• 한국식생활문화학회지
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• 제31권2호
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• pp.178-187
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• 2016

The principal objective of this study was to investigate the quality characteristics of Yukwa prepared with chlorella powder. The tested concentrations of chlorella powder were 0, 1, 2, and 3%. As more chlorella powder was added, spread ratio, moisture content, and volume increased, whereas L-value and a-value decreased and b-value increased. The hardness of Yukwa made with 3% chlorella powder was highest among the samples. The results of the sensory evaluation test show that Yukwa with 1% chlorella powder was significantly more preferable in term sof overall acceptability. The acid value and peroxide values were lower in Yukwa prepared with chlorella powder than the control. Yukwa prepared with chlorella powder showed strong inhibition of lipid oxidation. Thiobarbituric values were lower in Yukwa prepared with 2% chlorella powder compared to Yukwa prepared with 1% and 3% chlorella powders and control Yukwa. These results suggest that chlorella powder can be applied to Yukwa for high quality and functionality.

• 한국식품영양과학회지
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• 제31권5호
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• pp.738-742
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• 2002

단감빵을 개발하기 위하여 강력분을 단감가루로 대체할 수 있는 적정 비율을 결정하고, 단감가루 대체 비율별 단감빵의 물리적, 관능적 검사를 통하여 단감빵의 품질 특성을 살펴본 결과는 다음과 같다. 강력분 대신 단감가루를 5, 10, 15, 20% 대체했을 때 단감가루의 비율이 증가함에 따라 수분 흡수율과 빵의 부피는 감소하고 빵의 무게는 증가하였다. 식이섬유나 비타민 A, $\beta$-카로틴, 비타민 C 함량은 밀빵보다 단감빵에 훨씬 많았으며 단감가루 대체율이 증가할수록 증가하였다. 색도는 단감가루의 비율이 증가할수록 빵 껍질색에서 L, b값은 감소하였지만 a값은 증가하였고, 빵 내부색에서는 L값만 감소하고 a, b값은 증가하였다. 기호도 검사에서 외관을 제외한 풍미, 조직감, 전반적인 기호도에서는 10% 단감빵이 밀빵보다 선호되었고, 맛에서는 5% 단감빵이 가장 점수가 높았고, 10% 단감빵이 그 다음으로 나타났다. 관능검사QDA결과 단감가루 대체 비율이 증가할수록 껍질색, 내부색, 단감향, 갈변취, 단맛, 뒷맛, 탄력성, 점착성은 증가하였다. 단단함은 단감빵보다 밀빵이 높은 반면 촉촉함은 단감빵이 높았다. 전반적인 기호도는 단감가루를 10%, 대체한 경우가 가장 높고 과 다음이 5% 대체한 단감빵, 대조구 밀빵 순으로, 대조구 밀빵보다 단감빵의 기호도가 좋다고 평가되었다.

• 한국인구학
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• 제11권2호
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• pp.67-76
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• 1988

The purpose of this study was to find out the factors affecting birth sex ratio which had revealed alarmingly higher in recent years. This study was conducted to get hold of the basic data such as the sex ratio of live births which had been delivered at 5 general hospitals in Taegu from 1982 to 1986. And author chose Dongsan Medical Center from those 5 hospitals for further detailed study, and reviewed 1,286 medical records of mothers who had birth in each February and March from 1984 to 1987. Of these 1,286 deliveries, 30 cases were twin deliveries, which added the total children numbers to 1,316. The findings of this study were as follows: The average of birth sex ratio( 114.5) for 5 years at five general hospitals in Taegu was slightly higher than the traditional birth sex ratio( 102-107) and the highest was 123.4 in 1985. There was no significant difference in birth sex ratio by mother's educational level, her religion nor father's occupation. The birth sex ratio of the cases whose mother was above 35 years old was significantly high(400.0), that of the cases who were born to the mothers who had more than 3rd parity was significantly high(309.5), and that of the cases whose mother had more than two daughters and no son was also significantly high (330.7). The birth sex ratio of the cases who did not have ultrasonogram on their prenatal visits was 87.8. In contrast to this, that of the cases who had ultrasonogram was significantly higher( 135.5). Of the mothers who have more than two daughters and no son' 80.4% (45 cases) had ultrasonogram and their newborn's birth sex ratio was significantly high(542.9). Of the cases who were born to more than 3rd parity mothers, 75.6%(65 cases) of their mothers had ultrasonogram and their sex ratio was significantly high(441.6). It was revealed by this study that the birth sex ratio is changed to significantly high due to sex confirmation of the fetus by ultrasonogram. Thus it is recommended that the value related to having equality of sexes must be ingrained by changing the various social systems and value systems which is now aggrevating the son preference and should provide controlling system which can prohibit the ultrasonogram for sex confirmation only.

