• 한국정보과학회논문지:정보통신
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• 제31권1호
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• pp.101-111
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• 2004

기존 유선 인터넷과 달리 무선 인터넷은 낮은 대역폭, 빈번하게 접속이 끊기는 현상, 단말기내의 낮은 컴퓨팅 파워 및 작은 화면, 사용자의 이동성 등의 특성에 따른 많은 제약점들을 갖고 있다. 또한 무선 인터넷 서버는 급증하는 사용자에 따른 대용량 트래픽을 처리할 수 있도록 확장성이 있어야 한다. 이에 위의 문제를 캐싱(Caching)과 압축(Transcoding, Distillation)으로 해결하는 방법으로 무선 프록시서버를 사용한다. TranSend는 클러스터링 기반의 무선 프록시 서버로 제안된 것이나 시스템적인(Systematic) 방법으로 확장성을 보장하지 못하는 단점을 가진다. 이에 본 논문에서는 시스템적인 방법으로 확장성을 보장하는 클러스터링 기반의 무선 인터넷 프록시 서버를 제안한다. 16대의 컴퓨터를 사용하여 실험을 수행하였고 실험 결과 TranSend 시스템에 비해 32.17%의 성능 향상을 보였다.

• Journal of Advanced Marine Engineering and Technology
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• 제39권3호
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• pp.238-242
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• 2015

다중 효용 해수 담수화 설비에 적용되는 증기이젝터 진공장치에 대한 수치해석적 연구를 수행하였다. 본 연구의 목적은 해수 담수화 과정을 위한 증기이젝터 진공장치의 성능특성에 대한 수치적 검토를 수행하는 데에 있다. 증기이젝터 내부의 유동특성을 보다 잘 파악하고 최적의 설계를 도모하기 위하여, 노즐 사이즈 및 디퓨저 축소각의 변화와 같은 설계변수의 변화가 증기이젝터의 성능에 미치는 영향에 대해서도 논의하였다. 해석결과는 실험결과와 전반적으로 잘 일치함을 알 수 있으며, 목부에서의 shock train 현상도 잘 재현하고 있음을 알 수 있다.

• 한국산업보건학회지
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• 제7권2호
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• pp.171-180
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• 1997

The objectives of this study were both 10 discuss the sampling method for airborne metalworking fluids(MWF)' mist and 10 suggest measures to minimize worker's exposure to carcinogen contained in metalworking fluids. In order to measure airborne MWF mist, it seems to be appropriate to use NIOSH Method #0500(filler weight) rather than NIOSH Method # 5026(analysis by FTIR). Because MWF mist on PVC filter evaporated and migrated during sampling, worker's exposure to MWF could be underestimated. So, when evaluating worker's exposure to MWF mist, other environmental conditions also must be considered. Enclosure and local exhaust ventilation system seems to he the most effective measure and must be constructed with process facility. In order to control worker exposure to carcinogens contained in MWF, distillation type and condition for crude oil, PAH concentration in MWF, and viscosity index of MWF must legally be described.

• 한국식생활문화학회지
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• 제12권3호
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• pp.265-274
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• 1997

This study was conducted in ordor to find the most suitable conditions for producing the Doenjang with optimal odor compound contents. Three sample groups with the different preparing methods -Doenjang that has not gone through the soy sauce separation process (Doenjang A), Doenjang that has gone through the soy sauce separation process; Meju-20% salt water ratio of 1 : 4 (Doenjang B), and that with the ratio of 1.3 : 4 (Doenjang C)- were tested during different ripening periods. Odor compound contents were analyzed through Solvent Extraction Method and Simultaneous Steam Distillation Extraction (SDE). The number of odor compounds was greatest in Doenjang A and during the mid to late stage in each groups. In the sensory evaluation of Doenjang odors, Doenjang A received the highest scores in the categories of overall preferences, while Doenjang C got the lowest scores. Individual odor didn't vary significantly during ripening periods, but the overall odor and taste preference was highest in the samples ripened for 75 to 120 days. Stepwise multiple regression analysis of major odor compounds of Doenjang revealed that benzeneacetaldehyde is the major explanatory variable for offensive odor. Benzeneethanol, 3-methylthio-propanal and 4-methyl-phenol are the explanatory variables for salty odor, nutty odor and rancid odor, respectively. Odor compounds that contribute to the overall odor preference varied from the compounds that affect the taste preference.

