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        검색결과 68

        41.
        2005.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        방사성폐기물 시료 중 Am 과 Cm 을 정량하기 위하여 음이온교환수지 및 DTPA-lactic acid 용리액을 사용하는 HDEHP 추출크로마토그래피로 이들 핵종을 분리하였다 분리된 핵종은 황산염 매질에서 전착한 다음 알파분광분석법으로 각 핵종의 방사능을 측정하였다. 모의 시료용액 중 Am 및 Cm 을 측정한 결과 각각 85.2 및 86.3 의 회수율을 나타내었다. 본 방법을 방사성 농축폐액 시료에 적용하여 Am 과 Cm 을 정량한 결과 각각 1.5-1.9 Bq/g 및 -1.7 Bq/g 의 방사능 값을 나타내었다.
        4,000원
        43.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Construction Management(CM) that is the business innovation and method of construction management is introducing and implying the needs to improve high cost and low productivity structure and cope with very variable changes of construction market in construction industry within the country. But, safety management system is a very insignificant thing under CM. Consquently, We had been needed for the improvement about what the problem was. Therefore, My study raised the problem to the system and management by making a comparative study of the feature of the management method and the content of the accomplishment of safety management by using the consideration of the case about a big field of construction work implying CM within the country and proposed the active method of safety management.
        4,300원
        44.
        2004.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have searched for HI 21 cm line emission from shocked atomic gas associated with southern supernova remnants (SNRs) using data from the Southern Galactic Plane Survey. Among the 97 sources studied, we have detected 10 SNRs with high-velocity HI emission confined to the SNR. The large velocity and the spatial confinement suggest that the emission is likely from the gas accelerated by the SN blast wave. We also detected 22 SNRs which show HI emission significantly brighter than the surrounding regions over a wide (>10 km s-1) velocity interval. The association with these SNRs is less certain. We present the parameters and maps of the excess emission in these SNRs. We discuss in some detail the ten individual SNRs with associated high-velocity HI emission.
        5,100원
        45.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study suggests a safety management model for construction management (CM) suitable to domestic conditions so that inefficiency resulted from the operation of construction projects by public and private institutes according to different systems can be eliminated for the securing of systematic and efficient safety management. Based on the suggested safety management model, this study also develops a safety management information system that can efficiently and consistently manage and maintain a large quantity of information, and give necessary supports in a speedy way in the managing of construction projects.
        5,100원
        46.
        2003.11 구독 인증기관 무료, 개인회원 유료
        Construction Management(CM) system, which was introduced some years ago to large national construction projects, such as the construction of Incheon New Airport, construction of high-speed railroad and World Cup stadiums, is considered to be still in its early stage and safety at each step of CM is very poorly controlled. In an attempt to improve such inferior safety management of domestic CM, this study made comparative analysis about operation system of safety management with CM system in domestic and abroad. Also suggested the model under consideration with CM, which is suitable for the situation of Korea.
        4,200원
        47.
        2003.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Construction Management(CM) system, which was introduced some years ago to large national construction projects, such as the construction of Incheon New Airport, construction of high-speed railroad and World Cup stadiums, is considered to be still in its early stage and safety at each step of CM is very poorly controlled. In an attempt to improve such inferior safety control of domestic CM, this study analyzed safety control operation system in CM home and abroad and suggested a model for the construction of safety control management information system suitable to the conditions of Korea.
        4,200원
        48.
        2003.05 구독 인증기관 무료, 개인회원 유료
        오늘날 건설산업분야는 기술적인 것은 물론 경제, 정보면에서도 그 어느때보다 치열한 경쟁 상태에 직면하고 있다. 이러한 건설산업 전반의 무한 경쟁에서 대응할 우수한 기술력과 체계적인 건설사업관리(CM)기법에 따른 안전관리가 필요한 실정이다. 따라서 CM단계별 안전관리지침이 시설물 life cycle 전단계에 걸쳐 활용되는 방안에 대해 연구하고 각 단계별 안전관리를 유도하여 안전성확보에 주력하며 각단계별 Safety management를 하고자 한다.
        4,000원
        49.
        2002.05 구독 인증기관 무료, 개인회원 유료
        최근 우리나라의 건설산업은 Project의 규모가 대형화됨에 따라 기계화 시공 신공법 도입등 공정작업이 다양해지고 새로운 방법들이 많이 시도되고 있으며 건설산업도 기획, 설계, 발주, 시공, 유지관리라는 연속적 단계를 통하여 각 단계가 상호 유기적 연관성을 가지므로 건설현장의 근원적 안전성 확보를 위해서 건설 시설물의 Life cycle 전 단계를 걸쳐 안전관리 개념과 기법이 도입되어야 한다. 따라서 본 연구에서는 CM에 의한 단계로 안전성 확보에 주력하고 미국 CMAA의 단계별 기능별(phase, 6Function) 업무내용에서와 같이 Safety Management를 한다. 또한 CM제도 정착에 따른 초기단계를 규정하는 안전관리 법령 재정을 하여 단계적으로 자율적 안전 관리를 유도하여 재해예방을 하도록 해야한다.
        4,000원
        51.
