• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.415-417
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• 1989

In this paper we introduce electrical and mechanical properties of PPLP, an insulation system of Cellulose/Extruded Polypropylene/Cellulose Paper, and characteristics of 345KV O.F cable employing the PPLP. This cable shows dielectric loss less than 50% and has excellent impulse breakdown strength higher than 17%, respectively, compared with those of the conventional cables. Accordingly, a more compact cable with reduced thickness of the insulation layer, which has remarkable profits in economics, has been developed.

• 설비공학논문집
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• 제21권6호
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• pp.340-346
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• 2009

This paper numerically investigates thermo-flow characteristics of offset strip fins to obtain a correlation between heat transfer and pressure drop. The flow was divided into three regimes, i.e. laminar, transition and turbulent. The predicted j and f values from the SST k-$\omega$ turbulence model agreed with previous correlations with the error less than 20% in transition and turbulent regimes. Heat transfer and pressure drop were predicted by varying Prandtl number from 0.5 to 40. The Prandtl number showed little effects on pressure drop but had great effect on the heat transfer characteristics. An overall correlation to predict j was suggested by incorporating the effect of Pr and a new j correlation was suggested for each Pr.

• 전기화학회지
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• 제5권4호
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• pp.192-196
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• 2002

Ionic liquids based on l-ethyl-3-methylimidazolium cation $(EMI^+)$ and inorganic or organic anions containing fluorine atoms were applied to electrolyte materials for double-layer capacitors. The double-layer capacitors composed of a pair of activated carbon electrodes and an ionic liquid selected from $EMIBF_4,\; EMINbF_6,\;EMITaF_6,\;EMICF_3SO_3,\;EMI(CF_3SO_2)_2N,\;and\;EMI(C_2F_5SO_2)_2N$ showed inferior low-temperature characteristics to those of a conventional nonaqueous electrolyte based on propylene carbonate (PC) solvent. On the other hand, the capacitor using $EMIF{\cdot}2.3HF$ showed excellent low-temperature characteristics due to its high conductivity at low temperatures, however, it had a lower working voltage $(\~2V)$ than the conventional nonaqueous counterpart $(\~3V)$.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.233-238
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• 2008

This paper numerically investigates thermo-flow characteristics of offset strip fins to obtain a correlation between heat transfer and pressure drop. The flow was divided into three regimes, i.e. laminar, transition and turbulent. The predicted j and f values from the SST k-$\omega$ turbulence model agreed with previous correlations with the error less than 20% in transition and turbulent regimes. Heat transfer and pressure drop were predicted by varying Prandtl number from 0.5 to 40. The Prandtl number showed little effects on pressure drop but had great effect on the heat transfer characteristics. An overall correlation to predict j was suggested by incorporating the effect of Pr and a new j correlation was suggested for each Pr.

• 화훼연구
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• 제17권3호
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• pp.179-184
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• 2009

페튜니아 5개 계통을 이면교배한 $F_1$ 10개 조합 및 양친에 대한 성 관련 형질인 초장, 초폭, 줄기길이, 줄기수, 절간장, 엽수 및 개회수 등의 형질에 대하여 상호관계 및 조합능력을 분석하였다. 초장은 초폭, 절간장 및 개회수 등의 형질들과, 엽수는 초폭, 줄기수 및 개회수의 형질들과 유의성이 인정되었으며, 특히 초폭과 절간장과의 사이에 고도로 유의한 정의 상관관계를 보였다. 일반조합능력(GCA)은 초장, 초폭, 줄기길이, 절간장, 줄기수, 엽수 및 개화수 등 모든 조사 형질에서 유의성이 인정되었고, 특수조합능력(SCA) 초폭, 줄기수, 엽수 및 개화수 등의 형질에서 유의성이 있었고, 일반조합능력효과가 특수조합능력효과보다 크게 작용하였다. 모본의 일반조합능력검정에서 D계통은 초 장, 초폭, 줄기길이, 줄기수, 엽수 및 개회수의 증가를 위해서, I계통은 초폭, 줄기길이 절간장에 대하여 일반 조합능력이 큰 것으로 나타났다. 특수조합능력 검정에서 초폭 증가에 뚜렷한 유의성을 보인 조합은 $D{\times}I$, $F{\times}I$와 $G{\times}I$조합이었고, 초폭, 절간장 및 개회수를 동시에 증가시키는데 유의성을 보인 조합은 $G{\times}I$조합이었다. 광의의 유전력은 7가지 형질 모두 크게 나타났고, 초폭과 줄기길이 및 절간장은 협의의 유전력도 높게 나타났다.

