• Korean Journal of Child Studies
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• v.18 no.2
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• pp.163-176
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• 1997

Using survey data collected from 275 adolescent children of widowed or divorced single mother families, this study investigated the characteristics of family coping resources, including individual, financial, social, and mother-child relational resources and their effects on the psychological wellbeing of these adolescents. After controlling background variables of the family, higher depression among adolescents was associated with low grade point average, mother's high exposure to negative experiences after loss of father, low attachment to mother, and low sense of self-control. Furthermore, higher grade point average, strong attachment to mother, and high self-control in problem solving were factors predicting higher self-esteem of adolescents. Social network resources were not related to the psychological well-being of the adolescents. Discussion included recommendations for future research. Implications for policy and parent-child relations were discussed with a view to enhancing family functioning of adolescents in single-mother families.

• Journal of Power Electronics
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• v.15 no.4
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• pp.929-938
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• 2015

Maximum power point tracking (MPPT) and battery charging control are two important functions for a solar battery charger. The former improves utilization of the available solar energy, while the latter ensures a prolonged battery life. Nevertheless, complete implementation of both functions can be complex and costly, especially for low voltage application such as standalone street lamps. In this paper, the operation of a solar battery charger for standalone street light systems is investigated. Using only one voltage sensor, the solar charger is able to operate in both MPPT and constant voltage (CV) charging mode, hence providing high performance at a low cost. Using a lab prototype and a solar simulator, the operation of the charger system is demonstrated and its performance under varying irradiance is validated.

• Journal of Korean Physical Therapy Science
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• v.10 no.1
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• pp.158-169
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• 2003

The present study examined that in vivo test is investigated in sham-operated(control group) and aldosterone-analogue deoxycorticosterone acetate (DOCA)-salt hypertensive animals(experimental group) and that the antihypertensive effect was induced by silver spike point(SSP) low frequency electrical stimulation at meridian points(CV-3, -4, Ki-12, SP-6, LR-3, BL-25, -28, -32, -52), specifically, such as diuretic action in 24 hour urine analysis from normal volunteer. The $Na^+$ and $Ca^{2+}$ ions were significantly increased in aldosterone-analogue DOCA-salt hypertensive rats than that in sham-operated rats. However, the $K^+$ ions were significantly decreased in aldosterone-analogue DOCA-salt hypertensive rats than that in sham-operated rats. The current of 1 Hz continue type of SSP low frequency electrical stimulation significantly increased in excretion of urine $Na^+$ and $K^+$ ions from normal volunteer. However, the excretion of $Ca^{2+}$ ion were significantly decreased by SSP electrical stimulation in volunteer. These results suggest that the development of aldosterone analogue-DOCA-salt hypertension is associated with changed $Na^+$, $K^+$ and $Ca^{2+}$ ions of urine. which directly affects blood pressure. Therefore, the hypertension is a risk factor on cardiovascular disease. Moreover, These results demonstrate that the SSP low frequency electrical stimulation, especially current of 1 Hz continue type, significantly regulates $Na^+$, $Ca^{2+}$ and $K^+$ ions from volunteer. Therefore, the SSP low frequency electrical stimulation is a good regulator through a diuretic action of aldosterone-induced hypertension.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.397-400
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• 2015

In this paper a solar energy harvesting system with low-cost MPPT control for low duty-cycled sensor nodes is proposed. The targeted applications are environment, structure monitoring sensor nodes that are not required successively to operate, and MPPT(Maximum Power point Tracking) control using simple circuits is low-cost differently than existing MPPT control. The proposed MPPT control is implemented using linear relationship between the open-circuit voltage of a solar cell. The designed MPPT circuit traces the maximum power point by sampling periodically the open circuit voltage of the solar cell and delivers the maximum available power to the load. The proposed circuit is designed in 0.35um CMOS process. The designed chip area is $975um{\times}1025um$ including pads. Measured results show that the designed system can track the MPP voltage by sampling periodically the open circuit voltage of solar cell.

