• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.325-328
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• 2020

This paper demonstrated a voltage-controlled oscillator (VCO) using cost-effective (1-poly 6-metal) mixed signal standard CMOS process. To have the high-quality factor inductor in LC resonator with thin metal thickness, patterned-ground shields (PGS) was adopted under the spiral to effectively reduce the ac current of low resistive Si substrate. And, because of thin top-metal compared with that of RF option (2 ㎛), we make electrically connect between the top metal (M6) and the next metal (M5) by great number of via array along the metal traces. The circuit operated from 2.48 GHz to 2.62 GHz tuned by accumulation-mode varactor device. And the measured phase noise of LC VCO has -123.7 dBc/Hz at 1MHz offset at 2.62 GHz and the dc-power consumption shows 2.07 mW with 1.8V supply voltage, respectively.

• Journal of Korea Trade
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• v.23 no.7
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• pp.1-12
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• 2019

Purpose - This paper empirically investigates the relationship between Information and Communication Technology (ICT) goods imports and economic growth with a focus on the 13 Asia-Pacific economies during 2005-2016. In particular, this paper extends the study by breaking down the data of Asia-Pacific countries into High Income Countries (HICs) and Low Income Countries (LICs) according to the difference of income levels. Design/methodology - Our empirical model employs the standard growth model based on the Barro (1998)-type growth framework. Using static panel-data technique, we estimate the effect of ICT goods imports on economic growth in the 13 Asia-Pacific economies. In addition, we also estimate a difference of the ICT goods imports-economic growth link between HICs and LICs. Findings -The estimation results indicate that ICT goods import has a significant positive effect on economic growth, while ICT goods export has a positive but statistically insignificant effect on it. When we break down the panel data into HICs and LICs in order to gain further insight, ICT goods imports has been effective in spurring growth in only LICs but not in HICs. The other supplementary results show that both domestic investment (GCF) and life expectancy (LE) have a significantly positive impact on economic growth in both HICs and LICs. Originality/value - The main findings of the paper suggest that ICT goods imports has a positive effect on economic growth in only LICs but not in HICs. This result supports the so-called 'leapfrogging' hypothesis through ICT goods imports in the Asia-Pacific countries, in which LICs are gaining more from ICT goods imports than HICs.

• Journal of Korea Trade
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• v.25 no.8
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• pp.25-44
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• 2021

Purpose - This research aims to provide empirical evidence that highlights the importance of imported intermediate goods in long-term economic growth. To this end, this paper develops an index that measures the productivity gains associated with a country's intermediate goods imports using highly disaggregated trade data. Design/methodology - The basic hypothesis is that countries sourcing higher-productivity (or higher-quality) inputs from developed economies derive a larger benefit from foreign R&D. To explore this hypothesis, standard cross-country growth regressions are performed using the highly disaggregated data from the United Nations (UN) Commodity Trade Statistics Database (COMTRADE). To address the endogeneity issue, I apply an instrumental variable (IV) approach. Findings - The results of this study demonstrate that the index predicts subsequent economic growth in middle- and low-income countries. This finding is consistent with previous studies that have argued that developing countries can achieve substantial productivity gains by importing intermediate inputs from developed countries. By contrast, there is no evidence of a significant association between the index and economic growth in high-income countries. Originality/value - This paper contributes to our understanding of the causal relationship between international trade and economic growth. From an economic policy perspective, the results suggest that developing countries with limited technology endowment can boost growth from input-tariff liberalization.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.11 no.4
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• pp.6-18
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• 1982

The performance of two typical types of solar hot water heating system was tested in Seoul. Types of systems studied are single-tank internal external heat exchanger system and single-tank internal heat exchanger system. Comparing to experimental results, a transient system simulation program was made to analyze the performance of the selected system. The climate data, Standard Weather Year for Seoul, required for the simulation was provided. Computer simulations were used to estimate the effect of significant parameters upon system performance. The followings are obtained. 1. In the domestic solar water Heating system, the value $20-40kg/m^2\;h$ for flow rate through the collector is much better than the recommended value $72kg/m^2\;h$ in the solar heating system. 2. The effectiveness of collector heat exchanger and storage tank size are found to have only a small effect upon system performance. 3. The hot water draw pattern has a significant effect on system performance. A higher system efficiency achieved when draw-off occurred around noon than when it occurred around early morning. Using the above results, the reference solar hot water system which provides $300\ell$ of hot water per day, was selected as a guide for designer. And simplified graphical method was developed based on the modified f-chart method to determine required collector area. When the system design parameters of the proposed system differs from the reference system, required collector area can be calculated from area adjustment factors.

• Journal of the Korean Society of School Health
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• v.36 no.2
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• pp.31-39
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• 2023

Purpose: Over the past two years, most Korean nursing students had to go through distance learning due to the COVID-19 pandemic. During the pandemic, amental health crisis has emerged among nursing students in South Korea. The study aimed to examine the relationships among social contact, depression, loneliness, and suicidal ideation. Methods: A cross-sectional survey design was used to collect data from nursing students. The survey was conducted onlinein South Korea. A total of 184 nursing students were recruited from December 2021 to April 2022. For data analysis,the frequency, percentage, mean and standard deviation of the general characteristics of the subjects were calculated using IBM/SPSS Statistics 25.0. To examine the mediating effect of depression and loneliness on the relationship between social contact and suicidal ideation, multiple linear regression was used to analyze associations among social contact, depression, loneliness, and suicidal ideation. Results: The average age was 22.69±5.66 years (range=18~54), and the sex distribution was 155 females among 184 nursing students. Lower social contact among nursing students was significantly associated with higher depression and loneliness. Loneliness significantly mediated the relationship between social contact and suicidal ideation innursing students. Conclusion: The findings suggest that strategies for enhancing social contact and reducing depression and loneliness should be considered to improve suicidal ideation among nursing students.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.2
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• pp.101-109
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• 2023