• 척추신경추나의학회지
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• 제5권1호
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• pp.11-22
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• 2010

Object: This study was planned to show the physical characteristics of soccer player and their Yangdorak measurements. Method: We categorized 5 study group. (I-Players classified by age; II, III-Players and control group; IV-Players who had positive RF and the others; V-Players who had digestive disorder and the others) And We conducted the potentiality of skin resistance(Yangdorak) and GFS, PFT, ECG and the other, then analysis that. Result: As old aged group, Yangdorak shown lower RS, but that was not significant. Player group had higher Yangdorak score at H5, F1, F2, F5 than control group. Player group was shown better cardiopulmonary function, but H1, H2, H3 score were not significant. Players who conducted RF test shown not significant difference of H4 measurement between positive and negative group. Digestive disorder group had higher F1, F6 score, but that wasn't significant.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2003년도 10월 학술대회지
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• pp.55-58
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• 2003

The purpose of this paper was to analyze the effects of nasalization on vowels. Ten males and 7 females produced 5 vowels (/a/, /e/, /i/, /o/, /u/) in conditions: normal and nasalized. In this study we compared normal vowels' formant with nasalized vowels' and examined nasal-formant in the nasalized vowels. The results was as follows: First, there was a significant difference between normal vowels and nasalized in terms of F1 and F2. Second, the nasal formants were observed in nasalized vowels more frequently in females than males. Third, N1 appeared to influence F1 of vowels whereas N2 seemed to have an impact on F2 and/or F3.

• 센서학회지
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• 제11권1호
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• pp.9-17
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• 2002

X-선 저장 형광체 $BaFBr_{1-x}I_x:Eu^{2+}$, $Na^+$의 조성 조건을 조사하고, 제조한 형광체의 광자극발광 강도, 스펙트럼, fading 특성 및 선량의존성을 조사하였다. 그리고 이 특성을 상업적으로 시판하고 있는 일본 부사(富士)사진필름회사 제품 영상판(ST-III)의 특성과 비교하였다. $BaFBr_{1-x}I_x:Eu^{2+}$, $Na^+$ 형광체의 최적 제조 조건은 $Eu_F3$ 0.5mol%, NaF 4.0mol% 그리고 조성비 x=0.3 이었으며, 소결온도는 수소 분위기에서 $950^{\circ}C$이었다. 조성비 x=0일 때 $BaFBr_{1-x}I_x:Eu^{2+}$, $Na^+$ 형광체의 스펙트럼영역은 $365{\sim}420\;nm$이었고, 최대 발광강도는 390 nm 이었다. $x{\neq}0$일 때 스펙트럼의 파장영역과 피이크 파장은 조성비 x가 증가할수록 장파장쪽으로 이동하였다. X-선 조사선량과 PSL 강도 사이에는 좋은 직선성을 나타내었다. 형광체의 fading 특성은 x=0.3일 때 가장 좋았으며, $I^-$ 이온의 농도가 증가할수록 저하되는 경향을 나타내었다. 또한 $BaFBr_{1-x}I_x:Eu^{2+}$ 격자상수는$I^-$이온의 농도가 증가할수록 커졌다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2131-2136
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• 2008

The characteristics of heat transfer and pressure drop in an offset strip fin heat exchanger was studied with a steady-state three dimensional numerical model. Flow Reynolds number $Re_{dh}$ ranged from 10 to 3500 and Prandtl number Pr ranged from 0.7 to 50. The dimensionless performance factors, i.e. 'the pumping power factor F' and 'the heat transfer performance factor J' were analyzed and obtained a relationship between them. Finally, the prediction of F and J factors was generalized for different Prandtl numbers.

• 동력기계공학회지
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• 제13권6호
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• pp.51-56
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• 2009

Recently, lots of researchers have been attracted to develop various alternative fuels in diesel engine. The use of biodiesel fuel(BDF) is an effective way of substituting diesel fuel in the long run. But biodiesel fuel can affect the performance and emissions in diesel engine because it has different chemical and physical properties from diesel fuel. In this study, to investigate the combustion characteristics of biodiesel fuel as an alternative fuel for D.I. diesel engine, experiments were carried out at the three-cylinder, four stroke D.I. diesel engine with T/C. As a result, shorter ignition delays were observed for the biodiesel blend cases relative to the diesel oil. The pick value of premixed combustion for the rate of heat release is increased with decreasing C.F.W. temperature.