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        검색결과 450

        181.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the densification behavior of rhenium alloys including W-25 wt.%Re and Re-2W-1Ta (pure Re) during sintering. The dilatometry experiments were carried out to obtain the in-situ shrinkage in H2 atmo-sphere. The measured data was analyzed through shrinkage, strain rate and relative density, and then symmetricallytreated to construct the linearized form of master sintering curve (MSC) and MSC as a well-known and straightforwardapproach to describe the densification behavior during sintering. The densification behaviors for each material were ana-lyzed in many respects including apparent activation energy, densification parameter, and densification ratio. MSC witha minimal set of preliminary experiments can make the densification behavior to be characterized and predicted as wellas provide guideline to sinter cycle design. Considering the results of linearized form and MSC, it was confirmed thatthe W-25 wt.%Re compared to Pure Re is more easily densified at the relatively low temperature.
        4,000원
        182.
        2013.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We develop a radio receiver system operating at λ ~ 1.3 mm for the 6 m telescope of Seoul Radio Astronomy Observatory. It consists of a dual polarization receiver, a couple of IF processing units, two FFT spectrometers, and associated software. By adopting sideband-separating superconductor mixers with image band terminated to waveguide load at 4.2 K, we achieve TRX ≤ 100 K and Tsys less than 150 K at best weather condition over 210-250 GHz frequency range. The intermediate frequency signal of 3.5-4.5 GHz is down converted to 0-1 GHz and fed into the FFT spectrometers. The spectrometer covers 1 GHz bandwidth with a spectral resolution of 61 KHz. Test observations are conducted toward several radio sources to evaluate the performance of the system. Aperture and beam efficiencies measured by observing planets are found to be typically 44  59% and 47  61%, respectively over the RF band, which are consistent with those measured at 3 mm band previously.
        4,000원
        183.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rotaviruses are double-stranded RNA viruses of the family Reoviridae, a highly diverse family of pathogens of humans and animals. In this study, we identified the lapine rotavirus from diarrheic feces of rabbits by polymerase chain reaction. In order to determine the genetic characteristics of the Korean strain, the sequences of the VP4, VP7, and NSP4 genes were determined and compared with those of reference sequences. Results of sequence and phylogenetic analyses showed that our strain was a G3P [3] rotavirus carrying the group C gene encoding NSP 4 proteins. This is the first report of an outbreak and molecular characterization of lapine rotavirus in Korea.
        3,000원
        184.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Previously, we demonstrated the presence of a second copy of LPS myristoyl transferase in enterohemorrhagic Escherichia coli O157:H7, an important zoonotic diarrheagenic food-borne pathogen; the pO157-encoded ecf (an eae-conserved fragment) and the chromosomally-encoded lpxM (also referred to as msbM) genes. Although both genes share the same function as an LPS myristoyl transferase, the pO157-encoded ecf is thermoregulated via an intrinsically curved DNA while the chromosomal lpxM is regulated by the PhoP/Q two component regulatory system. However, it is unclear why E. coli O157: H7 carries two copies of LPS myristoyl transferase that are differentially regulated. In this study, a whole genome-scale transcriptome specific to E. coli O157:H7 was carried out for identification of the genes differentially expressed in the amyristoylated E. coli O157:H7. The results identified a total of 110 EHEC genes that were up- or down-regulated in the amyristoylated E. coli O157:H7 strain, including genes associated with virulence (26.36%), metabolism (20.91%), transport (10.91%), signal transduction (4.55%), genetic information processing (3.64%), stress response (2.73%), regulatory function (2.73%), motility/adherence (3.64%), cell envelope (2.73%), cell division (1.82%) and ORFs of unknown function (17.27%). Of particular interest, the expression of LEE pathogenicity island genes was significantly influenced by LPS structural defects.
