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        검색결과 1,376

        222.
        2016.11 구독 인증기관·개인회원 무료
        PVDF Membrane has been used as material for the UF membrane through in-situ interfacial polymerization (IP) because of it’s outstanding properties such as high chemical resistance, thermal stability, and mechanical strength. In this study, surface morphology change of PVDF membrane was researched depending on evaporation time. 13% PVDF 6020 was used for casting and the evaporation time period was from 5s to 600s. The surface morphology of the membrane was investigated by scanning electron microscopy (SEM) and filtration was conducted in the cross flow method to evaluate the a performance of UF membrane. As a result, average pore size was increased with longer evaporation times which caused the decrease of rejection.
        227.
        2016.10 구독 인증기관·개인회원 무료
        The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is an economically damaging pest that feeds on most thin-skinned fruits. In this study, we sequenced portions of the mitochondrial (mt) COI and ND4 genes from a total of 195 individuals collected mainly from Korea. A total of 139 haplotypes were obtained from the concatenated COI and ND4 sequences. A dataset combining GenBank sequences with our own data identified a total of 94 worldwide COI haplotypes with a maximum sequence divergence of 5.433% (32 bp). A rough estimate of genetic diversity in each country showed higher diversity in ancestral distributional ranges, but the invasion over Asian countries seems to have been substantial because haplotype diversity was only 2.35-3.97-fold lower in the USA, Canada, and Italy than that in the populations ancestral ranges.
        228.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was an attempt to analyze the basic analytical characteristics of octanal and nonanal compounds by TD and GC/FID system. The basic analysis (linearity, precision, MDL: method detection limit) showed similar results for VOCs in terms of QA/QC results with the same analysis system. Also, the results are sufficiently satisfy the QA/QC of the Korean odor analysis standard method. When using a polyester aluminum bag, the amount of loss was found to be about -2% to 7%. Adjusting the relative humidity and loss trend with the passage of time, the loss amount is found to be only a trace amount. With the exception of the styrene compound, all volatile organic compounds have a tendency to decrease slightly. Similar results were shown from Octanal and Nonanal. As a result, Octanal and Nonanal compound’s adsorption amount by the polyester aluminum bag was a quite small. The relative humidity and other compounds appear to be significantly unaffected by Octanal and Nonanal.
        4,500원
        229.
        2016.09 구독 인증기관 무료, 개인회원 유료
        잉크젯 프린트물의 광택을 상용광택기를 이용하여 손쉽게 측정하여 이미지의 질을 평가하는데 사용 하였다. 출력된 이미지에 영향을 줄 수 있는 조건들을 부여하여 인위적으로 변형시킨 후 광택을 측정하여 그 변화를 살펴보았다. C, M, Y, BK 잉크의 색상에 따라 광택값에 차이가 있었지만 이미지 변형은 열을 동반한 다림질, 습기, 높은 온도에서의 건조, 초산과 같은 화학약품 등의 요인들에 의하여 일어나며 이미지의 광택변 화량을 살펴보아 각각의 인자가 얼마만큼 광택을 변화시키는가를 알아보았다. 높은 온도나 열에 의한 급속한 변화가 광택값을 변화시키는 가장 큰 요인으로 확인되었으며 이미지를 포함한 문서나 필름등의 보관시에 가 장 먼저 고려되어야 할 조건임을 알 수 있었다.
        4,000원
        230.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, an outrigger damper system has been proposed to reduce dynamic responses of tall buildings. However, a study on outrigger damper system is still in its early stages. In this study, time history analysis was performed to investigate the dynamic response control performance of outrigger damper. To do this, a actual scale 3-dimensional tall building model with outrigger damper system has been developed. El Centro earthquake was applied as an earthquake excitation. The control performance of the outrigger damper system was evaluated by varying stiffness and damping values. Analysis results, on the top floor displacement response to the earthquake load, was greatly effected by damping value. And acceleration response greatly was effected by stiffness value of damper system. Therefore, it is necessary to select that proper stiffness and damping values of the outrigger damper system.
        4,000원
        231.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigates on the tuning stainless steel(STS630) to understand for groove cutting characteristics. For this purpose, we observed the cutting force according to feed rate and cutting speed variation and performed the computational analysis due to groove cutting depth. In groove cutting of stainless steel, there were principal force, feed force and radial force by arranging the highest cutting force in order. In case of wall thicknesses of 0.3mm and 0.5mm at groove cutting, principal force increases according to the increase of feed rate but it is not related to cutting speed. We found the unstable region of cutting force that is caused to the friction resistance of cutting tool and elastic deformation of groove wall. In computational analysis, we confirmed that the more feed rate increases, the more strain increases around the tooth root.
