• JSTS:Journal of Semiconductor Technology and Science
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• 제12권1호
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• pp.59-65
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• 2012

A study on the electrical characteristic analysis of solar cell diodes under experimental conditions of varying temperature and frequency has been conducted. From the current-voltage (I-V) measurements, at the room temperature, we obtained the ideality factor (n) for Space Charge Region (SCR) and Quasi-Neutral Region (QNR) of 3.02 and 1.76, respectively. Characteristics showed that the value of n (at SCR) decreases with rising temperature and n (at QNR) increases with the same conditions. These are due to not only the sharply increased SCR current flow but the activated carrier recombination in the bulk region caused by defects such as contamination, dangling bonds. In addition, from the I-V measurements implemented to confirm the junction uniformity of cells, the average current dispersion was 40.87% and 10.59% at the region of SCR and QNR, respectively. These phenomena were caused by the pyramidal textured junction structure formed to improve the light absorption on the device's front surface, and these affect to the total diode current flow. These defect and textured junction structure will be causes that solar cell diodes have non-ideal electrical characteristics compared with general p-n junction diodes. Also, through the capacitance-voltage (C-V) measurements under the frequency of 180 kHz, we confirmed that the value of built-in potential is 0.63 V.

• 공업화학
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• 제9권5호
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• pp.734-741
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• 1998

본 연구에서는 전극전위 분석법을 사용하여 중성운반체로 dibenzo-18-crown-6(D18Cr6)와 valinomycin(Val)을 이용하여 $K^+$ 이온선택성 PVC막 전극의 막과 용액계면에서의 전극특성을 검토하였다. PVC막에서 감응물질(운반체)에 기본전해질의 혼입 (doping)여부, 감응물질의 종류와 함량, 가소제, 막두께 및 이온의 활동도변화에 따른 전극의 기울기, 선형응답범위 한계측정농도 및 방해이온에 따른 선택계수 등 전극특성을 검토하였다. 중성운반체로 D18Cr6, Val을 $K^+$ 이온으로 착체형성하여 사용하였고, 가소제로 dibutylphthalate(DBP), dioctyl sebacate(DOS) 및 dibutyl sebacate(DBS)를, 혼입제인 기본전해질로 potassium tetraphenylborate (KTPB) 및 용매로 THF를 지지체로 PVC를 이용하여 막을 제조하였다. 운반체의 최적 함량은 D18Cr6와 Val의 경우 3.23 wt %이었고, 가소제는 DBP가 가장 적절한 가소제이었다. 막두께에 대한 영향은 최적 막두께 이상에서는 막두께가 얇아질수록 전극특성이 좋아졌으나, 막두께가 이 이하로 얇아지면 운반체의 용출, 막의 강도 등이 작용하여 전극특성이 나빠짐을 알 수 있었다. D18Cr6의 경우 $K^+$ 이온에 대한 혼합용액법에 의한 선택계수 서열은 다음과 같았다: $NH_4{^+}>Ca^{2+}>Mg^{2+}>Na^+$.

• The Journal of Korean Physical Therapy
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• 제26권3호
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• pp.140-146
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• 2014

Purpose: Differences in scapular kinematics and muscle activity appear in the forward head and rounded shoulder posture (FHRSP). Thus, the aim of this study was to investigate the following effects according to different postures on scapular kinematics and muscle activity around scapular region in individuals with and without FHRSP during overhead reaching task. Methods: Thirty pain-free subjects with/without FHRSP participated in this study. All subjects were positioned into three positions: habitual head posture (HHP), self-perceived ideal head posture (SIHP) and therapist-perceived neutral head posture (TNHP). Muscle activities of upper trapezius (UT), lower trapezius (LT) and serratus anterior (SA) were measured during overhead reaching task. Results: Muscle activity of trapezius muscle (UT and LT) during HHP was significantly higher than SIHP and TNHP in FHRSP group (p<0.05), but there was no difference between SIHP and TNHP. SA also significantly increased muscle activity in HHP more than SIHP and TNHP in FHRSP group (p<0.05), but there was no significant difference between SIHP and TNHP. In Non-FHRSP group, although there was a tendency of different muscle activities among three postures, it was not statistically significant. Conclusion: This result demonstrates that muscle activity associated with overhead reaching task is increased in HHP which affects the scapular kinematics and SIHP contributes changed scapular kinematics and proper recruitment of muscle activity in FHRSP similarly to TNHP.