        4,000원
        185.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이논문은 음악의 요소들과 음악외적인 의미들을 이해하기위해 쟈크 데리다의 문자에관한 철학적인 이론을 적용한다. 데리다는 음성언어와 문자언어의 전통적인 이분법적인 대립에 대해 재해석을 한다. 그는 그 이분법적인 대립의 상하구조, 즉 서구의 형이상학 철학 체계 전반에 대해 반대로 생각해보고, 더 나아가서는 현실에서 잘못 인식되고 있는 점들의 변혁을 꽤한다. 이러한 인식론적 변혁을 꾀하는 것을 해체주의라 한다. 이 연구에서는 세 가지의 다른 대립에 대해 살펴본다 - 이항대립, 유표성, 그리고 음양이론. 이는 해체주의의 단계별 과정, 즉 텍스트를 이항대립으로 생각해보고, 이를 전위 시키고, 결국 사고의 변혁을 가져오게 하는 그 과정을 잘 묘사한다. 서양의 사고는 이항대립의 형태에서 심한 상하구조를 가지고있다. 즉, 어떤하나의요소는그반대의것을완전히지배하는구조이다. 이항대립에서는 근본적인 것이라고 여겨지는 요소가 주목을 받는다. 반면에, 유표성 이론에서는 어떠한 특별한 속성의 존재가 주목 받는다. 그래서 유표성 이론은 이항대립의 전위적인 특성을 보인다. 더 나아가 이항 대립의 전위는 음양이론으로 더 넓게 생각되어질 수 있다. 자연의 이치에서 음이 여성적이며, 어두운성격이라면양은남성적이며 밝음을 상징한다. 서로보충적인이러한힘은가까이서 보면 반대인 듯 하나, 크게 보면 유기체적으로 하나를 이룬다. 이는 결국 서로 다른 요소들이 조화를 이루게 됨을 나타낸다. 그러므로 음양의 동양적 사고는 이항대립적인 서양의 형이상학적 사고를 해체시킨다. 이러한 세가지 다른 대립들을 기초하여 Charles Ives’s General William Booth Enters into Heaven의 형식, 주선울, 리듬, 클라이막스 면에서 분석하고 어떤 요소들이 전위되고, 인식론적인 변혁을 가져왔는 지를 연구한다.
        8,900원
        188.
        2013.10 구독 인증기관·개인회원 무료
        Bumblebees are widely used to pollinate various greenhouse crops. Among the different bumblebee species, Bombus ignitus is indigenous to Korea, China, Japan and Russia. B. ignitus undergoes one generation per year, and artificial hibernation is essential for year-round rearing of the bumblebee. Keeping the queens under low-temperature conditions for several months is an effective method for terminating their diapause and promoting colony development. In the present study, we investigated how cold temperature affects the artificial hibernation of B. ignitus queens. Under chilling temperatures of -2.5°C, 0°C, 2.5°C and 5°C with constant humidity >80%, the queens stored at 2.5°C exhibited the highest survival rates, which were 74.0% at one month, 67.0% at two months, 60.0% at three months, 46.0% at 4 months, 33.0% at 5 months and 24.0% at 6 months. Lower survival rates were observed at 0°C, 5°C, 7.5°C and 12.5°C. At 2.5°C the colony developmental characteristics after diapause were 1.2- to 1.5-fold greater than those when queens were stored at 5°C. Thus, 2.5°C and 70% R.H. were the most favorable chilling temperature and humidity conditions for terminating the diapause of B. ignitus queens.
        189.
        2013.10 구독 인증기관·개인회원 무료
        We are currently developing the smart mosquito counter device (height 1080mm × width 560mm × diameter 320mm, 220V 60Hz 30W), which can attract the blood sucking female mosquitoes by emitting CO2 gas (300ml/min), can count the number of the captured mosquitoes by an infra-red beam area sensor, and can send the captured mosquitoes’ number through the CDMA module at real time. We operated the 8 – 16 devices with mosquito sensor networks and a server at the Youngdeungpo-gu areas in Seoul city of south Korea for three years (2011-2013) and we could efficiently control mosquitoes at the high mosquito density area based on the mosquito sensor’s data. We found that the accuracy of the device was about over 93% compared the real mosquito data and transmitted data by CDMA. We also found the water reservoir areas to control floods in Seoul metro city had relatively higher mosquito density than other normal areas, because those flat water areas were preferred by mosquitoes. Because our pest control office knew the mosquito occurrence peak times and areas from mosquito data transmitted by the mosquito sensor devices, we efficiently controlled mosquito larva and adults at the right time. We could accomplish very systematic mosquito control policy and we had the high credibility with the results. Based on the mosquito occurrence data, we selectively and scientifically controlled mosquitoes. Therefore, we reduced pesticide usage and saved annually pesticide expenses up to 2/3. Conclusively, if there is no mosquito, we don’t have to control mosquitoes.