        4,000원
        232.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Control degree and property changes of dissolved organic matter (DOM) were conducted by coagulation of chemical treatment for 2 sewage treatment plants with different technical methods. As the result, SUVA value of the second treated water (supernatant of the second settling pond after biological treatment) was increased and DOC was reduced in comparison with supplied raw water. And, SUVA value and DOC were reduced by coagulation after coagulation treatment of the second treated water. Properties of dissolved organic matter for 2 sewage treatment plants's DOC were divided. As the result, there was lots of hydrophilic component with hydrophilicity in case of plant A. In case of the second treated water, Plant A showed fulvic acid with little molecular weight was reduced among the hydrophobic component with hydrophobicity, but numic acide with lots of molecular weight was increased. However, in case of plant B, both fulvic acid with little molecular weight and humic acid with lots of molecular weight were increased among the hydrophobic components with hydrophilicity. Before the operation of phosphorus facility, properties of dissolved organic matter after biodegradation with effluent water showed hydrophilic components were reduced and hydrophobic components were increased. However, after coagulation treatment of the second treated water, hydrophilic components and hydrophobic components were outstandingly decreased or increased. During the biodegradation after coagulation treatment, hydrophilic components were significantly decreased and hydrophobic components were increased.
        4,000원
        233.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sesquiterpene lactones (SLs) are a group of over 500 compounds, characteristic of the Asteraceae. They are interesting from the chemical and chemotaxonomic point of view, and show antitumour, anti-leukaemic, anti-cardiovascular disease, reduction of inflammation, and anti-microbial activities. The SLs, free lactucin and lactucopicrin, content in 572 accessions of lettuce (Lactuca sp.) germplasm introduced from 30 countries were quantified using high-performance liquid chromatography. Variation range of free lactucin content exhibited trace ~ 235.3 μg from 1g of dried leaves and average was 41.2 ± 1.2 μg (Avr ± SE), variation range 55.0 ~ 3,041.0 μg and average 526.9 ± 17.5 μg in free lactucopicrin content, and variation range 66.3 ~ 3,188.5 μg and average 568.1 ± 18.1 μg in total free SLs content. Lactucopicrin occupied 92.7% of the total SLs content. Among the varietal types, crisphead type exhibited the highest average total free SLs content, next is leaf lettuce, and butterhead type lettuce exhibited the lowest that of content. German accessions exhibited the lowest average total free SLs content, Korean accessions exhibited the highest, and European origin accessions exhibited lower that of content. Red leaf color accessions having higher SLs content than that of green color. Seven accessions having more than 2,000 μg·g-1 dwt of total free SLs content and five accessions having less than 100 μg·g- 1dwt that of content. These accessions can be used as low SLs content cultivar breeding or high SLs content cultivar breeding sources as well as research materials for medical treatment such as, anti-tumour, anti-leukaemic, and antimicrobial activities, etc.
        4,000원
        234.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There can be included a variety of uncertainties in all measurement results whether we can perceive or not on the causes. These uncertainties may end up in lowering the reliability of measurement results and also deteriorate the level of quality. For the purpose, we tried to combine the strengths of measurement uncertainty and measurement system analysis together to present a practical flowchart so as to verify those potential variation factors in general measurement processes. As a case study, we did an experiment and gathered data on the length between two holes of an engine cylinder head which is a core part for vehicles with a coordinate measuring machine and estimated nine uncertainty factors of it. Consequently, it was identified that the four primary factors among the nine which were related to the measurement standard, random errors or spread of the repeat measurements, differences between the coefficients of thermal expansion and the environment especially had been the influence around the laboratory. Since it is impossible to analyze the equipment and appraisal variations respectively through the only measurement uncertainty, we have used the measurement system analysis following the flowchart. Showing the result of being just about 0.5 % lower for the appraisal variation, and the equipment variation occupied about 7% for the total Gage R&R. Through this research, we have come to a conclusion that much more detail analysis on variation factors can be possible to be identified in measurement processes by using the developed flowchart which is composed of measurement uncertainty and measurement system analysis. Therefore, we expect engineers who are involved in quality and measurements to utilize this developed method.
