• Journal of Radiation Protection and Research
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• v.10 no.2
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• pp.89-95
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• 1985

An alternative estimator for dose equivalent was derived. The original LET distribution concept was transformed into a charged particle fluence spectrum concept along with the definition of an average quality factor named slowing-down averaged quality factor by adopting the continuous slowing down approximation. With the alternative estimator, the dose equivalent delivered into a receptor located in a given radiation field can be directly and conveniently estimated in a Monte Carlo procedure. The slowing-down averaged quality factors for the energy range below 10 MeV were evaluated and tabulated for the charged particles which may be generated from the interactions of neutron with the nuclei composing soft tissue.

• Journal of the Korean Home Economics Association
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• v.34 no.5
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• pp.1-12
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• 1996

The purpose of this study was to develop the Self-Esteem Inventory for Children in Korea. The 772 subjects were selected from 3rd-6th grades of elementory schools and the first and second grades of middle schools in Pusan. Statistics used for data analysis were Pearson's r, Cramer's V, X2, factor analysis, multi-regression, splithalf reliability, Cronbach's α. The major findings were that 1) eight factors(home self, personality self, academic self, teacher-related self, general self, physical-appearance self, peer-related self, physical-competence self) were extracted by factor analysis, multi-regression analysis conducted to reduce the iength of inventory have drawed 38 items for the Self-Esteem Inventory for Children in Korea. 2) the discriminant coefficients of the items (Cramer's V) ranged from 0.55 to 0.67. 3) the reliability coefficients of this inventory (Cronbach's α) ranged from 0.63 to 0.81. It was concluded that Self-Esteem Inventory for children is acceptable.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.20-25
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• 1998

This paper presents an algorithm for contingency ranking using line outage distribution factors(LODF) which are established by generation shift distribution factors(GSDF) from DC load flow solutions. By using the LODF, the line flow can be calculated according to the modification of base load flow if the contingency occur. To obtain faster contingency ranking, only the loading line more than 35[%](60[%] at 154[kV]) is included in the computation of Performance Index(PI). The proposed algorithm has been validated in tests on a 6-bus test system.system.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.249-250
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• 2015

가변 인덕터를 사용한 고효율 임계 도통 모드 (CRM) 부스트 power factor corrector (PFC) 을 제안한다. 입력 전압에 따라 부스트 인덕턴스 ($L_B$) 을 변화시킴으로써 고효율이 요구되는 $230V_{ac}$의 노미날 입력 전압에서 스위칭 손실을 줄일 수 있다. 가변 인덕터는 코어에 충분한 직류 전류가 흐를 때 투자율이 변하는 코어 본연의 성질을 이용해 구현 가능하다. 노미날 입력시에는 큰 $L_B$을 갖음으로써 스위칭 손실을 줄일 수 있다. $255V_{ac}$ 이상의 큰 입력 전압이 들어오는 경우에는 인덕턴스를 줄여준다. 실험을 통해 제안한 컨버터의 성능을 검증하였다.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.232-233
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• 2012

This paper presents an effective control scheme for an electric vehicle battery charger where a symmetrical bridgeless power factor-corrected converter and a buck converter are cascaded. Both converters have been popular in industries because of their high efficiency, low cost, and compact size, hence combining these converters makes the overall battery charging system strongly efficient. Moreover, this charger topology can operate at universal input voltage and attain a desired battery current and voltage without ripple. In order to achieve a unity input power factor and zero input current harmonic distortion, the proposed control scheme adopts duty ratio feed-forward control technique in both current and voltage control loop. Additionally, in the current loop, its reference is created by a phase-locked loop (PLL) block, leading to a pure sinusoidal input current although the input voltage waveform is being distorted. The feasibility and practical value of the proposed approach are verified by simulation and experiment with an 110V/60Hz ac line input and 1.5kW-72V dc output of the battery charging system.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.5049-5053
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• 2014

Background: To investigate the expression of CD44v3 and vascular endothelial growth factor-C (VEGF-C) and their relationship with lymph node metastasis in squamous cell carcinomas (SCC) of the uterine cervix. Materials and Methods: Expression of CD44v3 and VEGF-C was analyzed in 109 cases of cervical SCC by immunohistochemistry (IHC). The relationship was analyzed between expression and the patient age, histological differentiation, formation of tumor emboli in lymphoid vessels, lymph node metastasis, FIGO staging, and TNM classification. Results: Expression rates for both CD44v3 and VEGF-C were 43.1% in cervical SCC. The cells with positive immunohistochemical staining of CD44v3 were distributed mainly around the keratin pearls in well differentiated carcinomas, but distributed diffusely in the moderately and poorly differentiated lesions. VEGF-C was found stained positively in most of the tumor cells. There were differences in expression between normal epithelium and atypical hyperplasia as well as carcinoma. Both CD44v3 and VEGF-C were found to be associated positively with lymph node metastasis and TNM classification (both p=0.000). Neither CD44v3 nor VEGF-C was found to be associated with patient age, histological differentiation, formation of tumor emboli in lymphoid vessels and FIGO staging. CD44v3 was found to be associated with VEGF-C positively (p=0.000). Conclusions: Abnormal expression of CD44v3 and VEGF-C is associated closely with the lymph node metastasis in cervical SCC, and these agents may cooperate in carcinogenesis and development of metastatic lesions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.746-752
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• 2020