• 한국세라믹학회지
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• 제26권5호
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• pp.705-711
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• 1989

The glass-ceramics was prepared with the scoria(CaO-MgO-Al2O3-SiO2 system) of the locally occurring volcanic ejecta containing 10-13w/o of (FeO＋Fe2O3) by melting at 140$0^{\circ}C$ for 4 hours and thermally treated for nucleation and crystallization. The sucrose was added to the scoria to adjust the Fe2+/Fe3+ ratio during the melting process. The addition of 1-2w/o of sucrose showed the glass-ceramics body with the finest particle developed and dispersed over the entire range. It is concluded that the impurity content of iron oxide and titanium oxide play the most-influencial effect on the crystallization. When 1-2w/o of sucrose was added to the scoria, the value of Fe2+/Fe3+ ratio was 0.93-1.32 and showed the best result of crystallization. The nucleation temperature and time were calculated by the measurements of exothermic peak temperatures of DTA for quenched and thermally treated glasses. The nucleation temperature of scoria glass without the addition of sucrose was estimated as 75$0^{\circ}C$, but the addition of sucrose by 2w/o showed the nucleation temperature 6$25^{\circ}C$. The nucleation time was calculated with the same DTA curves. The nucleation times estimated were about 150min. for both of glasses without and with sucrose added. Finally, the activation energies for crystallization were calculated with the DTA data. The calculated activation energies were 143 Kcal/mole for the glass without addition of sucrose and 90Kcal/mole, 87Kcal/mole, 85Kcal/mole and 71Kcal/mole for the glasses of 1w/o, 2w/o, 3w/o and 4w/o addition respectively.

• 한국식생활문화학회지
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• 제20권3호
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• pp.352-359
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• 2005

The red ginseng powder was added to Yackwa dough as ratio to 0%, 2%, 4%, 6% and 8%, respectively to know effect of red ginseng powder on Yackwa quality and preservation. The expansion, color, texture and preference characters were investigated at 0,2 and 4 weeks, respectively. The peroxide and acid value were also measured. The 4% addition increased greatly expansion rate. In color test, L value lowed at addition of red ginseng powder and at long storage period. the b value lowed as the addition was increased, but a value was not affected by the addition of red ginseng powder. In mechanical texture test, addition of red ginseng powder had a tendency to show low cohessivness, springness, gumminess while hardness increased. The springness, brittleness and cohessivness decreased while hardness increased at long storage period. In sensory test, surface color, bitterness and red ginseng flavor were recognized strong by addition of red ginseng powder but oily taste, crispness, softness and overall preference were weak. The surface color and red ginseng flavor were strong at long storage period but sweetness, softness and overall preference decreased, respectively. The peroxide value increased at long storage period and decreased after 6 week. The 2% and 4% addition showed lower peroxide value compared to other treatment. The acid value increased at early storage period, but did not change after 4 weeks.

• 한국조리학회지
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• 제23권7호
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• pp.80-87
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• 2017

This study was conducted to investigate the effective ratio of Sulgidduk to steaming chesnut powder. I measured the sensory and mechanical characteristics, moisture content and color values of Sulgidduk added by different amount 4 of types of steaming chestnut powder; 0% (Control-0 group), 1% (CP-1 group), 2% (CP-2 group), 3% (CP-3 group), 4% (CP-4 group). Moisture content of Sulgidduk with steaming chestnut powder ranged from 38.53% to 46.05%. The L-value and b-value of the color decreased with an increase in steaming chestnut powder; however, a-value of the color decreased with an increase in steaming chestnut powder. As a result of analysis the texture of Sulgidduk steaming chestnut powder, it's hardness, springiness was increased. According to the sensory evaluation, CP3 had the highest values in texture and overall acceptability. Based on the result, it's considered that the most desirable ratio is steaming chestnut powder CP3. The results of the study supported the benefits of steaming chestnut powder supplementation in Sulgidduk in the aspects of taste and functionality. The degree of further increase in Sulgidduk with steaming chestnut powder without causing an adverse quality effect, remain for future study.