        4,000원
        235.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rail wear in a curved track costs significant amount of maintenance efforts every year. The rail wear is affected by such parameters as train speed, curve radius, and insufficient cant. However, while the effect of train speed and curve radius to the rail wear is relatively well-known, the effect of the insufficient cant has not analytically researched sufficiently. In this paper, the effect of the insufficient cant on rail wear is studied using a multibody dynamics program, the Vi-Rail. The multibody analysis is performed using an EMU train model being operated in the urban railway. The hard track is utilized in the analysis. To identify the relationship between rail wear and insufficient cant. the wear analysis is conducted for various train speeds and curve radius based on the Archard model built in the Vi-Rail program. The analysis result reveals that, as the insufficient cant increases, the vertical and horizontal wear of the outer rail increases, but the wear of the inner rail does not show distinct trend.
        4,000원
        236.
        2016.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With the results of observations in 2013 and 2014 including ocean buoys, in-situ investigations and wind data, we examined the spatio-temporal variation of cold water masses along the eastern coast of Korea. Usually, a cold water mass first appears along the northern part of the eastern coast from May to July, and then along the southern part of the eastern coast from late June to mid-August. Cold water masses appear 3~5 times a year and remain for 5~20 days in the southwestern part of the East Sea. A distinctive cold water mass appeared usually in mid-July in this area, the surface temperature of which was below 10℃ in some cases. During the appearance of a cold water mass in the southwestern part of the East Sea, the horizontal temperature gradient was large at the surface and a significant low water temperature below 8℃ appeared at the bottom level. This appearance of cold water masses clearly corresponded to southwesterly winds, which generated coastal upwelling.
        4,000원
        238.
        2016.05 구독 인증기관 무료, 개인회원 유료
        Infrared thermography provides the colorful images of concerning area where local changes of surface temperature occurs and can be used to measure the fine temperature of human body. Unlike the radiography technique, it is determined by the presence or absence of existing anatomical principles capable of quantitative evaluation and visible to the physiological and functional state of the human body. In this paper, it was studied the characteristics of dynamic motion conditions in the hands due to physiological changes of temperature distribution. The results showed that the difference between the change in temperature characteristics for the left and right hand.
        3,000원
        239.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        울릉 난수성 소용돌이의 수온 변동을 보기 위하여, 동해중부해역(동해항-독도의 지선)에서 2013년 7월부터 2015년 7월까지 소모성 수온기록계(XBT)와 국립수산과학원의 정선 해양 관측 자료를 이용하여 살펴보았다. 울릉 난수성 소용돌이의 완전한 형태를 볼 수 없었을지라도, 조사 단면은 울릉 난수성 소용돌이의 특징을 잘 나타내었다. 그 결과, 수온의 변동계수는 평균 수온이 3~4℃의 범위를 가지는 250 m 깊이에서 가장 크게 나타났다. 250 m 층의 수온 변동계수의 수평적 분포는 울릉도와 한국 동해안 사이의 해역에서 가장 컸으며, 이는 울릉 난수성 소용돌이의 핵이 아닌 주변부 해역이었다. 울릉 난수성 소용돌이는 한국 동해 연안에서 남북 혹은 동서로 움직였다, 울릉 난수성 소용돌이는 주로 울릉도 남서 해역에 존재하였으며, 남북 방향으로의 이동성이 동서 방향으로의 이동성보다 크게 나타났다. 250 m 깊이에서 수온의 변동계수가 크게 나타난 것은 울릉 난수성 소용돌이의 하층부에 있는 동해중층수와의 상호 작용에 의한 것으로 보인다. 이것은 울릉 난수성 소용돌이의 하부 깊이에서 울릉 난수성 소용돌이 주변부와 동해중층수와의 상호 작용이 활발하게 발생하고 있음을 시사하고 있다.
        4,000원
        240.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cho Yong‐joon・Ha Ji‐hee. 2016. “On the sociolinguistic variation of Korean mirative markers ‘‐kuna’, ‘‐ney’ and ‘‐ta’”. The Sociolinguistic Journal of Korea 24(1). 241~269. The purpose of this paper is to investigate the sociolingustic variation of Korean mirative markers ‐kwuna, -ney and ‐ta, through an experimental method. A 7‐point Likert scale task was adopted for this purpose. The participant’s age was the significant social factor of the observed linguistic variation, but gender does not play any significant role. Particularly, the elderly generation prefers ‐kwuna for a mirative marker, but this tendency declines for young generation. ‐ta seldom functions as a mirative marker for elderly generation, but it gets an independent status as the mirative marker for young generation. The negative semantico‐pragmatic properties of ‐kwuna affects this change.
        6,900원