• 한국응용과학기술학회지
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• 제25권4호
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• pp.495-502
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• 2008

To investigate the synergy effect on the pyrolysis of mixture of polyethylene(PE) and polystyrene(PS), the pyrolysis of PE, PS and the mixture of PE-PS was carried out in a batch reactor at the atmospheric pressure and $450^{\circ}C$. The pyrolysis time was from 20 to 80 mins. The liquid products formed during pyrolysis were classified into gas, gasoline, kerosene, gas oil and heavy oil according to the distillation temperatures based on the petroleum product quality standard of Korea Institute of Petroleum Quality. The analysis of the product oils by GC/MS showed that the new components produced by mixing were not detected. The synergy effect according to mixing of PE and PS did not also appear. The conversion and yield of mixtures were in proportion to the mixing ratio of sample.

• 한국식품조리과학회지
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• 제28권6호
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• pp.675-693
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• 2012

Zubangmoon is Korean cookbooks which was published the ends of 1600s. There were classified 95 kinds of meals, side dishes and rice wine ; 2 kinds of noodles, 4 kinds of soups, 4 kinds of steamed dishes, 1 kind of jeok, 3 kinds of Neureumi, 1 kind of Jeon, 2 kinds of sukhoe, 1 kind of Sundae Pyeonyuk Suran Chae Jaban respectively, 9 kinds of Kimchi & Jangajji, 3 kinds of Jeotgal, 4 kinds of rice cakes, 5 kinds of Yumilgwa, 3 kinds of Yugwa, 2 kinds of beverage, 28 kinds of rice wine, 12 kinds of seasonings, 1 kind of sugar group, 2 kinds of other and 4 kinds of storage method. Foods and recipes of Zubangmoon was similar to Yorok and Eumsikdimibang. But rice wine methods of Zubangmoon were not more than those of Yorok and Eumsikdimibang. Also, distillation method of rice wine was introduced in Zubangmoon and Eumsikdimibang. From this investigation of food and rice wine in Zubangmoon, we expect to develop useful recipes and to advance the Korean food culture.

• 한국식품조리과학회지
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• 제26권6호
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• pp.840-847
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• 2010

In this study, we identified the volatile compounds of Artemisia princeps Pampan. cv. ssajuari (ssajuarissuk) essential oils and analyzed changes in the contents of volatile compounds under four different storage conditions, such as exposure to air at $20^{\circ}C$ and $40^{\circ}C$. Sixty-five volatile compounds consisting of 6 monoterpene hydrocarbons, 23 oxygenated monoterpenes, 16 sesquiterpene hydrocarbons, 6 oxygenated sesquiterpenes, 1 diterpene, 6 benzene derivatives, and 7 non-isoprenoid compounds were identified on the basis of their mass spectra characteristics and retention indices from original ssajuarissuk essential oils. Identified compounds constituted 90.56% of the total peak area. Borneol (10.29%) was the most abundant compound in the original ssajuarissuk essential oils, followed by 1,8-cineole (9.06%), viridiflorol (8.99%), spathulenol (8.73%), $\alpha$-thujone (5.28%), and camphor (4.39%). After six months storage at $40^{\circ}C$ with the cap opened for 3 min everyday, the total amount of volatile compounds in essential oil as determined by the percentage peak area decreased by 84.93%. The total levels of cis-sabinene hydrate, camphor, 4-terpineol, humulene oxide, $\beta$-caryophyllene oxide, and caryophyllene alcohol increased significantly. For ssajuarissuk essential oils stored under experimental conditions, changes in the contents of volatile compounds in essential oils were accelerated by temperature and contact with the atmosphere.