• International Journal of Automotive Technology
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• 제5권3호
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• pp.181-188
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• 2004

A cylindrical constant-volume combustion chamber was used to investigate the flow characteristics at the spark electrode gap and the combustion characteristics of an inhomogeneous charge methane-air mixture under several parameters such as stratified pattern, initial charge pressure, ignition time and the excess air ratio of the initial charge mixture. Flow characteristics including mean velocity and turbulence intensity were analyzed by a hot-wire anemometer. The combustion pressure development, measured by a piezo-electric pressure transducer, was used to investigate the effect of initial charge pressure, excess air ratio and ignition times on combustion pressure and combustion duration. It was found that the mean velocity and turbulence intensity had the maximum value around 200-300 ms and then decreased gradually to near-zero value at 3000 ms. For the stratified patterns, the combustion rate under the rich injection (RI) condition was the fastest. Under the initial charge conditions, the second mixture was accompanied by an increase in the combustion rate, and that the higher the mass which is added in the second stage injection, the faster the combustion rate.

• 반도체디스플레이기술학회지
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• 제22권2호
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• pp.35-39
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• 2023

Silicon oxide thin films have been deposited by plasma-enhanced chemical vapor deposition in SiH4 and N2O plasma along the variation of the gas flow ratio. Optical emission spectroscopy was employed to monitor the plasma and ellipsometry was employed to obtain refractive index of the deposited thin film. The atomic ratio of Si, O, and N in the film was obtained using XPS depth profiling. Fourier Transform Infrared Spectroscopy was used to analyze structures of the films. RI decreased with the increase in N2O/SiH4 gas flow ratio. We noticed the increase in the Si-O-Si bond angles as the N2O/SiH4 gas flow ratio increased, according to the analysis of the Si-O-Si stretching peak between 950 and 1,150 cm-1 in the wavenumber. We observed a correlation between the optical emission intensity ratio of (ISi+ISiH)/IO. The OES intensity ratio is also related with the measured refractive index and chemical composition ratio of the deposited thin film. Therefore, we report the added value of OES data analysis from the plasma related to the thin film characteristics in the PECVD process.

• Journal of Advanced Marine Engineering and Technology
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• 제33권5호
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• pp.672-678
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• 2009

Acoustic Emission (AE) technique is a non-destructive testing method and widely used for the early detection of faults in rotating machines in these days, because the sensitivity of AE transducers is higher than normal accelerometers. So it can detect low energy vibration signals. The faults in the rotating machines are generally occurred at bearings and gearboxes which are the principal parts of the machines. It was studied to detect the bearing faults by envelop analysis in several decade years. And the researches showed that AE had a possibility of the application in condition monitoring system(CMS) using the envelope analysis for the rolling bearing. And peak ratio (PR) was developed for expression of the bearing condition in condition monitoring system using AE. Noise level is needed to reduce to take exact PR value because the PR is calculated from total root mean square (RMS) and the harmonics peak levels of the defect frequencies of the bearing. Therefore, in this paper, the discrete wavelet transform (DWT) was added in the envelope analysis to reduce the noise level in the AE signals. And then, the PR was calculated and compared with general envelope analysis result and the result of envelope analysis added the DWT. In the experiment result about inner fault of bearing, defect frequency was difficult to find about only envelop analysis. But it's easy to find defect frequency after wavelet transform. Therefore, Envelop analysis added wavelet transform was useful method for early detection of default in signal process.

• 에너지공학
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• 제15권3호
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• pp.139-145
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• 2006

The purpose of this study is to obtain low-emission and high-efficiency in LPG engine with hydrogen enrichment. The objective of this paper is to clarify the effects of hydrogen enrichment in LPG fuelled engine on exhaust emission, thermal efficiency and performance. The compression ratio of 8 was selected to avoid abnormal combustion. To maintain equal heating value of fuel blend, the amount of LPG was decreased as hydrogen was gradually added. The relative air-fuel ratio was increased from 0.8 to 1.3, and the ignition timing was controlled to be at MBT (minimum spark advance for best torque)