kim, Eun-Jeong;Lee, Min Jung;Park, Kyoung Sun;Kim, Seung-Hyun;In, Jun-Gyo;Kwak, Yi-Seong;Park, Dae-Hun;Cho, Seung-Sik;Nah, Seung-Yeol;Cho, Ik-Hyun;Bae, Chun-Sik
    • Journal of Ginseng Research
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    • v.44 no.6
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    • pp.790-798
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    • 2020
  • Background: Beneficial effects of Korean Red Ginseng (KRG) on polycystic ovarian syndrome (PCOS) remains unclear. Methods: We examined whether pretreatment (daily from 2 hours before PCOS induction) with KRG extract in water (KRGE; 75 and 150 mg/kg/day, p.o.) could exert a favorable effect in a dehydroepian-drosterone (DHEA)-induced PCOS rat model. Results: Pretreatment with KRGE significantly inhibited the elevation of body and ovary weights, the increase in number and size of ovarian cysts, and the elevation of serum testosterone and estradiol levels induced by DHEA. Pretreatment with KRGE also inhibited macrophage infiltration and enhanced mRNA expression levels of chemokines [interleukin (IL)-8, monocyte chemoattractant protein-1), proinflammatory cytokines (IL-1β, IL-6), and inducible nitric oxide synthase in ovaries induced by DHEA. It also prevented the reduction in mRNA expression of growth factors (epidermal growth factor, transforming growth factor-beta (EGF, TGF-β)) related to inhibition of the nuclear factor kappa-light-chain-enhancer of activated B cell pathway and stimulation of the nuclear factor erythroid-derived 2-related factor 2 pathway. Interestingly, KRGE or representative ginsenosides (Rb1, Rg1, and Rg3(s)) inhibited the activity of inflammatory enzymes cyclooxygenase-2 and iNOS, cytosolic p-IκB, and nuclear p-nuclear factor kappa-light-chain-enhancer of activated B in lipopolysaccharide-induced RAW264.7 cells, whereas they increased nuclear factor erythroid-derived 2-related factor 2 nuclear translocation. Conclusion: These results provide that KRGE could prevent DHEA-induced PCOS via antiinflammatory and antioxidant activities. Thus, KRGE may be used in preventive and therapeutic strategies for PCOS-like symptoms.

A Study on Evaluation of Ecological Function before and after River Improvement (하천개수 전·후 하천공간의 생태기능 평가방법에 관한 연구)

  • Hong, Il;Kim, Ji-Sung;Shin, Hyoung Sub;Kim, Kyu Ho
    • Journal of Korea Water Resources Association
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    • v.47 no.4
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    • pp.397-409
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    • 2014
  • In this study, the assessment scheme has been developed to evaluate the ecological function of rivers which were changed by the river improvement project. The evaluating factors are composed of physical structure in river channels and ecological connectivity in river areas, and each value of the factors is quantified based on 4 and 2 variables, respectably. This scheme was applied to past (1918, before artificial river improvement) and present Mankyung River area. A GIS model was adopted for calculating, analysing, and presenting river ecological conditions using the 204 grids and 7 reaches in study area. Comparison results show that the evaluation grade was decreased in both factors after river improvement. The main causes of lower grade (from II to IV) for physical structure are the river straightening and crossing structures. The reduction (from II to III) in ecological connectivity grade effected by linear fragmentation due to roads and rails is found to be greater than areal fragmentation due to land-use. In particular, it is also found that a high degree of ecological connectivity in 1918 was distributed along the river, but that one in 2007 showed a tendency to scatter because of the construction of levee and increase of urbanized area.

Establishment of Bus Priority Signal in Real-Time Traffic Signal Control (실시간신호제어시스템에서의 버스우선신호 알고리즘 정립 (중앙버스 전용차로를 대상으로))

  • Han, Myeong-Ju;Lee, Yeong-In
    • Journal of Korean Society of Transportation
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    • v.24 no.7 s.93
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    • pp.101-114
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    • 2006
  • Recently due to the increase of cars and city life, the traffic congestion has worsened. It Is particularly worse in the center of the metropolis. Within the general public means, the public transport buses have the advantage of being more cheap, accessible and mobile. But as there is no separate lane for buses, the collision of cars and buses are creating damage to public service. In order to solve this situation, the bus priority signal system has been introduced to reduce the bus travel time and improve its services. The purpose of this study is to establish bus priority signal algorithm which builds bus efficiency under the real-time traffic signal control system and to analyze the effect of it. As the green time was calculated against real time (under the real-time traffic signal control system), compared to existing bus priority signal there was a reduction in cross street loss. The modified cycle was used to maintain signal progression. A case study was carried out using VISSIM simulation model. In result of this study, we found that there was a decrease in bus travel time despite some evidence of car delays and compared to existing bus priority signal the delay of dishonor could be reduced dramatically. The analysed result of person delay using MOE, is that there is evidence that when bus priority signal is in effect, the person delay is reduced.

