• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.5
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• pp.238-245
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• 2001

During an AC motor's start-up accelerating period, a large amount of current is required to reach to the rating speed. This is called in-rush current. This peak in-rush current can be more than about several times the operating or steady-state current in the full load rating of the motor. In-rush current is present in both and electronic ballasts. The main area of concern is the tripping of circuit breaker and fuses which can affect electrical system components From this, we can see that the electrical power controllers will be rather concerned, since they have to supply the actual current necessary to start the motor. This paper presents a new method to reducing in-rush current and energy saving of the single-phase induction motor used in air-conditioner. It can be obtained that proposed system is low cost and small size as compared with other controller. Experiments are focused on a capacitor starting single-phase induction motor. The optimal power saving and in-rush current limiting by phase angle control are verified by experimental results. Also, auxiliary winding was controlled by electronic starting switch.

• International Journal of Automotive Technology
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• v.3 no.1
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• pp.41-46
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• 2002

Effect of secondary air injection (SAI) on hydrocarbon reduction has been investigated in a single cylinder Sl engine operating at cold-steady/cold-start conditions. The hydrocarbon emission and exhaust gas temperature with and without catalytic converter were compared with continuous and synchronized SAIs, which injected secondary air intermittently into exhaust port. Effects of SAI location, SAI pressure, SAI timing, and location of catalytic converter have been investigated and the results are compared for both SAls with base condition. At cold-steady condition, the rate of HC reduction increased as the location of SAI was closer to the exhaust valve for both synchronized and continuous SAls. The emission of HC decreased with increasing exhaust-A/F when it was rich, and was relatively insensitive when it was lean. The timing of SAI in synchronized SAI had significant effect on HC reduction and exhaust gas temperature and the synchronized SAI was found to be more effective in HC reduction and exhaust gas temperature compared to the continuous SAI . At cold-start condition, when the catalytic converter was located 20 cm downstream from the exhaust port exit, the catalytic converter warm-up period for both SAls decreased by about 50%, and the accumulated hydrocarbon emission during the first 120 s decreased about by 56% and 22% with the synchronized and continuous SAIs, respectively, compared to that of the base condition.

• Korean Journal of Schizophrenia Research
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• v.22 no.1
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• pp.1-7
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• 2019

Objectives: Clozapine is the drug of choice in treatment-resistant schizophrenia. However, its use is often delayed and a significant proportion of clozapine treated patients fails to respond and experience potentially dangerous side-effects. The aim of this retrospective study was to describe the clinical characteristics of patients started on clozapine and the rate and reason of discontinuation of clozapine. Methods: Medical records of 83 patients started on clozapine during the period of 2012-2016 were reviewed. Results: Clozapine started on patients in chronic phase; the mean age of start was 38.1 years old and the mean number of psychiatric admission was 6.5. A majority (80.7%) of the patients had been subjected to antipsychotic polypharmacy prior to clozapine and most (61.5%) of them were being treated with polypharmacy including clozapine. Overall, 39 (47.0%) subjects had continued clozapine whereas 15 (18.1%) discontinued it; 29 (34.9%) were lost to follow-up. The most common reason for discontinuation was side-effects (n=13) including six life-threatening cases, most of which occurred within 6 months of its start. Conclusion: This study demonstrated that there is some evidence of delays to clozapine use, high rates of polypharmacy and significant rate of discontinuation during the early phase of clozapine treatment.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.143-150
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• 2020

This research is intended to identify how office worker's recognition of strength affects the intention of starting a business when it is used as a medium for utilizing strength. The survey period was conducted for two months from January 17, 2019 to March 8, 2019. In order to achieve the object of this study, a significant number of employees have been collected nationwide, and 287 office workers were analyzed after collecting 300 questionaires, excluding 13 office workers who were not sincere. The significant data were analyzed by utilizing the structural equation and technical statistics and by verifying the conformity of structural model and measurement model and by investigating the relationship between variables. The results of this study are summarized as follows: First, employee's perception of strength has been found to have a significant effect on the utilizing of strength. Second, the use of workers' strengths has been found to have a significant effect on the intention of starting a business. Third, it has been confirmed that in the relationship between the employee's perception of strength and intention to start a business, the recognition of strength has a significant effect on the intention of starting a business only through the use of strength. Most office workers are nervous about the future and make various plans. The time to live after retirement is getting longer and jobs and working hours are shrinking at an alarming rate. According to the analysis on the status of small business owners in the mid-term of 2017 data, the average monthly operating profit of small business owners across the country is decreasing over the years, and most start-ups are subsistence-type start-ups, and they decide to start their own businesses because they have no other choice than start-ups. As the number of small business owners suffering from financial difficulties has increased since the financial crisis and insecurity of job is pushing those with financial difficulties after retirement to the battleground of the start-up market, the result of this research suggest that the workers need to recognize their own strength and enhance the importance of utilizing the strength.

• Journal of architectural history
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• v.25 no.5
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• pp.27-40
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• 2016

The purpose of this study was to comprehend the procurement system of iron materials and the production process of ironwork in royal tombs constructions in the later Joseon period. For this purpose, sixteen Sanneung-uigwes were analyzed. The following conclusions have been reached through the study. First, it was procuring five types of iron materials in constructions of royal tombs. Sincheol had been supplied up to the mid-18th century. On the other hand, the amount of jeongcheol was increased rapidly. Because of the procurement system of initial tools was changed from bokjeong(a kind of tribute) to self-production in the Noyaso. Second, the government stockpiles were utilized as much as possible than bokjeong to manage the limited construction period and sudden construction start. Third, before moving the site of tombs, the melting furnace was installed in the Gungisi(armament factory). The amount of the melting furnace was increased from 5 to 8 since producing the initial tools in the Noyaso. Fourth, six kinds of master artisans were worked in the field of producing ironwork. Metal worker was assigned to one person per melting furnace. Fifth, the quality of final iron materials was controlled by use. Since the 19th century, it had been produced enhanced ironwork.

