• KIEAE Journal
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• v.14 no.3
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• pp.55-63
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• 2014

This study selected and analyzed filter media that can be applied in non-point pollution reduction devices aimed at processing the source of pollution on site for road runoff that increases rapidly in rainfall-runoff in order to improve the water quality of urban areas. First, the factors that affect the quality of runoff caused by sources of non-point pollution include physical and social factors such as the usage of land around the area of water collection, type of pavement and movement of cars and people, as well as rainfall characteristics such as frequency, intensity, amount and duration of rainfall. Second, the purification tests of the filter media were processed for pH, BOD, COD and T-P, and the filter media showed to have initial purification effect at that items. However, the filter media showed to be very effective for the processing of SS, T-N, Zn and Cd from the beginning to the end. Third, for filter media, zeolite and vermiculite showed to be effective for processing SS, T-N, Zn and CD constantly, and composite filter media including zeolite showed to have strong processing effects. The authors conclude that this study can be applied to technical areas and policies aimed at reducing non-point pollution in urban areas and can also contribute to allowing eco-friendly management of rainfall as well as improvement of water quality.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.4
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• pp.720-722
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• 2015

In this paper, we propose a new type of integrated wireless control system using a cloud-based AP Controller. With this system, network administrator can control wireless network in head office and branch hierarchically. In head office, they have an AP Controller Manager, it can control all Access Points, Access point Controllers in their networks. In addition, if we need to install new Access point Controller because of the increasing number of Access Point, the process of making virtual Access point Controller can be automated. This paper presents an architecture of the integrated wireless control system, as well as describes its components and protocols.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.280-286
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• 2006

Determination method of optimum feeding point for the PIFA type internal antenna for the mobile phone handset was studied. Fundamental theory is that radiated gain is basically depended upon the electric field strength between PIFA conductor and ground plane. Feeding point, slit configuration, material and structure of carrier are main factors fur the PIFA performances. It is shown that maximum electric field strengths of other feeding points decrease in -2dB to -10 dB than optimum point. Ansoft HFSS EM simulator was applied to determine the best feeding point for 2 models of Samsung Electronics mobile phone handset.

• Perspectives in Nursing Science
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• v.12 no.1
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• pp.7-13
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• 2015

Purpose: This observational study was aimed to determine the influence of the Hawthorne effect on the adherence to hand hygiene (HH) among healthcare workers (HCWs) in South Korea. Methods: HCWs were monitored in 2 periods regarding adherence to HH when there were indications for HH. In first period, HCWs recognized that their behavior of hand hygiene being observed (overt observation), and did not recognize in second period (covert observation). Results: The overall difference in HH rate between two periods was 45.0% point (77.8% vs 32.8%). There were significant differences between profession but in nurse aids. The differences in HH rate between two periods were 46.1% point in nurses, 29.9% point in physicians, 64.0% in radiologists, 62.5% point in laboratory technicians, 36.4% point in physio-therapist, and 1.0% point in nurse aids. The Hawthorne effect on the adherence to HH lasted more than 3 months. Conclusion: The Hawthorne effect markedly influence on the adherence to HH regardless of profession except nurse aids. Therefore, Hawthorne effect can be useful tool to improve and sustain the adherence to HH among HCWs in South Korea.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.764-769
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• 2014

This paper describes sheath voltage limiter(SVL) transient characteristics by switching overvoltage considering single point bonding in underground transmission cables. The crossbonding system is generally used for grounding methods of underground transmission system. However, the single point bonding system is used in selective area which is difficult to consist of crossbonding major section. The sheath voltage limiters are connected between joints in the single point bonding. Specially, the high overvoltage might be generated in that section as well as the aging of sheath voltage limiter might be progressed by various electrical stress including lightning overvoltage, switching overvoltage and power frequency overvoltage. Therefore, in this paper, the switching overvoltage characteristics in underground cables are firstly analysed using EMTP simulation. Then, the switching overvoltage of sheath voltage limiter is also studied in single point bonding. Finally, the reduction method of sheath voltage limiter switching overvoltage is proposed by various simulation studies including circuit breaker operating order.

