• Journal of IKEEE
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• v.23 no.1
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• pp.99-106
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• 2019

This paper propose a new form of UPQC (Unified Power Quality Compensator) to compensate the current and voltage quality problems of nonlinear loads. The conventional UPQC system consists of a series inverter, a parallel inverter, and a common DC link. A new type of UPQC proposed is a parallel compensator with SVC (Static Var Compensator) added to compensate for the wide compensation range and low DC link voltage. The parallel inverter compensates the reactive power generated by the nonlinear load, and the series inverter compensates the sag and swell generated at the power supply side.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.517-527
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• 2021

While the two principles of lean manufacturing and time-driven activity-based costing (TDABC) have been established out of multiple incentives and do not follow the same particular targets, there is substantial commonality between them. In these conditions, the supply management of a multi-product system needs a rigorous production model to minimize costs. In this sense, this paper proposes an interactive model with the consideration of optimizing product-mix decisions using both lean development tools and TDABC. This paper proposes a qualitative approach using the case study of the Iraqi state company for battery production. The suggested model decreased manufacturing time and costs, along with some substantial reduction in idle production capacity by 26 percent in 2019, based on the findings of the case study. On the other hand, the proposed model gives two side advantages: an efficient division of costs on goods due to the use of time spent as a cost factor for products and cost savings due to the introduction of the lean manufacturing approach that reduces all additional costs and increases product-mix decisions. Furthermore, the analytical data gathered here suggests that the incorporation of lean management concepts and TDABC has a strong and important influence on product-mix decisions.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.167-180
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• 2021

The "sharing economy" describes a type of business built on the sharing of resources - allowing customers to access goods when needed. While sharing goods has always been a common practice among friends, family, and neighbors, in recent years, the concept of sharing has moved from a community practice into a profitable business model. This study explores gaps between customers' actual usages and current policies on accommodation sharing by analyzing what needs to be done for the better establishment of sharing economy in society. The purpose of this study is to investigate perceptions of accommodation sharing by analyzing reviews and negative aspects that help resolve complaints and improve better services through policy establishment. This study investigates key attributes that influence business performance to improve citizens' decision-making for the usage of accommodation sharing. This study applies qualitative research by collecting demand- and supply-side reviews from selected registered accommodations using a random sampling procedure. This study finds that guests prefer entire house sharing with instrumental attributes related to properties. Entire house sharing of multiple dwellings shows business impacts in terms of high occupancy rate on the platform, while there are policy concerns with entire house sharing. The results provide policy and managerial implications by suggesting proper policies and considering relationships with citizens.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.12-23
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• 2021

This paper proposes a low power radio frequency receiver front-end where, in a single stage, single-balanced mixer and voltage-controlled oscillator are stacked on top of low noise amplifier and re-use the dc current to reduce the power consumption. In the proposed topology, the voltage-controlled oscillator itself plays the dual role of oscillator and mixer by exploiting a series inductor-capacitor network. Using a 65 nm complementary metal oxide semiconductor technology, the proposed radio frequency front-end is designed and simulated. Oscillating at around 2.4 GHz frequency band, the voltage-controlled oscillator of the proposed radio frequency front-end achieves the phase noise of -72 dBc/Hz, -93 dBc/Hz, and -113 dBc/Hz at 10KHz, 100KHz, and 1 MHz offset frequency, respectively. The simulated voltage conversion gain is about 25 dB. The double-side band noise figure is -14.2 dB, -8.8 dB, and -7.3 dB at 100 KHz, 1 MHz and 10 MHz offset. The radio frequency front-end consumes only 96 ㎼ dc power from a 1-V supply.

• Analyses & Alternatives
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• v.4 no.2
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• pp.71-102
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• 2020

This study analyzes the effect of demographic changes on economic growth. We use the supply-side output identity to forecast the growth potential of the Korean economy. According to the results, even based on optimistic assumptions and prospects, the economic growth rate is likely to fall drastically starting in 2020. Of course, to maintain growth potential, efforts to increase productivity are necessary. However, given the historical experience of developed countries, it is not clear whether the huge trend of demographic change can be offset by efforts to increase productivity. In the so-called '30-50 club' countries, both labor productivity and growth rate tend to fall after reaching the per capita income of $30,000. The degree of decline in the growth rate is closely related to changes in the working age population and the prime-age workforce. The results are similar when tracking the path of changes in total factor productivities of the economy. When a certain level of income is reached, the increase in total factor productivity also tends to slow down. The ripple effects of rapid changes in demographics will indeed be extensive. The negative impact is likely to be concentrated at a time when the working age population, the prime-age workforce, and the total population shrink simultaneously. Above all, it is necessary to use the government's fiscal space to block the possibility of a rapid fall in the growth rate. In addition, it is important to continuously implement various reform tasks that should be promoted, such as improving the education system and strengthening the social safety net.

• Economic Analysis
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• v.26 no.4
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• pp.39-64
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• 2020

Typical business cycle models have difficulties in explaining key macroeconomic labor market variables, such as employment and unemployment, as they usually consider labor hour choices only. In this paper, we introduce labor market search and matching frictions into a New Keynesian nominal rigidity model and estimate it by Bayesian methods to examine the dynamics of the key labor market variables and business cycles in Korea. The results show that unemployment rates are largely explained by technology shocks, which affect the labor demand side, as well as labor supply shocks. In addition, wage bargaining shocks originating from the bargaining process between firms and workers have non-negligible negative effects on output and employment growth, and careful measures need to be taken to limit their adverse effects.