        190.
        2013.10 구독 인증기관·개인회원 무료
        Since Linneaus (1758) named 4,162 species of living organism, 1.75 milion species have been described and named. It is less than 20% of the commonly accepted estimates of 10 million species on the planet earth. An average of 7,000 species per year was described during last 250 years, and, at this rate of species description, it will take another 1400 years to complete documentation of them. Who will do it? The real facing problem is the number of trained and practising taxonomists is declining worldwide at a time when demands for taxonomic science are increasing. A recent estimate suggests that the number of professional taxonomists worldwide is only 4,000-6,000 (Haas and Hauser, 2006). How about the situation is in Korea? In addition, the change of weather and the global warming accelerates more frequent invasion of harmful subtropical species, and taxonomist’s activity is needed more than ever. In shortly speaking, we are facing with a taxonomic “crisis” with erosion of taxonomy during last decades. The major reason is maybe that systematics has made little impact on the science with a narrow intellectual perspective, and most taxonomists have become accustomed to working on their speciality taxon without concern for relating their work to other broader environmental and societal issues in the facing with the global warming; e.g., invasive species, quarantine, use of bioresources, and ecosystem services. There is no question that taxonomy is the fundamental disciplines of biology, however, first of all, taxonomists should realize that how their research is related to other related sciences and how they make collaborative works. Especially, the basic taxonomic knowledge and skills generated by taxonomists is more needed to cope with the change of weather, due to the global warming which make critical change of the ecological structure in nature. In the presentation, the strategy for innovation of the living organism on our planet, with a crisis of taxonomy, will be discussed, and emphasized how taxonomists serve and contribute to other related topics. In addition, author will introduce his acitivity for innovation works on Lepidoptera, representing more than 500 new species and 23 new genera of moths described worldwide during last 40 years of his taxonomic research. The total number of new species described in Korea by him is 104 species, including 57 species of Gelechiidae, and more than 400 species and 22 new genera in the subtropical region, including Thailand, Vietnam, and New Guinea. Will it be possible to exceed 500 insect species described worldwide by a taxonomist in future?
        191.
        2013.09 구독 인증기관 무료, 개인회원 유료
        소듐 2-브로모에탄술포네이트를 이용한 2-에티닐피리딘의 무촉매중합을 통하여 새로운 이온성 폴리아세틸렌을 합성하였다. 중합반응은 균일하게 진행되었으며 높은 수율 (중합수율: 78%)로 해당고분자를 합성하였다. 반응 초기 사차 염화과정에서 생성된 활성화 N-(에틸술포네이트 소듐)-2-에티닐피리디늄 브로마이드가 중합반응의 단량체로 참여하고 있는 것으로 밝혀졌다. 고분자의 분자 구조를 여러 가지 분석기기로 확인한 결과 설계한 치환기를 갖는 폴리아세틸렌 유도체가 합성되었음을 확인할 수 있었다. 합성 고분자의 고유점도는 0.12-0.15 dL/g 범위였으며 X-선 회절분석 결과 무정형상임을 확인할 수 있었다. 고분자의 광발광 피크가 593 nm에서 관찰되었는데, 이는 2.09 eV의 광에너지에 해당한다. 이 고분자는 도핑과 탈도핑 피크 사이에서 비가역 전기화학적 거동을 보였다.
        4,000원
        192.
        2013.06 구독 인증기관 무료, 개인회원 유료
        A two-year-old, castrated male Jindo dog presented with a three-week history of non-pruritic alopecia and scales on dorsum. The dermatologic lesions were progressive and did not respond to antibiotics and treatment for ectoparasite. Silver-white scales were adhered to the hair shafts and a follicular cast was marked on a trichogram. Findings on histopathologic examination of the skin lesions were consistent with sebaceous adenitis. Treatment with systemic cyclosporine and topical shampoo treatment was recommended for long term management. This case report is the first to describe a sebaceous adenitis in our country and suggests combination treatment approaches to long term management of this disease.
        3,000원
        193.
        2013.05 구독 인증기관 무료, 개인회원 유료
        We designed a dual type stick from a universal design point of view for the aged who need walking sticks. The dual type stick is a differentiated walking stick different from the existing walking sticks because it is a walking assistance device with stability and convenience that can be used for flatland gait and step gait for the aged. This research as one of the processes of capstone design is conducted by utilizing 3D rendering, 2D design, stress analysis using inventor according to stick materials, and a 1/4 scale mock-up product.