Steel brace strengthening is the most popular seismic rehabilitation method for school buildings. This is because the design can be conducted by using relatively easy nonlinear pushover analysis and standard modeling in codes. An issue with steel brace strengthening is that the reinforced building should behave elastically to satisfy performance objectives. For this, the size of steel braces should be highly increased, which results in excessive strengthening cost by force concentration on existing members and foundations due to the considerable stiffness and strength of the steel braces. The main reason may be the brittle failure mode of columns, so this study investigated the relationship between the efficiency of steel brace strengthening and column failure modes. The result showed that the efficiency is highly dependent on the shear capacity ratio of columns and structural analysis methods. School buildings reinforced by steel braces do not need to behave elastically when the shear capacity ratio is low, and pushover analysis is used, which means reducing steel material is possible.

• Journal of Distribution Science
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• v.22 no.10
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• pp.103-110
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• 2024

Purpose: This study investigated the microbial status of beverages and desserts containing strawberries sold at coffee outlets in Busan, South Korea. The study sought to identify differencesin types of foodservice management and microbial status of beverages and desserts. Research design and methodology: This study compared microbial status between franchised and single-unit outlets via microbial laboratory tests. In addition, impact of risk factors on microbial status were investigated. We analyzed the data using independent t-tests and chi-square tests. In order to measure the impact of risk factors on microbial status, multiple regression was run. We expected franchised outlets to be more likely to apply food safety practices than single-unit outlets. The principal results: Results of microbial testing showed that franchised outlets had a higher microbial status than single-unit outlets. The results showed that franchise outlets were more inclined to adhere to food safety practices than single-unit outlets when it comes to total number of bacteria however for coliform group results showed otherwise. Major conclusions: These study results suggest that a standard food safety and sanitation manual for coffee outlets is needed, especially for single-unit coffee outlets. The current inspection items should be revised accordingly to ensure customer safety.

• East Asian Journal of Business Economics (EAJBE)
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• v.12 no.3
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• pp.25-35
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• 2024

Purpose: The purpose of this paper is to investigate the consumption behavior of consumers more closely and efficient purchasing channels of domestic e-commerce buyers by specifically analyzing the relationship between demographics and channels that are used first to acquire purchasing information during e-commerce. Research design, data and methodology: Korean Media Panel Survey performs 17 cities and provinces nationwide, and 4,537 panel households (all household members aged 6 or older) are surveyed, and a household visit interview is conducted. Correspondence analysis, one of the popular multivariate techniques, is exploited to explore the association between priority channel for acquisition of information and demographics. Results: The findings show that the considered demographics are closely associated with the priority channel for acquisition of purchase information. In particular, 'searching for portal sites' are closely relevant to 'more than 5 million won', 'device & machine control assembly', 'graduate school or higher', and '40-59', while 'searching for online open market' is linked with college graduate and '20-39'. Conclusions: The substantial contribution of this work is that by analyzing the association between demographics and priority channel for acquisition of purchase information in e-commerce in South Korea, we can discern the segmentation standard factor for e-commerce market and advance the subdivided market.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.2 s.161
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• pp.177-188
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• 2007

The purpose of this study was to provide basic materials for the brief patterns and design development for the elderly women to select number 1 to 3 brands according to their brand preference surveying the elderly women with average shapes, and to compare and analyze the exterior fit and functionality. Accordingly, this study proposed basic materials needed for panty pattern suitable for average shapes of the elderly women. The results of the study are as follows: 1 . Looking into the style, they preferred white the best. Regarding the patterns, almost half preferred patterns and rest of them did not. With the panty with patterns, they wanted small and implicit flower patterns. The design they liked was midi, maxi and then mini in order. When looking into the brands, they preferred 'Company B', 'Company SS', 'Company SY', and then market products. The reason why they selected those panty was feeling of fitness, price and then material. 2. To classify the figures of elderly women, we grouped the subjects with strata method using minimal dispersion method. Type 1 is the average, type 2 is for obese women and type 3 is slender women. 3. 3 brands were selected that were produced using CM 40's and elderly women preferred best. When executing wearing test on two elderly women who have average figure according to the body measures in previous study and body measure of Size Korea total exterior evaluation score was Company A, B and C in order.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.136-145
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• 2008

Recently the Ministry of Finance and Economy of Korea launched two new project delivery systems called "Best Value Contract (Design-Bid-Build)" and "Bridging Contract (Design-Build)" in October of 2007 by revising enforcement ordinances of "Act on Contracts to Which the State is a Party". These project delivery systems require the bidders to submit technical proposal adjusted to the project characteristics and objectives for selecting the contractor by evaluating technical proposals. This research aimed to suggest guideline to effectively operate the project delivery systems described above. To reach the goal of the research, the framework of the operation model was developed, which includes the four categories: the standard bidding process, the technical proposal requirements, the technical proposal evaluation criteria, and the award methods. The contents of the four categories above were fulfilled throughout conferring with the advisory experts. In particular, the award methods, which are the important decision-making factor in the perspective of the owner, consist of four types: Low Bid-Fully Qualified, Weighted Criteria, Adjusted Bid, and Adjusted Score. The quantitative features and application criteria of these four types of award methods were suggested throughout the simulation using the virtual case.