• Korean Journal of Metals and Materials
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• v.50 no.10
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• pp.753-761
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• 2012

The reduction behavior of low level oxides such as (T.Fe), (MnO) and ($P_2O_5$) in molten EAF slag was investigated using commercial reductants. In an air atmosphere, the slag volume increased and the reduction rate of the slag was very low due to the oxidation loss of reductants by oxygen in the air. The reduction rate of the slag was also low when a commercial reductant was used alone in an Ar gas atmosphere. The reason is probably because the material transfer through the interface between the slag and reductant is difficult due to the formation of high melting point oxide. When reductants were mixed with burnt lime in order to form low melting point reaction products, the reduction rate of the slag increased up to the range of 45-70%. By using the mixtures of reductants and burnt lime so as to form a low melting point slag at the reaction end, the reduction rate of the slag was improved up to 60-85%.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.6
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• pp.542-553
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• 2020

Virtual world and simulation need large scale map rendering. However, rendering too many vertices is a computationally complex and time-consuming process. Some game development companies have developed 3D LOD objects for high-speed rendering based on distance between camera and 3D object. Terrain physics simulation researchers need a way to recognize the original object shape from 3D LOD objects. In this paper, we proposed simply automatic LOD framework using point cloud data (PCD). This PCD was created using a 6-direct orthographic ray. Various experiments are performed to validate the effectiveness of the proposed method. We hope the proposed automatic LOD generation framework can play an important role in game development and terrain physic simulation.

• The Research Journal of the Costume Culture
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• v.11 no.4
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• pp.487-499
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• 2003

The purpose of this study was to suggest marketing strategies to internet fashion shopping malls identifying factors that customers consider important. Data were collected by survey questionnaire and the subjects were 322 men and women in their twenties and thirties living in Seoul and Kyung-gi. SPSS 10.0 package were used and reliability, frequency, cross tabulation, chi-square, paired t-test, ANOV A and Duncan test were conducted for data analysis. The results were as follows. I) Subjects placed the most importance on providing the precise and detail information of products but its satisfaction level was low. 2) Subjects considered the ‘low price’ very importantly but its satisfaction level of it was not high. 3) Subject's importance and satisfaction level of ‘point system’ were about an average. 'Point system' has to be activated by using systems such as 'point network system' by pointbanking co. as one of price-cutting strategies. 4) Internet fashion shopping mall users treated 'the security system of personal data' importantly while they were not sufficiently satisfied with the system. 5) Female placed more importance on design and color of products and suppliance of the trendy items.

• The Journal of Korean Physical Therapy
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• v.12 no.3
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• pp.331-338
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• 2000

Objectives: The objective of this study was to investigate the experience and point prevalence rate and factors related with Low Back Pain (LBP) in bin drivers. Methods: Questionnaires were completed by 200 drivers at 2 bus companies in Andong city in October.2000. The information was used to estimate odds ratio (OR) and $99\%$ confidence intervals (CI) for factors relation to LBP. A cross-section study design was used. Results: The experience rate for LBP was $53.5\%$, point prevalence rate was $31.5\%$. Variables significantly associated with LBP experience were employ duration and stress related occupation. The higher subjects had experienced stress. the higher experience for LBP was (OR=2.9, $95\%$ Cl 1.2-7.2). The longer subjects had employ duration in bus company, the higher experience far LBP was (OR=1.3, $95\%$ Cl 1.2-7.2). Significant factors relation to a week point prevalence far LBP were obesity and employ duration. LBP increased as weight increased (OR=4.1, Cl 1.6-10.7). The longer subjects has employ duration at bus company, the higher LBP is (OR=1.4. $95\%$ Cl 1.6-2.9). Conclusions: Results from this study indicated that a statistically significant factor relation to LBP was stress related occupation. employ duration, and obesity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.6
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• pp.816-824
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• 1999

Design and performance of 18 GHz phase locked dielectric resonator oscillator(PLDRO) for Point-to-point radio link using analog phase locked loop is described which achieve high stability and low SSB phase noise. The module consists of an 18 GHz voltage controlled dielectric resonator oscillator(VCDRO), buffered amplifier, analog phase detector which are integrated to form a miniature hybrid circuit. In addition, containing a low phase noise VHF PLL has been designed to lock any other conventional N times frequency of crystal oscillator. The module achieves stable phase locked state, exhibits output power of 21 dBm at 18.00 GHz, -34 dBc harmonic suppression and -75 dBc/Hz phase noise at 10 kHz offset frequency from carrier.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.437-444
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• 2010

The audio data have been communicated using analog methods or simple protocols. However, with the advent and improvement of various multimedia functions, many audio devices have been integrated into a mobile handset in which interconnection lines are very complicated. Conventional point-to-point connections such as $I^2S$ and PCM demand more power consumption whenever more devices are attached. In this paper, we design a common bus digital audio interface that communicates with only two wires and employs the clock gear method to reduce bus power consumption. The comparison results show that the proposed common bus connection can reduce more than 30% of power consumption as compared with point-to-point connection if more than three devices are connected.