As environmental issues have been taken seriously, the number of solar power generation facilities has rapidly increased in Korea. The voltage at the output stage of an inverter increases in a system that connects a small-capacity photovoltaic power generation to low-voltage power distribution. This degrades the quality of the low-voltage distribution system and adversely affects the load facility. In this study, a solution was obtained to increase the voltage at the output stage of the solar inverter according to the connection of the low-voltage distribution system. The voltage can be controlled by using reactive power factor control inverters. If the secondary tap is adjusted, the voltage can be adjusted to about 15 V, but there is a problem in that the tap is not adjusted unless the KEPCO distribution regulation voltage is out of the range of 220±13V. If the number of inverters is limited, the inverter can be started within the inverter overvoltage range. If it is connected to three phases, the voltage is distributed. The results indicated that power factor control and active voltage control inverters were easy to apply in the field.

• Journal of Radiation Protection and Research
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• v.21 no.4
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• pp.297-311
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• 1996

ANSI decided PMMA slab phantom as a calibration phantom and introduced a conversion coefficient calculation method for it. For photon, the conversion coefficient can be obtained by using backscatter factor and conversion coefficient of the ICRU tissue cube and backscatter factor of the PMMA slab. For neutron, however, the ANSI has not introduced any conversion coefficient calculation method for the PMMA slab. In this work, the ANSI method for the photon conversion coefficient calculation was applied to the neutron conversion coefficient calculation of the PMMA slab. Quality weighted tissue kerma of neutron was applied to calculate the backscatter factors on the ICRU cube and the PMMA slab. The dose conversion coefficient of the ICRU cube was also calculated by using MCNP code. Then, the dose conversion coefficient of the PMMA slab was calculated from two backscatter factors and the dose conversion coefficient of the ICRU cube. The discrepancies of the dose conversion coefficients of the PMMA slab and the ICRU cube were less than 10% except 1eV(20%), 1keV(17%), and 4 MeV(16%).

• The Journal of Pediatrics of Korean Medicine
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• v.17 no.2
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• pp.37-53
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• 2003

Objective : To find risk factor and symptoms for transferred newborn from postpartum care center Method : We performed a follow-up study using medical record. Subjects comprised 188 neonates(include 4 twins) and 184 women in childbed who were hospitalized in oriental postpartum care center from January, 1, 2002 to December, 31, 2002. Result: Transferred newborn was total 24, N.V.D. 17, C.S. 7, male and female were 12 separately. The symptom of transfer was fever(16), diarrhea(4), jaundice(3), convulsion(1) Transferred number and rate was male 12(10.7%), female 12(15.8%). In delivery method, total normal vaginal delivery(N.V.D.) was 136 and transferred 17(12.5%), total cesarean section(C.S.) was 52 and transferred 7(13.5%). Transferred rank was N.V.D. female(17.9%). C.S. male(15.6%), C.S. female(10%), N.V.D.(8.6%). Of the 188 neonates. immature infants were 2 and transferred 1(50%), term infants were 184, transferred 23(12.5%), post-term infants were 2 and transferred none(0%). In age of women in childbed, transferred ratio was 15.4%(over 35), 15.2%(25-29), 10.5%(30-34). In fever,. C.S. infants were more transferred than N.V.D. and male infant had a tendency to transfer in later period of hospitalization and female in early period. It seems that transfer was related to abortion. In diarrhea, all was N.V.D. and their diagnosis was rotavirus. The average age of women in childbed was yonger(28.5). In jaundice, all was 1st, and average birth weight was lighter(3153g). The average age of women in childbed was older(30). In convulsion, birth weight was lighter(3153g), and age of women in childbed was older(30). Conclusion : There's any relation with sex and delivery method, birth weight and mother's age in transfer. But we cannot find any statistically significance. Further prospective studies are needed to find risk factors in transfer.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.176-183
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• 2000

In this paper, sixth order hannonic injected PWM for improving‘ input CWTent distortion of single switch t three phase boost converter is presented. Peliodic sixth order hmmonic ${\gamma}$oltage is inj<:ded in the control circuit t to var${\gamma}$ the duty ratio of the converter switch within one switching cycle. In the result, the input phase c currents are forced to track the input voltage and an 해most unity power factor is obtained. Expelimental r results are verified by converter operating at 400V /6kW with three phase 140V ~220V input and by C02 arc w welding machine which was nonlinear load with 3 $\phi$ 220V input.