• Journal of architectural history
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• v.4 no.2 s.8
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• pp.25-44
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• 1995

Bricks are the earliest man-made building materials. Small-size bar bricks were found in use in the Warring States Period(戰國時代) in China. During the Qin(秦) and the Han(漢) Dynasties, brick constructions were built on a larger scale, but most of them were tombs. In case of Korea, bricks were found in use in the Three Kingdoms Period, but also most of them were tombs. Starting from the Unified Silla Period(統一新羅時代), brick gradually became a universal practice to built Buddhist Pagodas with bar bricks. Brick pagodas emergence marked a stage where technological progress made it possible for man to built high-rise brick work, and their dvelopment further perfected masonry technique and enabled building technology to attain new heights. Though from the very start brick pagodas existed side by side with stone pagodas, at the enitial stage they were overshadowed by their wooden counterparts and stone counterparts, because masonry thechiques were then still rather primitive, while woodwork and stonework had already reached a fairly advaced stage. The pagodas in ancient Korea were closely related to the Chinese stupa, which consisted of three parts, namely, the base, the body and the spire. The fact was, soon after the stupas were introduced into Korea, the Korean stupas began to develop features of their own. Korean brick pagodas were made up of a single-storeyed square base, multi-storeyed square body with a small gate, and a steel post with several layers of lotus flower superimposed one on the other.

• Journal of Gifted/Talented Education
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• v.23 no.2
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• pp.237-256
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• 2013

The purpose of this study is to develop program that take a genuine interest in science and motivate students to keep up their study for science gifted children of start period. In this study, we develop and apply the program about sinking and floating for elementary science gifted students, and analyse degree of conceptual change. Students' prior knowledge is analysed for developing the program, and each step is settled about concept of density and buoyancy. Conceptests are arranged into step by step, and we apply the program to 26 science gifted students of 6th grade elementary school. We compare a percentage of correct answers of pre-test and post-test and evaluate Hake gain for analysis of degree of conceptual change. As a result, science gifted students' concepts are changed effectively into scientific concepts by program based on peer instruction for gifted students of start period. And they evaluate the program is novel and useful, also they can be motivated by the program.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.4 s.181
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• pp.75-82
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• 2006

In this paper, we propose an optimal trajectory for biped robots to move up-and-down stairs using a genetic algorithm and a computed-torque control for biped robots to be dynamically stable. First, a Real-Coded Genetic Algorithm (RCGA) which of operators are composed of reproduction, crossover and mutation is used to minimize the total energy. Constraints are divided into equalities and inequalities: Equality constraints consist of a position condition at the start and end of a step period and repeatability conditions related to each joint angle and angular velocity. Inequality constraints include collision avoidance conditions of a swing leg at the face and edge of a stair, knee joint conditions with respect to the avoidance of the kinematic singularity, and the zero moment point condition with respect to the stability into the going direction. In order to approximate a gait, each joint angle trajectory is defined as a 4-th order polynomial of which coefficients are chromosomes. The effectiveness of the proposed optimal trajectory is shown in computer simulations with a 6-dof biped robot that consists of seven links in the sagittal plane. The trajectory is more efficient than that generated by the modified GCIPM. And various trajectories generated by the proposed GA method are analyzed in a viewpoint of the consumption energy: walking on even ground, ascending stairs, and descending stairs.

• Fashion & Textile Research Journal
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• v.19 no.3
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• pp.289-295
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• 2017

This study aims to develop clothing sales forecast system using weather information. As the annual temperature variation affects changes in daily sales of seasonal clothes, sales period can be predicted growth, peak and decline period by changes of temperature. From this perspective, we analyzed the correlation between temperature and sales. Moving average method was applied in order to indicate long-term trend of temperature and sales changes. 7-day moving average temperature at the start/end points of the growth, peak, and decline period of S/S clothing sales was calculated as a reference temperature for sales forecast. According to the 2013 data analysis results, when 7-day moving average temperature value becomes $4^{\circ}C$ or higher, the growth period of S/S clothing sales starts. The peak period of S/S clothing sales starts at $17^{\circ}C$, up to the highest temperature. When temperature drops below $21^{\circ}C$ after the peak temperature, the decline period of S/S clothing sales is over. The reference temperature was applied to 2014 temperature data to forecast sales period. Through comparing the forecasted sales periods with the actual sales data, validity of the sales forecast system has been verified. Finally this study proposes 'clothing sales forecast system using weather information' as the method of clothing sales forecast.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.199-204
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• 2006

The purpose of this work was to evaluate the development of the anammox process by the use of granular sludge selected from a digestion reactor as a potential seed source in a lab-scale UASB (upflow anaerobic sludge blanket) reactor system. The reactor was operated for approximately 11 months and was fed by synthetic wastewater. After 200 days of feeding with $NH_4^+\;and\;NO_2^-$ as the main substrates, the biomass showed steady signs of ammonium consumption, resulting in over 60% of ammonium nitrogen removal. This report aims to present the results and to more closely examine what occurs after the onset of anammox activity, while the previous work described the start-up experiment and the presence of anammox bacteria in the enriched community using the fluorescence in situ hybridization (FISH) technique. By the last month of operation, the consumed $NO_2^--N/NH_4^+-N$ ratio in the UASB reactor was close to 1.32, the stoichiometric ratio of the anammox reaction. The obtained results from the influent-shutdown test suggested that nitrite concentration would be one key parameter that promotes the anammox reaction during the start-up enrichment of anammox bacteria from granular sludge. During the study period, the sludge color gradually changed from black to red-brownish.