• The Journal of Society for e-Business Studies
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• v.20 no.4
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• pp.193-208
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• 2015

In knowledge based society, information technology (IT) has been playing a key role in economic growth. In recent years, it is surprisingly notable that the source of value creation moved from hardware to software in IT industry. Especially, among many kinds of software products, the economic potential of open source was realized by many government agencies. Open source means software codes made by voluntary and open participation of worldwide IT developers, and many policies to promote open source activities were implemented for the purpose of fast growth in IT industry. But in many cases, especially in Korea, the policies promoting open source industry and its ecosystem were not considered successful. Therefore, this study provides the practical reasons for the low performance of Korean open source industry and suggests the pragmatic requisites for effective open source policy. For this purpose, this study applies soft system model (SSM) which is frequently used in academy and industry as a methodology for problem-solving and we link the problems with corresponding policy solutions based on SSM. Given concerns which Korean open source faces now, this study suggests needs for the three different kinds of government policies promoting multiple dimensions of industry: research and development (R&D)-side, supply-side, and computing environment-side. The implications suggested by this research will contribute to implement the practical policy solutions to boost open source industry in Korea.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.5
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• pp.71-79
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• 2010

This paper presents a design of a LLC resonant controller IC. LLC resonant controller IC controls the voltage of the 2nd side by adjusting frequency the input frequency of the external resonant circuit. The clock generator is integrated to provide the pulse to the resonant circuit and its frequency is controlled by the external resistor. Also, the frequency of the VCO is adjusted by the feedback voltage. The protection circuits such as UVLO(Under Voltage Lock Out), brown out, fault detector are implemented for the reliable and stable operation. The HVG, and LVG drivers can provide the high current and voltage to the IGBT. The designed LLC resonant controller IC is fabricated with the 0.35 um 2P3M BCD process. The overall die size is $1400um{\times}1450um$, and supply voltage is 5V, 15V.

• Journal of Nutrition and Health
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• v.6 no.1
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• pp.39-46
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• 1973

This study was projected to get basic data which can provide a basis for future direction in nutritional education, and also to find the way how to improve the nutritional supply by evaluating the current nutritional intake of average high school students through the survey study of their daily packed lunch. Five hundred twenty seven students from two boys high school and two girls high school including one general and one vocational school respectively were chosen as random sampling technique. Four hundred forty nine among the 527 students had brought lunch. The contents of lunch box were weighed and converted into nutritional values according to the food composition table and compared with recommended dietary allowances. The results compared and classified by sex, School and housewives' educational level were as follows: 1. The nutritional supply in the lunch box was 671 Cal of energy and 22.3 gm of protein for male students which were respectively 55.9% and 74.2% of the dietary recommendations. On the other side female student's lunch boxes were found to contain 495 Cal of energy and 21.3gm of protein which are respectively 61.8% and 80% of the dietary prescriptions. Excluding niacin, all vitamins and minerals were found to be short. 2. Calorie intake in the vocational high school was found to be higher than in the general high school but lower in protein intake especially significant difference (P<0.01) in animal protein. 3. From the nutritional point of view the educational backgrouud of the housewives was not found to have any influence in the way of preparing the lunch boxes. 4. Nutrients of lunch box were heavily inclined to grain rather than to side dishes.

• Korean Institute of Interior Design Journal
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• v.18 no.5
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• pp.101-110
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• 2009

In case of general residential house, photovoltaic can be installed at roof, wall, and any other places. But, in case of apartment building, there has not enough roof space to install photovoltaic panels to supply enough electricity. Actually, apartment building roof and facade wall (exclude the balcony window space) is not enough space to produce and supply the electricity to residents by installing PV panel. Generally, the space of facade balcony with windows in facade wall at apartment building occupied about $70{\sim}80%$, in all facade space. So, if we could use the balcony and windows space in facade as PV to generating electricity, there could contribute the energy saying. But, PV cell is opacify. So if it installed at front window area in apartment building, residents may have displeasure for that opacity character. But the other hand, residents are not always in house especially in day time that is exactly good time for generating electricity by PV. If we can use PV at the facade balcony with window without collusion of resident's displeasure, there have good attraction to using sustainable energy. Hence, this study suggests the design of facade balcony window style PV by considering resident's living pattern in apartment building. The methods of this study are as follows. At first, this study surveyed to the residents about residential time in their home and asked user demand by Delphi survey. At second, this study designed balcony open style PV system which oriented to the user demand. At third, this study tests designed result performance by computer simulation that compared design result with old design. As a result, For the purpose of satisfying the resident demand, there designed sliding window style which slide the several door systems to the one side. That would be make balcony absolute open scenery to the residents. Hence, the designed system performance results were as follows. When we compare the small apartment and large apartment, smaller one has good performance than larger one. Because resident's residential time characteristic. And that has more good electronic performance than vertical style that is similar to roof style.