• 대한화학회지
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• 제56권6호
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• pp.720-724
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• 2012

Under pseudo-first order conditions, the monomeric species of Cr(VI) was found to be kinetically active in the absence of phenanthroline (phen) whereas in the phen-promoted path, the Cr(VI)-phen complex undergoes a nucleophilic attack by etane-1,2-diol to form a ternary complex which subsequently experience a redox decomposition leading to hydroxy ethanal and Cr(III)-phen complex. The effect of the cationic surfactant (CPC), anionic surfactant (SDS) and neutral surfactant (TX-100) on the unpromoted and phen-promoted path have been studied. Micellar effects have been explained by considering the preferential partitioning of reactants between the micellar and aqueous phase. Combination of TX-100 and phenanthroline will be the ideal for chromic acid oxidation of ethane-1,2-diol in aqueous media.

• Asian review of World Histories
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• 제2권2호
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• pp.147-167
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• 2014

The urban modernity that became an irresistible model for elites in Asia in the decades before and after 1900 was far from being gender-neutral. It represented an exceptional peak of patriarchy in its exclusion of respectable middle class women from the work force, from ownership and control of property and from politics. Marriage was indissoluble and the wife's role in the male-headed nuclear family was to care for and educate the abundant children she produced. Puritan religious values underlined the perils for women of falling outside this pattern of dependence on the male. Though upheld as modern and civilized, this ideal was in particularly striking contrast with the pre-colonial Southeast Asian pattern of economic autonomy and balance between women and men, and the relative ease of female-initiated divorce. Although attractive to many western-educated Southeast Asian men, including religious reformers determined to 'save' and domesticate women, urban respectability of this type was a poor fit for women accustomed to dominant roles in commerce and marketing, and at least equal ones in production. Southeast Asian relative failure in the high colonial era to adapt to the modern market economy may also have a gendered explanation. We should not be surprised that patriarchy and puritanism became more important in Southeast Asia as it urbanized in the late 20th Century, since this was echoing the European experience a century earlier. The question remains how far Southeast Asia could retain its relatively balanced gender pattern in face of its eventual rapid urbanization and commercial development.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.690-695
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• 2000

This article deals with the analytic results on the development and application of the Spherical CVT. The Spherical CVT is marked by its simple configuration, the infinite torque multiplication characteristic, and the smooth transitions between forward/neutral/reverse states of output speed. In this study, we describe the conceptual principles behind the Spherical CVT and some applications of it, which we developed recently. And, we propose the shifting algorithm based on the analytic consideration of CVT powertrain system. Contrary to conventional shifting algorithms using the OOL(optimal operating line) of the power source, the proposed shifting algorithm is represented as a $2^{nd}$ order equation in an explicit form, and it reveals the possibility of theoretic design of all optimal controller. As an example, we present numerical results that demonstrate the energy saving possible and the proposed shifting algorithm from the use of the Spherical CVT over standard reduction gear unit, using an ideal dc motor model.

