• 한국환경보건학회지
• /
• 제43권6호
• /
• pp.457-466
• /
• 2017

Objectives: This study was carried out to investigate the characteristics of volatile organic compounds (VOCs) emitted from sewerage facilities such as a sanitary sewers, outlets, and catch basins. In addition, the dominant malodorous VOCs among the compounds in this study were studied. Methods: Waste gas samples were collected at 27 points in a sanitary sewer in commercial and residental areas. The concentrations of seven volatile organic compounds, including benzene and toluene, in the samples were analyzed by gas chromatograph mass spectrophotometer (GC/MS). Odor concentrations were estimated using the concentration data of the VOCs and each compound's threshold limit value. Results: As a result, it appeared that the average concentration of total observed data for acetaldehyde was 15.98 ppb and benzene 1.87 ppb, toluene 82.31 ppb, ethyl benzene 63.12 ppb, m+p-xylene 15.66 ppb, oxylene 18.73 ppb, and styrene 4.39 ppb. VOC concentrations in the commercial area were higher than those in the residential area. VOC concentrations of waste gas emitted from sewer lines was also higher than those at the outlet and in the catch basins. It was estimated that the main malodorous VOC among the seven VOCs was acetaldehyde. Conclusions: As there is little data on VOC concentrations inside sewer facilities in Korea, these data will be helpful for estimating impact assessment of VOCs and establishing a counter-plan for the abatement of VOCs from sewer facilities in the future.

• Food Science and Biotechnology
• /
• 제16권2호
• /
• pp.290-293
• /
• 2007

Cassumunar ginger (Zingiber montanum Roxb.) was grown in the experimental field at the Department of Horticulture, Kasetsart University, Thailand. The antioxidant activity and volatile oil content of rhizomes of varying age were measured. Antioxidant activity as determined using the DPPH (diphenyl-2-picrylhydrazyl) method differed significantly between samples of different ages. Antioxidant activity and rhizome age were positively correlated, with 22-month old rhizomes showing the highest radical scavenging activity (79.19%). Volatile oil was obtained by steam distillation of fresh rhizomes. The extraction yield of volatile oil was highest in l6-month old rhizomes (13.02 mL/kg). GC-FID data indicated the presence of three major compounds, sabinene, terpinen-4-ol and (E)-1-(3',4'-dimethylphenyl) butadiene (DMPBD), however none of the major components were correlated with the age of rhizome.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제5권4호
• /
• pp.262-269
• /
• 2005

Semiconductor scientists and engineers ideally desire the faster but the cheaper non-volatile memory devices. In practice, no single device satisfies this desire because a faster device is expensive and a cheaper is slow. Therefore, in this paper, we use heterogeneous non-volatile memories and construct an efficient hierarchy for them. First, a small RAM device (e.g., MRAM, FRAM, and PRAM) is used as a write buffer of flash memory devices. Since the buffer is faster and does not have an erase operation, write can be done quickly in the buffer, making the write latency short. Also, if a write is requested to a data stored in the buffer, the write is directly processed in the buffer, reducing one write operation to flash storages. Second, we use many types of flash memories (e.g., SLC and MLC flash memories) in order to reduce the overall storage cost. Specifically, write requests are classified into two types, hot and cold, where hot data is vulnerable to be modified in the near future. Only hot data is stored in the faster SLC flash, while the cold is kept in slower MLC flash or NOR flash. The evaluation results show that the proposed hierarchy is effective at improving the access time of flash memory storages in a cost-effective manner thanks to the locality in memory accesses.