• Journal of Power Electronics
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• v.17 no.3
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• pp.653-663
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• 2017

Multilevel active neutral-point-clamped (ANPC) converter combines the advantages of three-level ANPC converter and multilevel flying capacitor (FC) converter. However, multilevel ANPC converter often suffers from capacitor voltage balancing problems. In order to solve the capacitor voltage balancing problems for five-level ANPC converter, phase-shifted pulse width modulation (PS-PWM) is used, which generally provides natural voltage balancing ability. However, the natural voltage balancing ability depends on the load conditions and converter parameters. In order to eliminate voltage deviations under steady-state and dynamic conditions, the active voltage-balancing control (AVBC) methods of floating capacitors and dc-link capacitors based on PS-PWM are proposed. First, the neutral-point current is regulated to balance the neutral-point voltage by injecting zero-sequence voltage. After that, the duty cycles of the redundant switch combinations are adjusted to balance the floating-capacitor voltages by introducing moderating variables for each of the phases. Finally, the effectiveness of the proposed AVBC methods is verified by experimental results.

• Journal of Oriental Neuropsychiatry
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• v.19 no.1
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• pp.83-95
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• 2008

Objective : The purpose of this study is to compare the effects of Lung, Shenmen, and Endocrine point which were treated with auricular acupuncture therapy to stop smoking. Methods : 120 volunteers who wanted to be treated with auricular acupuncture therapy to stop smoking were divided into three groups; the treatment method for group A consisted of acupuncturing Lung point, group B consisted of acupuncturing Shenmen point and group C consisted of acupuncturing Endocrine point. The treatment was given twice per week for 8 weeks and the changes in amount of daily smoking, desire to smoking, taste of smoking and nicotine dependence as well as subjective symptoms were studied. Results : Statistically, the study showed that changes in amount of daily smoking, desire for smoking, taste of smoking and nicotine dependence were decreased significantly in all groups. Desire to smoke in group B and taste of smoking in group C were markedly decreased. The study of the subjective symptoms showed an improvement. Many participants said that they breathed easier after the treatment and group A had the highest rate. Group B fell asleep easier and Group C improved the appetite. Conclusion : Acupuncturing Lung, Shenmen, and Endocrine point showed the effects on decreasing smoking rates and the effects of individual characteristics. Therefore the acupuncture treatment with 3 points is expected to decrease smoking and to improve the health of smokers.

• Journal of Sensor Science and Technology
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• v.9 no.3
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• pp.153-162
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• 2000

Triple points of high purity materials have been used to calibrate primarily the capsule-type platinum resistance thermometer (PRT) in the temperature range of the triple point of equilibrium hydrogen (13.8033 K) and water (273.16 K). In this work, triple points of Ne, $O_2$, Ar, Hg and $H_2O$ except for the triple point of equilibrium hydrogen were realized to establish the International Temperature Scale of 1990 (ITS-90). At each fixed point, two capsule-type PRTs, which were selected for the international comparison, were tested two times. The combined uncertainties of the realization of each triple point were calculated considering the type A and type B evaluation. In Korea Research Institute of Standards and Science, the combined standard uncertainties of the defining triple Points by the ITS-90 were estimated to about 0.18 mK for Ne, 0.14 mK for $O_2$, 0.14 mK for Ar, 0.24 mK for Hg and 0.11 mK for $H_2O$, respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.1
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• pp.3-14
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• 1991

This thesis investigates influential attributes in clothing purchase through the examination of questionnaire concerning consumer satisfaction at the point of purchase, and clarifies the relationship between consumer satisfaction at the point of purchase and that in wearing. The results are as follows; 1. At interest stage, color, beauty, becomingness and suitability to occasion are influential (in this order): at trial stage, becomingess, color, others' reaction and fit: at adaption stage, color, becomingness, beauty, fit. 2. According to canonical analysis, consumer satisfaction at the point of purchase and that in wearing are closely related. (RCI = .97) It suggests that satisfaction in wearing depends largely on satisfaction at the point of purchase. 3. General satisfaction in wearing is closely related with such factors as predictive expecta-tion, satisfaction at the point of purchase, predictive disconfirmation, normative disconfirrna-tion, and product performance. According to repression results, those factors can explain $79\%$ of satisfaction ill wearing (R = .79). Above all, product performance and normative disconfirmation are highly influential.

• Journal of Power Electronics
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• v.12 no.1
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• pp.164-171
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• 2012

Variable step size maximum power point trackers (MPPTs) are widely used in photovoltaic (PV) systems to extract the peak array power which depends on solar irradiation and array temperature. One essential factor which judges system dynamics and steady state performances is the scaling factor (N), which is used to update the controlling equation in the tracking algorithm to determine a new duty cycle. This paper proposes a novel stability study of variable step size incremental resistance maximum power point tracking (INR MPPT). The main contribution of this analysis appears when developing the overall small signal model of the PV system. Therefore, by using linear control theory, the boundary value of the scaling factor can be determined. The theoretical analysis and the design principle of the proposed stability analysis have been validated using MATLAB simulations, and experimentally using a fixed point digital signal processor (TMS320F2808).