• 한국식생활문화학회지
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• 제30권6호
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• pp.766-772
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• 2015

This research was conducted to investigate the effect of essential oil (EO) from Artemisia Princeps Pampanini on quality of tomato during storage. EO was extracted by steam distillation and diluted by 1 and 2%. Total phenolic contents and antioxidative activities of EO were analyzed. Tomato was packaged corrugated box covered with polypropylene (PP) film containing EO (1 and 2%) and then stored at room temperature for 10 days. During storage, appearance, weight loss rate, soluble solid contents, pH and a (redness) value were measured for tomato. Total phenolic contents of EO increased in a dose-dependence. The DPPH and ABTS radical scavenging activities also showed a concentration-dependent increase. The weight loss rate was lowest using the film packaged in 1% EO. During the storage period, soluble solid contents and pH increased in all treatments. The a value increased regardless of EO concentration in films. Especially, tomato packaged with EO film showed a lower a value than non EO-packaged ones. This result suggests that application of EO to film is effective for tomato quality preservation.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3887-3896
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• 2013

본 연구의 목적은 쌀을 원료로 하여 증류주 제조시 쌀 특성에 적합한 최적의 증류주 효모를 선발하는데 있다. 사용된 5종류의 효모는 전반적으로 정상적인 발효패턴을 보였으나 송천효모(Y1)와 증류주 효모(Y5)가 다른 효모에 비해 우수한 발효력을 보였다. 또한 발효후 술덧을 분석한 결과 고급알코올은 증류주 효모(Y4, Y5)에서, 에스터는 송천효모(Y1)와 증류주효모(Y4, Y5)에서 유의적으로 높게 검출된 반면, 유기산 함량은 증류주 효모(Y3, Y4, Y5)에서 유의적으로 높게 나타났다. 발효술덧을 동증류기를 이용한 상압증류한 증류주 분석 결과 송천효모(Y1)와 증류주 효모(Y5)가 최종 알코올 농도가 높아 제조수율에 유리한 것으로 판단되며, 고급알코올과 에스터 등 향기 성분은 발효술덧 분석 결과와 같이 고급알코올은 증류주 효모(Y4, Y5)에서, 에스터는 송천효모(Y1)와 증류주 효모(Y4, Y5)에서 유의적으로 높게 나타나 발효술덧의 향기 패턴이 증류주에 대부분 전이되는 것으로 판단된다. 효모별 발효특성과 발효술덧 및 증류주의 물리화학적 특성, 관능평가를 종합한 결과 증류주 효모인 siha aktivehefe 6 brennereihefe(Y5)가 쌀을 이용한 증류주 품질 최적화에 가장 적합한 효모로 선발되었다.

• 한국식품영양과학회지
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• 제36권12호
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• pp.1637-1642
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• 2007

생마늘과 열처리에 따른 마늘의 향기 특성과 향기추출물의 항산화활성을 확인하고자 국내산 한지형 마늘 3종(단양, 서산, 의성마늘)과 난지형 마늘 3종(남해, 남도, 대서마늘), 중국산 마늘에 대하여 simultaneous distillation and extraction(SDE) 방법으로 향기 성분을 추출하여 GC/MS로 동정하고 항산화활성을 측정하였다. 생마늘의 주요 향기성분은 allyl methyl sulfide, methyl-2-propenyl disulfide, diallyl disulfide, 2-ethylidene-1,3-dithiane, methyl-2-propenyl trisulfide, di-2-propenyl trisulfide 및 2-vinyl- 4H-1,3-dithiin 등으로 나타났다. 항산화활성이 우수한 것으로 알려진 diallyl disulfide, methyl-2-propenyl trisulfide 및 di-2-propenyl trisulfide 등은 중국산 마늘보다 한지형 마늘이 많이 함유하고 있었다. 향기성분은 열처리시 2-propanone, allyl mercaptan, methyl formic acid, 2-methyl butanal 2-methyl thiophene, methyl pyrazine, 2,2-dimethyl-1,3-dithiane 및 2-propenyl propyl disulfide 등이 새롭게 생성되었으며, allyl methyl sulfide, allyl alcohol 및 allyl sulfide 등의 분자량이 작은 화합물의 함량이 증가하였다. 산지별 생마늘의 향기 추출물에 대한 항산화활성은 농도 의존적으로 증가하였으며, 단양, 남해 및 중국산은 각각 20.07, 34.62 및 9.71%의 항산화활성을 나타내었고, 열처리 후에는 각각 79.90, 93.59 및 77.26%로 증가하였다.