        3,000원
        194.
        2013.04 구독 인증기관·개인회원 무료
        Bumblebees are important pollinators of crops and wildflowers in northern temperate regions. The number of bumblebee species has declined in recent decades, particularly, in developing regions. Here, we investigated the distribution and floral preferences of founder bumblebee queens that were collected between 2000 and 2012 in Korea with the intention of gathering information useful in the conservation of native bumblebee populations. A total of 13,130 overwintered bumblebee queens were collected at 63 locations from 8 provinces; the collected bumblebees consisted of five species of native bumblebees (Bombus ardens, B. ignitus, B. hypocrita spporoensis, B. ussurensis and B. consobrinus wittenburgi) and one species of exotic bumblebee (B. terrestris). The dominant species were Bombus ardens Smith and Bombus ignitus Smith, which accounted for 7,462 (56.8%) and 3,725 (28.4%) of the collected bumblebees, respectively. As a proportional distribution of the founder bumblebee queens that were collected, B. ignitus was the most common (9.8%-78.5%), followed by B. ardens (9.8%-66.1%), B. hypocrita spporoensis (0.9%-31.4%), B. ussurensis (0.8%-22.2%), B. consobrinus wittenburgi (0.1%-3.8%) and B. terrestris (0.0%-1.1%). The bumblebee queens foraged from 7 families of plants and 18 plant species. B. ignitus bumblebees were primarily collected from Prunus serrulata Matsumura and Corydalis speciosa Max, and B. ardens bumblebees were primarily collected from Rhodldendron mucronulatum Turcz and Prunus yedoensis.
        195.
        2013.04 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is one of the major insect pests of cucumber, Cucumis sativus L. The spatial distribution and occurrence of Aphis gossypii Glover on greenhouse cucumber, Cucumis sativus L., were studied to provide an efficient and reliable sampling plan for its control. A highly clumped pattern was observed among plants (TPL b = 1.63) within a greenhouse. To develop a sampling plan for visual enumeration, leaves within plants were selected by different percentages of leaves (eg., 3rd and 6th, 6th and 9th leaf,…from the bottom of the plant) and then compared the accuracies and efficiencies by relative net precision (RNP). The results indicated that selecting leaves from the bottom of the plant by systemic sampling methods were relatively high as other sampling methods.
        196.
        2013.03 구독 인증기관 무료, 개인회원 유료
        Receptor activator of NF-κB ligand (RANKL) is an essential cytokine for osteoclast differentiation, activation and survival. T lymphocytes such as T17 cells, a subset of T helper cells that produce IL-17, play an important role in rheumatoid arthritic bone resorption by producing inflammatory cytokines and RANKL. It has not yet been clearly elucidated how T cell activation induces RANKL expression. T cell receptor activation induces the activation of nuclear factor of activated T cell (NFAT) and expression of its target genes. In this study, we examined the role of NFAT in T cell activation- induced RANKL expression. EL-4, a murine T lymphocytic cell line, was used. When T cell activation was induced by phorbol 12-myristate 13-acetate (PMA) and ionomycin, RANKL expression increased in a time-dependent manner. In the presence of cyclosporin, an inhibitor of NFAT activation, this PMA/ionomycin‐induced RANKL expression was blocked. Overexpression of either NFATc1 or NFATc3 induced RANKL expression. Chromatin immunoprecipitation results demonstrated that PMA/ionomycin treatment induced the binding of NFATc1 and NFATc3 to the mouse RANKL gene promoter. These results suggest that NFATc1 and NFATc3 mediates T cell receptor activationinduced RANKL expression in T lymphocytes.