• International Journal of Oral Biology
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• 제40권3호
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• pp.135-141
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• 2015

Biofilms of oral microbes can cause various diseases in the oral cavity, such as dental caries, periodontitis and mucosal disease. Electrolyzed water generated by an electric current passed via water using a metal electrode has an antimicrobial effect on pathogenic bacteria which cause food poisoning. This study investigated the antimicrobial activity of electrolyzed waters using various metal electrodes on the floatage and biofilms of oral microbes. The electrolyzed water was generated by passing electric current using copper, silver and platinum electrodes. The electrolyzed water has a neutral pH. Streptococcus mutans, Porphyromonas gingivalis and Tannerella forsythia were cultured, and were used to form a biofilm using specific media. The floatage and biofilm of the microbes were then treated with the electrolyzed water. The electrolyzed water using platinum electrode (EWP) exhibited strong antimicrobial activity against the floatage and biofilm of the oral microbes. However, the electrolyzed water using copper and silver electrodes had no effect. The EWP disrupted the biofilm of oral microbes, except the S. mutans biofilm. Comparing the different electrolyzed waters that we created the platinum electrode generated water may be an ideal candidate for prevention of dental caries and periodontitis.

• Clinical Nutrition Research
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• 제5권3호
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• pp.172-179
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• 2016

Acid food indicators can be used as pH indicators for evaluating the quality and freshness of fermented products during the full course of distribution. Iron oxide particles are hardly suspended in water, but partially or completely agglomerated. The agglomeration degree of the iron oxide particles depends on the pH. The pH-dependent particle agglomeration or dispersion can be useful for monitoring the acidity of food. The zeta potential of iron oxide showed a decreasing trend as the pH increased from 2 to 8, while the point of zero charge (PZC) was observed around at pH 6.0-7.0. These results suggested that the size of the iron oxide particles was affected by the change in pH levels. As a result, the particle sizes of iron oxide were smaller at lower pH than at neutral pH. In addition, agglomeration of the iron oxide particles increased as the pH increased from 2 to 7. In the time-dependent aggregation test, the average particle size was 730.4 nm and 1,340.3 nm at pH 2 and 7, respectively. These properties of iron oxide particles can be used to develop an ideal acid indicator for food pH and to monitor food quality, besides a colorant or nutrient for nutrition enhancement and sensory promotion in food industry.

• Journal of Information Science Theory and Practice
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• 제9권3호
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• pp.14-30
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• 2021

Data innovation is at the core of the Fourth Industrial Revolution. While the catastrophic COVID-19 pandemic has accelerated the societal shift toward a data-driven society, the direction of overall data regulation remains unclear and data policy experts have yet to reach a consensus. This study identifies and examines the ideal regulator models of data-policy experts and suggests an appropriate method for developing policy in the data economy. To identify different typologies of data regulation, this study used Q methodology with 42 data policy experts, including public officers, researchers, entrepreneurs, and professors, and additional focus group interviews (FGIs) with six data policy experts. Using a Q survey, this study discerns four types of data policy regulators: proactive activists, neutral conservatives, pro-protection idealists, and pro-protection pragmatists. Based on the results of the analysis and FGIs, this study suggests three practical policy implications for framing a nation's data policy. It also discusses possibilities for exploring diverse methods of data industry regulation, underscoring the value of identifying regulatory issues in the data industry from a social science perspective.

• 천문학회보
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• 제45권1호
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• pp.63.2-63.2
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• 2020

FLASH is a blind neutral hydrogen (HI) absorption line survey, eventually targeting about 100,000 background radio continuum sources in the entire southern sky using the full 36-antenna of the Australian Square Kilometre Array Pathfinder (ASKAP). Our primary goal is to search for associated and intervening HI absorption lines in the intermediate redshift range 0.4 < z < 1.0. The survey aims to understand the evolution of HI gas in galaxies as well as various physical mechanisms in active galactic nuclei, such as accretion and feedback processes. In this poster, we give an overview of the FLASH survey and present the preliminary results from our first 100-hrs of pilot observations. The latest survey data covers 1,000 square degrees and is ideal for validating observation and data processing in the continuous 300MHz-width low frequency ASKAP band (700-1000MHz). One of the crucial objectives of the pilot survey is to establish the analysis methodology that will be applied to upcoming large absorption surveys in the future. We discuss our data quality validation and present some detections of associated/intervening HI absorption lines. These absorption lines allow us to trace the cold gas properties of active and normal galaxies at higher redshifts where the HI emission line is too weak to be detectable.