• 한국콘텐츠학회논문지
• /
• 제21권7호
• /
• pp.157-163
• /
• 2021

파일 시스템에서 하나의 쓰기 연산은 여러 데이터를 수정할 수 있지만, 이러한 파일 시스템의 변경들은 원자적으로 디스크에 써지지 않는다. 따라서 파일 시스템의 일관성을 위해 기존의 저널링 기법은 시스템 성능을 저하시키는 대신 충돌 일관성을 보장한다. 비휘발성 메모리를 저널 공간으로 사용하면 비휘발성 메모리의 낮은 지연 시간과 바이트 수준 접근성으로 성능 저하를 완화시킬 수 있다고 알려졌다. 그러나 비휘발성 메모리를 고려한 저널링 기법 중에서 확장성을 제공하는 것은 없다. 본 논문에서는 확장적 저널링을 위해 비휘발성 메모리상의 저널 공간을 여러 영역으로 분할하여 한 영역에 집중된 연산을 분산시킨다. 또한, 저널 영역별로 입출력 쓰레드를 두어 저장 장치에 데이터 쓰기 연산을 가속화한다. 제안된 기법을 JFS에 적용하여 고성능 저장장치를 탑재한 멀티코어 서버에서 이를 평가한다. 평가 결과는 제안된 기법이 기존의 NVM 기반 저널링 파일 시스템의 기법보다 성능이 우수함을 보여준다.

• 한국식품과학회지
• /
• 제40권3호
• /
• pp.271-276
• /
• 2008

본 연구에서는 공장산 된장과 전통 된장 제품을 이용하여 가열조건(상온, $50^{\circ}C$, $100^{\circ}C$)을 달리한 시료의 휘발성 향기성분을 HS-SPME법에 의해 추출한 후, GC-MSD를 이용하여 분석동정하였고 이들 성분의 정량분석도 실시하였다. 정성된 화합물은 총51개의 향기성분이 확인되었고 동정된 성분을 화학적 특성에 따라 분류하면 18 esters, 3 alcohols, 6 acids, 8 pyrazines, 5 volatile phenols, 1 ketones, 6 aldehydes와 4개의 기타성분이 동정되었다. 에스터 성분과 산 성분이 동정된 화합물 중 두 개 시료에서 모두 가장 높은 농도를 차지하였다. 전통된장 시료는 가열 온도가 증가함에 따라 산, 피라진류의 증가가 두드러졌고, 공장산 제품의 경우 에스터, 알데히드류 및 maltol과 acetyl pyrrole과 같은 일부 마이얄반응 부산물이 크게 증가하는 것으로 나타났다. 향후, 관능검사 및 GC-Olfactometry 분석을 통한 전통 및 공장산 제품의 관능특성과 주요 휘발성 향기성분간의 상관관계분석이 필요하리라 판단되고 이를 통해 다양한 관능특성의 맞춤형 제품 개발에 기초자료로 활용할 수 있으리라 여겨진다.

• 한국컴퓨터정보학회논문지
• /
• 제21권5호
• /
• pp.167-175
• /
• 2016

The volatile component analysis of 82 commercialized liquors(44 samples of single malt whisky, 20 samples of blended whisky and 18 samples of brandy) was carried out by gas chromatography after liquid-liquid extraction with dichloromethane. Pattern recognition techniques such as principle component analysis(PCA), cluster analysis(CA), linear discriminant analysis(LDA) and partial least square discriminant analysis(PLSDA) were applied for the discrimination of different liquor categories. Classification rules were validated by considering sensitivity and specificity of each class. Both techniques, LDA and PLSDA, gave 100% sensitivity and specificity for all of the categories. These results suggested that the common characteristics and identities as typification of whiskies and brandys was founded by using multivariate data analysis method.

• 한국산업보건학회지
• /
• 제16권4호
• /
• pp.413-427
• /
• 2006

It is necessary to study and develop guidelines for providing comfort and health indoor air quality for office workers since air-tight envelope system of current office building may cause poor indoor air quality. The purpose of this study is to propose guideline for volatile organic compounds in office base on the field study, human health risk assessment and cost-benefit analysis. The field study was conducted to survey the concentrations of volatile organic compounds in indoor air of 69 offices from June to September, 2005 in Seoul and Gyeonggi-do. The rate of excess to guideline of volatile organic compounds in indoor air of new apartment on the Ministry of Environment in Korea(MOE) was surveyed 37.6% for benzene, 6.8% for toluene, and 1.5% for ethylbenzene. As the result of human health risk assessment, mean cancer risk did not exceed 10-6 which is guideline of US.EPA. Also, total hazard index did not exceed 1 which is guideline of US.EPA. Through the cost-benefit analysis of angle on the social-economics to verify the necessary to establish the standards of volatile organic compounds for improvement and development of indoor air quality in office, the present value of benefit was higher than the present value of cost. With the above considerations in mind, it is suggested that the field study for indoor air quality in offices should be expanded and human health risk assessment and cost-benefit analysis be performed th offer scientific data for decision-making of policy for improvement and management of indoor air quality in office.