        1997.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We carried out high-resolution(FWHM=3' .3) HI 21 cm observations of the supernova remnant(SNR) PKS0607+17 and HII region S261 using Arecibo 305-m telescope. The observation was to investigate whether the high-velocity(HV) gas detected in the southern area of PKS0607+17 by Koo & Heiles(1991) is physically associated with the SNR or not. The velocity of the HV gas ranges from +64 km/s to +87 km/s, which is difficult to result from the Galactic rotation. The HV gas could be the gas accelerated by supernova blast wave. However, because the observation of Koo and Heiles(1991) was carried out using Hat Creek radio telescope(FWHM ≃ ≃ 36'), the association of the HV gas with the SNR could not be investigated. Using the Arecibo HI 21cm data, we have found that the HV gas appears m the southern part of the SNR and its velocity ranges from +61 km/s to +77 km/s. But the HV gas is scattered m the whole field, not only toward PKS0607+17 but also outside the SNR Accordingly the HV gas is probably not associated with the SNR, but is accidentally aligned along the same line of sight toward the SNR. Instead we have found that HI clouds at low velocities could be possibly associated with the SNR. In Arecibo HI 21cm channel maps the HI gas seems to surround the southern boundary of the SNR at VLSR VLSR = +19.6 ~ +40.2 km/s. But because the region of the Arecibo HI 21cm observation is not wide enough to examine the HI gas distribution, we investigated this area using the Berkely low-latitude HI survey data(Weaver & Williams 1974) too. There we found HI gas surrounding the radio continuum boundary of PKS0607+17 at VLSR VLSR = +21.6 ~ +258 km/s. It is possible that this HI gas is associated with the SNR, in which case, the velocity of the SNR Vo Vo ≃ ≃ +26 km/s, its distance d ≃ ≃ 12.5 kpc and its radius R ≃ ≃ 145 pc. If we assume that the expansion velocity is ~10 km/s, then the age of the SNR is ∼4.4×106 ∼4.4×106 years. PKS0607+17 could be one of the oldest SNRs in the Galaxy. We also studied HI propertities of the HII region S261, which is ∼1∘ ∼1∘ away from PKS0607+17. There has been no high-resolution m 21 cm observational study on S261. We discovered HI cloud located at the north-eastern part of S261 at VLSR VLSR = +5 km/s ~ +10 km/s, which is possibly associated with the HII region. The central velocity of the HI cloud VLSR VLSR = +7.2 km/s and the corresponding distance d = 1.5 kpc. This velocity is comparable to the radio recombination line velocities.
        5,800원
        52.
        1996.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A new CCD camera equipped with a large format chip is now under construction for the Kiso 105-cm Schmidt telescope. We use SITe TK2048E, of which pixel size is 24 μm and chip size is 48 mm square. TK2048E is thinned back-illuminated so that it has high sensitivity in U-band. The chip is cooled by a refrigerator instead of liquid nitrogen. MESSIA III is used as CCD control system.
        3,000원
        55.
        1993.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We developed an Automatized Differential Photometry System (ADPS) to achieve high time resolution and high efficiency in the photometric observations of short period variable stars. This ADPS has been introduced to the CCD camera system attached to the 6lcm Reflector at Sobaeksan Astronomy Observatory. Several new algorithms were devised for the controlling the telescope. the star recognition in a CCD frame and the aperture photometry, etc..As the result, the differential photometric observation was fully automatized without any manual control, and much faster data acquisition could be achieved over the conventional photoelectric differential photometry.
        4,500원
        56.
        1993.12 구독 인증기관·개인회원 무료
        57.
        1993.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We made a pyramidal horn antenna system for 21cm cosmic radio wave. The antenna system has a rectangular waveguide with TE10 TE10 mode and a copper probe to detect the electromagnetic wave in waveguide. The parameters of the probe are obtained by experiments using two waveguides. Pyramidal horn antenna is designed to get a gain of 20dB. The size of the aperture of this horn is 94cm×74cm 94cm×74cm . The beam width of half power is about 14.7∘ 14.7∘ for the frequency of 1.4GHz. The horn is made of aluminum plate with a thickness of 2mm. The signal from horn and waveguide is amplified in a receiver system and is converted into DC in the detecter. The intensity of the signal is recorded on a chart recorder. We observed the sun using this simple radio telescope and obtained the brightness temperature of 2.2×105K 2.2×105K , which indicates that the sun is quiet at 21cm.
        4,800원
        58.
        1993.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chitin was isolated from crab shells by modified Hackman's method, which was treated again with aqueous sodium hydroxide solution to give alkali chitin(sodium alkoxide of chitin). And after, the alkali chitin is allowed to react with monochloroacetic acid to synthesize 6-O-(carboxymethyl) chitin [CM-Chitin] under diminished pressure. In order to synthesize high performance CM-Chitin as hygroscopic agent, it was measured that the yield and degree of subsititution of each CM-Chitin according to molar ratio(monochloroacetic acid equivalent mol/N-acetyl-D-glucosamine residue) and their moisture-absorption and moisture-release properties were measured and compared with those of hyaluronic acid. The moisture-absorption and moisture-release properties of CM-Chitin, especially 0.8 in degree of substitution, were found quite similar to those of hyaluronic acid. The preliminary results show that CM-Chitin might be used as hygroscopic agent instead of hyaluronic acid in field of cosmetics.
        4,000원
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