Factors Influencing Crash Severity by the Types of Bus Transportation Services Using Ordered Probit Models (순서형 프로빗 모형을 이용한 버스 운송사업 유형 별 사고심각도 영향요인 분석)

  • YOON, Sangwon;KHO, Seung-Young;KIM, Dong-Kyu
    • Journal of Korean Society of Transportation
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    • v.36 no.1
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    • pp.13-22
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    • 2018
  • Buses, one of the representative public transportation modes, are divided into a vareity of service types according to the purpose of operation, operating distance, and management agencies. Although bus-involved crashes may cause large amount of damage due to the higher number of passengers boarded on a bus, prior research has little focused on crash severity according to bus service types. This study aims to investigate factors influencing crash severity in bus-involved crashes and to present policy implications to reduce crash severity by bus service type. To do this, bus-involved crash data from the Traffic Accident Analysis System (TAAS) during five-year period are used. Ordered probit models for three types of bus service, i.e., city bus, suburban and express buses, and charter buses, are estimated to analyze the factors of accident severity. The results show that there are significant differences of factors affecting crash severity among the types of bus services while speed and road surface influence all the types of buses. In case of local buses, time of day, roadway alignment, and installation of a traffic signal are found to be statistically significant factors. Seat belt and road class have significant effects on injury severity of the intercity and express buses. Chartered buses have time of day, driving experience, seatbelt, traffic signal, and day of week as the significant factors. The results of this study are expected to contribute to the reduction of the crash severity by each bus service type.

Rotordynamic Analysis of a Dual-Spool Turbofan Engine with Focus on Blade Defect Events (블레이드 손상에 따른 이축식 터보팬 엔진의 동적 안정성 해석)

  • Kim, Sitae;Jung, Kihyun;Lee, Junho;Park, Kihyun;Yang, Kwangjin
    • Tribology and Lubricants
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    • v.36 no.2
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    • pp.105-115
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    • 2020
  • This paper presents a numerical study on the rotordynamic analysis of a dual-spool turbofan engine in the context of blade defect events. The blades of an axial-type aeroengine are typically well aligned during the compressor and turbine stages. However, they are sometimes exposed to damage, partially or entirely, for several operational reasons, such as cracks due to foreign objects, burns from the combustion gas, and corrosion due to oxygen in the air. Herein, we designed a dual-spool rotor using the commercial 3D modeling software CATIA to simulate blade defects in the turbofan engine. We utilized the rotordynamic parameters to create two finite element Euler-Bernoulli beam models connected by means of an inter-rotor bearing. We then applied the unbalanced forces induced by the mass eccentricities of the blades to the following selected scenarios: 1) fully balanced, 2) crack in the low-pressure compressor (LPC) and high pressure compressor (HPC), 3) burn on the high-pressure turbine (HPT) and low pressure compressor, 4) corrosion of the LPC, and 5) corrosion of the HPC. Additionally, we obtained the transient and steady-state responses of the overall rotor nodes using the Runge-Kutta numerical integration method, and employed model reduction techniques such as component mode synthesis to enhance the computational efficiency of the process. The simulation results indicate that the high-vibration status of the rotor commences beyond 10,000 rpm, which is identified as the first critical speed of the lower speed rotor. Moreover, we monitored the unbalanced stages near the inter-rotor bearing, which prominently influences the overall rotordynamic status, and the corrosion of the HPC to prevent further instability. The high-speed range operation (>13,000 rpm) coupled with HPC/HPT blade defects possibly presents a rotor-case contact problem that can lead to catastrophic failure.

Non-Parametric Low-Flow Frequency Analysis Using RCPs Scenario Data : A Case Study of the Gwangdong Storage Reservoir, Korea (RCPs 시나리오 자료를 이용한 비매개변수적 갈수빈도 해석: 광동댐 유역을 중심으로)

  • Yoon, Sun Kwon;Cho, Jae Pil;Moon, Young Il
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.4
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    • pp.1125-1138
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    • 2014
  • In this study, we applied an advanced non-parametric low-flow frequency analysis using boundary kernel by Representative Concentration Pathways (RCPs) climate change scenarios through Arc-SWAT long-term runoff model simulation at the Gwangdong storage reservoir located in Taeback, Gangwondo. The results show that drought frequency under RCPs was expected to increase due to reduced runoff during the near future, and the variation of low-flow time series was appeared greatly under RCP8.5 scenario, respectively. The result from drought frequency of Median flow in the near future (2030s) compared historic period, the case of 30-year low-flow frequency was increased (the RCP4.5 shows +22.4% and the RCP8.5 shows +40.4%), but in the distant future (2080s) expected increase of drought frequency due to the reduction of low-flow (under RCP4.5: -4.7% and RCP8.5: -52.9%), respectively. In case of Quantile 25% flow time series data also expected that the severe drought frequency will be increased in the distant future by reducing low-flow (the RCP4.5 shows -20.8% to -60.0% and the RCP8.5 shows -30.4% to -96.0%). This non-parametric low-flow frequency analysis results according to the RCPs scenarios have expected to consider to take advantage of as a basis data for water resources management and countermeasures of climate change in the mid-watershed over the Korean Peninsula.