• 한국식품과학회지
• /
• 제47권5호
• /
• pp.567-573
• /
• 2015

일본 증류식 소주인 본격소주 9종을 수거하여 시료의 휘발성 향기성분을 헤드스페이스-고체상미량추출법에 의해 추출한 후, 가스크로마토그래피-질량분석기를 이용하여 분석하였다. 총 76개의 성분이 동정되었고, 화학적 특성에 따라 분류하면 에스터 48종, 알코올 13종, 기타 15종의 성분이 동정되었다. 에스터와 알코올이 주요한 성분으로 분석되었으며 아세트산아이소아밀, 폼산아이소아밀, 헥산산에틸, 옥탄산에틸, 데카노산에틸, 아이소아밀알코올, 2-페닐에탄올이 주요 성분으로 나타났다. 주성분 분석 결과 제조원료에 따라 주성분1 선상에서 대맥국 원료 본격소주의 향기패턴이 큰 차이를 보이는 것으로 나타났으며 쌀과 보리 원료에 따른 향기패턴의 차이는 크게 나타나지 않았다. 본 연구의 일본 본격소주 휘발성 향기성분 분석 결과와 국내산 증류식 소주의 주요 향기성분 분석 결과를 비교분석하면 향후 국내산 증류식 소주의 품질관리에 주요한 향기성분 파악이 가능하고 이를 통해 다양한 원재료와 제조방법에 따른 증류식 소주 제품 개발이 가능하리라 여겨진다.

• 한국멀티미디어학회논문지
• /
• 제19권7호
• /
• pp.1179-1187
• /
• 2016

Through the rapid development of latest hardware technology, high performance as well as miniaturized size is the essentials of embedded system to meet various requirements from the society. It raises possibilities of genuine realization of IoT environment whose size and battery must be considered. However, the limitation of battery persistency and capacity restricts the long battery life time for guaranteeing real-time system. To maximize battery life time, low power technology which lowers the power consumption should be highly required. Previous researches mostly highlighted improving one single type of memory to increase ones efficiency. In this paper, reversely, considering multiple memories to optimize whole memory system is the following step for the efficient low power embedded system. Regarding to that fact, this paper suggests the study of volatile memory, whose capacity is relatively smaller but much low-powered, and non-volatile memory, which do not consume any standby power to keep data, to maximize the efficiency of the system. By executing function in specific memories, non-volatile and volatile memory, the quantitative analysis of power consumption is progressed. In spite of the opportunity cost of all of theses extra works to locate function in volatile memory, higher efficiencies of both power and energy are clearly identified compared to operating single non-volatile memory.

• Food Science and Biotechnology
• /
• 제16권3호
• /
• pp.374-380
• /
• 2007

Chemical and sensory profiles of 5 Korean commercial rice wines (yakju) were developed using descriptive, physicochemical, and volatile analyses. Color, 6 aroma, and 5 taste attributes of these rice wines were evaluated by a panel of 13 judges. Sample wines were analyzed for titratable acidity, ethanol content, pH, Hunter colorimeter value, organic acids, and free sugars. Volatile analysis of the samples revealed the presence of 2 acids, 7 alcohols, 19 esters, and 5 miscellaneous compounds. Based on principal component analysis of the descriptive data, rice wines were primarily separated along the first principal component, which accounted for 57% of the total variance between the rice wines with high intensities of 'color' and 'sweet aroma' versus 'ginseng' aroma.