• Title/Summary/Keyword: 전기특성

Search Result 27,099, Processing Time 0.058 seconds

Comparison of Horizontal and Vertical Noise Power Spectrum in Measurements by Using Various Electronic Portal Imaging Devices in Radiation Therapy (방사선치료 시 전자포털 영상장치를 이용한 잡음전력스펙트럼 수평 및 수직 측정비교)

  • Kim, Ki-Won;Choi, Kwan-Woo;Jeong, Hoi-Woun;Jang, Seo-Goo;Kwon, Kyung-Tae;Son, Soon-Yong;Son, Jin-Hyun;Min, Jung-Whan
    • Journal of radiological science and technology
    • /
    • v.39 no.2
    • /
    • pp.171-176
    • /
    • 2016
  • The quality assurance (QA) is very important for diagnostic field and radiation therapy field to evaluate the characteristic of devices. The purpose of this study was to compare different NPS methodologies results which are measuring NPS with regard to horizontal and vertical directions by using megavoltage X-ray energies. The NPS evaluation methods were applied to the International Electro-technical Commission standard (IEC 62220-1). The electronic portal imaging devices (EPID) devices such as Siemens BEAMVIEW$^{PLUS}$, Elekta iViewGT and Varian Clinac$^R$ iX aS1000 were used. NPS data were expressed by corresponding each frequency about average of noise value corresponding the each frequency, and NPS were evaluated quantitatively by totaling up the noise values of average frequency which are on horizontal and vertical directions. In NPS results for Elekta iViewGT, NPS of horizontal and vertical by using 4 methods were indicated the difference of 3~5% between horizontal and vertical direction. In the results of Siemens BEAMVIEW$^{PLUS}$ and Varian Clinac$^R$ iX aS1000, the NPS of horizontal and vertical direction were indicated the difference of 15% when averaging the whole values. This study were evaluated the NPS of each devices by totaling up the noise values of average frequency which are on horizontal and vertical directions suggesting the quantitative evaluation method using the data.

History of Guard System during the Period of Military Rule in the Goryeo Dynasty (고려 무신집권기 호위제도의 경호학적 고찰)

  • Lee, Sung-Jin;Cho, Sung-Jin
    • Korean Security Journal
    • /
    • no.34
    • /
    • pp.233-258
    • /
    • 2013
  • In the early days of the Goryeo Dynasty, the royal guard was comprised of the central regular army in the 2-gun-6-wi system, and Nasungeomgun was in charge of the security inside the palace. However, the military system became disorganized during the period of military rule and the royal guard had to rely on military subjects. The military officials suppressed the civil ministers centering on Jungbang, the guarding organization close to the King to incapacitate the royal authority and control the state affairs. When the rule of the three leaders of the military rule became short-lived and Dae-seung Gyeong is raised to the ruler, he organized a do-or-die squad comprised of a hundred and more people for his personal safety, and this became the first dobang. Dobang was disassembled after Dae-seung Gyeong died of disease, but under the rule of Chung-heon Choe, Dae-seung Gyeong's dobang was revived and reinforced into 'Yukbeon Dobang' to provide the ruler with personal protection and intensify the ruling system, and it was quite a large organization with more refined system. Yukbeon Dobang was expanded and reinforced into Naeoedobang under the rule of Woo Choe, the son of Chung-heon Choe, and it was enhanced even more into Dobang Samsipyukbeon System under the rule of the grandson, Hang Choe. Dobang can be considered as the guard organization in modern sense, and it collected information and surveyed the area where guarding is required and house troops that belonged to Naedobang eliminated the risks that may follow afterwards to make assurance doubly sure for guarding. The Choe's regime established Mabyeolcho as a private guard organization in addition to dobang, and this formed the cavalry and infantry units with dobang. Yabyeolcho organized by Woo Choe in the reign of King Gojong was divided into Joabyeolcho and Ubyeolcho, and later Sineuigun was integrated with them to form Sambyeolcho. Originally, Yabyeolcho was established under the rule of Woo Choe to prevent crime in the evening, but after Sineuigun was organized with the ones who were captured by Mongolian army but escaped, in other words when Sambyeolcho was organized, the organization displayed much broader influence by covering military and police affairs as well as punishment and imprisonment. The guarding organization during the Period of Military Rule in the Goryeo Dynasty did not have strict distinction between official guard and personal guard. The private guard in modern days which is the equivalent of personal guard is characterized by its commerciality, however, house troops and the members of dobang did not seem to pursued profit. The guard organization during the period of military rule started from dobang which was organized for personal safety but gradually developed publicness through the participation of civil ministers and expansion, and later it played the pivotal role for social security serving official purpose up to the level where the distinction between official and private activities was blurred during the period of Sambyeolcho.