        4,000원
        197.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        제초제 저항성 유전자가 도입된 형질전환 토마토에서 T-DNA의 특성을 분석하였다. 형질전환 토마토의 T-DNA 도입형태를 분석하기 위한 primer쌍을 제작하여 rpPCR을 실시하 였다. T0-21(15:1, 4 copy), 26(3:1, 3 copy), 34(63:1, 4 copy)의 경우에는 5쌍의 primer를 이용하여 수행한 rpPCR 결과에서 양쪽이 절단된 불완전한 T-DNA 반복이 확인되었다. 도입된 T-DNA의 주변 서열 및 분포를 알아보기 위하여 총 52개체의 형질전환체에 대하여 TAIL-PCR을 실시하였다. 이 중 22개 형질전환체의 TAIL-PCR 산물의 염기서열을 분석하였는데, 2개의 형질전환체에서 나온 염기서열 결과는 토마토의 12번 염색체와 90%, 1개체는 토마토 clone 135006R과 98%, 5개체는 담배의 엽록체와 97% 상동성을 보였으며, 12개체는 다양한 vector의 염기서열을 나타내었고, 그 외 나머지 개체들은 토마토 유전체 정보와 는 유사성을 찾을 수 없었다.
        4,000원
        198.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1. 세계 26개국에서 도입된 녹두 유전자원 705점에 대하여16개의 형태적 형질 특성을 이용하여 각각 두 가지의 군집방법, 핵심집단 자원수 결정방법 및 표본추출 방법을 조합하여 총8개의 핵심집단(SUNPR, SUNPPr, UNPR, UNPPr, SUNLR, SUNLPr, UNLR, UNLPr)을 작성하여 원수집단과 비교한바 8개핵심집단 모두 원수집단과는 분산과 평균치에서 차이가 없었다. 2. Nei의 다양성지수는 8개 핵심집단 모두 원수집단 보다높았고, 특히 UNLPr이 가장 높았으며, UNPR은 다른 핵심집단에 비하여 상대적으로 낮은 지수를 보였다. 3. 원수집단과 핵심집단간 자원분포의 동질성을 파악하기 위하여 카이자승 검증을 한 결과 12개 양적형질과 1개의 질적형질(종피색)은 모든 핵심집단이 동질분포를 보였으나 3개의질적 형질 (배축색, 종피광택, 생육습성)은 핵심집단에 따라서동질분포를 하는 것과 그렇지 않은 것이 있었으며, 8개 핵심집단 중 UNPPr은 동질성이 가장 높았다. 평균차율(MD%)과일치율(CR%)은 8개 핵심집단 모두 유의한 수준을 보였다. 4. 8개의 모든 핵심집단이 원수집단과 평균치에서 차이가 없고, 높은 다양성을 과 동질한 분포를 보이며, 평균차율(MD%)과 일치율(CR%)이 유의한 수준을 보여 원수집단의 다양성을잘 나타내는 것으로 해석되었다. 5. 핵심수집단 크기(10%와 15%)에 따른 다양성은 유의한차이가 없었으며, 8개의 핵심집단 중 평균치, 동질분포, 일치율 및 도복내성을 고려할 때 UNPPr이 가장 좋은 핵심집단으로 사료되었다.
        4,300원
        199.
        2012.10 구독 인증기관 무료, 개인회원 유료
        In product process it is agreeable to testify and reflect the customer's needs in design and function and to create attractive quality factor effectively. In this study used KANO model to catch the excellent quality factors in SmartPhone and aimed to help design. We made a survey and performed customer factor analysis.
        3,000원
        200.
        2012.10 구독 인증기관·개인회원 무료
        Allomyrina dichotoma is a typical pet beetles in Korea. From 2010, similar symptoms of milky spore disease were found collectively in grubs of the species reared in insect farms. They shared a specific symptom that the skin of last instar larvae was changed softer with opaque white and infested grubs eventually died. To clarify the cause of the symptom, we collected the larvae of A. dichotoma from five farms and examined intestinal bacterial florae of them using pyrosequencing technique. From those results, a member of Paenibacillus was found only in the larvae showing the symptom of disease. Through PCR analysis using a Paenibacillus specific primer set, we obtained the partial 16S rRNA gene sequence and confirmed the microbe as Paenibacillus sp. For detailed characterizing, a whole guts was extracted from each larva showing the sign of the disease and incubated at 70℃ for 15 min to isolate spore forming bacteria. After then, each content of guts was cultured on MYPGPNAL agar medium (12.5 μg/ml of nalidixic acid) at 30℃. The 16S rRNA gene sequence analysis for six isolate showed that they were closely related to P. rigui (97.5~98.0% similarity) and to P. chinjuensis (95.9~96.6% similarity). Additional tests including API test and cellular fatty acid composition analysis were performed, but the strain couldn’t be identified at species level, suggesting it may represent novel species of the genus Paenibacillus.