  • PDF

Growth and characterization ofZnIn$_2S_4$ single crystal thin film using hot wall epitaxy method (Hot Wall Epitaxy(HWE)에 의한 ZnIn$_2S_4$ 단결정 박막 성장과 특성)

  • 최승평;홍광준
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.11 no.4
    • /
    • pp.138-147
    • /
    • 2001
  • The stochiometric mixtures mixture of evaporating materials for the $ZnIn_{2}S_{4}$ single crystal thin film was prepared from horizontal furnace. To obtain the $ZnIn_{2}S_{4}$ single crystal thin film, $ZnIn_{2}S_{4}$ mixed crystal was deposited on throughly etched semi-insulting GaAs(100) in the Hot Wall Epitaxy(HWE) system. The sourceand substrate temperature were $610^{\circ}C$ and $450^{\circ}C$, respectively and the growth rate of the $ZnIn_{2}S_{4}$ single crystal thin film was about 0.5$\mu\textrm{m}$/hr. The crystalline structure of $ZnIn_{2}S_{4}$ single crystal thin film was investigated by photoluminescence and double crystal X-ray diffraction (DCXD) measurement. The carrier density and mobility of $ZnIn_{2}S_{4}$ single crystal thin film measured from Hal effect by van der Pauw method are $8.51{\times}10^{17}{\textrm}{cm}^{-3}$, 291$\textrm{cm}^2$/V.s at $293^{\circ}$K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the $ZnIn_{2}S_{4}$ single crystal thin film, we have found that the values of spin orbit splitting $\Delta$So and the crystal filed splitting DCr were 0.0148eV and 0.1678 eV at $10^{\circ}$K, respectively. From the photoluminescence measurement of $ZnIn_{2}S_{4}$ single crystal thin film, we observed free excition($E_{X}$) typically observed only in high quality crystal and neutral donor bound exicton ($D^{\circ}$, X) having very strong peak intensity. The full width at half maximum and binding energy of neutral donor bound excition were 9meV and 26meV, respectively. The activation energy of impurity measured by Haynes rule was 130meV.

  • PDF

Growth and optical conductivity properties for MnAl2S4 single crystal thin film by hot wall epitaxy method (Hot Wall Epitaxy(HWE)법에 의한 MnAl2S4 단결정 박막 성장과 광전도 특성)

  • You, Sangha;Lee, Kijeong;Hong, Kwangjoon;Moon, Jongdae
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.24 no.6
    • /
    • pp.229-236
    • /
    • 2014
  • A stoichiometric mixture of evaporating materials for $MnAl_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MnAl_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MnAl_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.7920eV-5.2729{\times}10^{-4}eV/K)T^2/(T+786 K)$. In order to explore the applicability as a photoconductive cell, we measured the sensitivity (${\gamma}$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation (MAPD) and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in S vapour compare with in Mn, Al, air and vacuum vapour. Then we obtained the sensitivity of 0.93, the value of pc/dc of $1.10{\times}10^7$, the MAPD of 316 mW, and the rise and decay time of 14.8 ms and 12.1 ms, respectively.

Comparison of the High Concentration Calcium Chloride(CaCl2) Salt Reduction Effect of Soil Amendment Agent and Planting Pennisetum alopecuroides (토양개량제와 수크령 식재에 따른 고농도 염화칼슘 염분저감 효과 비교)

  • Yang, Ji;Park, Jae-Hyeon;Yoon, Yong-Han;Ju, Jin-Hee
    • Korean Journal of Environment and Ecology
    • /
    • v.34 no.4
    • /
    • pp.345-354
    • /
    • 2020
  • The purpose of this study was to investigate the effects of soil amendment treatments, such as hydroball, and active carbon, and planting Pennisetum alopecuroides for reducing calcium chloride (CaCl2) of soil leachate and the growth of Pennisetum alopecuroides. The experiment planted Pennisetum alopecuroides in a plastic pot with a diameter of 10 cm and a height of 9 cm in a greenhouse April-October 2018. The experimental group comprised six treatments, including Non-treatment (Cont.), Hydroball (H), Active carbon (AC), planting Pennisetum alopecuroides (P), hydroball + planting Pennisetum alopecuroides (H + P), and active carbon + planting Pennisetum alopecuroides (AC + P). The dissolution of the CaCl2 concentration 200ml of 10g/L was irrigated once every two weeks. We measured the growth (plant height, leaf length, leaf width, number of leaves), EC, pH, and exchangeable cations (K+, Ca2+, Na+, and Mg2+) according to the high concentration of CaCl2 in the plant and soil leachate. In a treatment with the 'hydroball' amendment, the soil leachate electrical conductivity (EC), and the cation exchangeable were decreased more than those of the control, while the growth of Pennisetum alopecuroides relative growth rate(RGR) increased. Overall, application with the hydroball amendment added the planting of Pennisetum alopecuroides improved the salt reduction effect more than the control group. These results indicate that the application of the soil amendment agent hydroball was suitable soil amendments in accordance with the high concentration of calcium chloride (CaCl2). Also, Planting Pennisetum alopecuroides is expected to be appropriate for salt-tolerant plant for soil affected by deicing salt agents.

Changes In Protein and Its Components of High and Low Protein Varieties during Seed Development and Maturation of Soybeans (대두(大豆) 고저단백질(高低蛋白質) 품종(品種)의 성숙중(成熟中) 종실(種實)의 발육(發育)과 단백질(蛋白質) 및 그 구성분(構成分)의 변화(變化))

  • Lee, Jong Suk
    • Korean Journal of Agricultural Science
    • /
    • v.5 no.2
    • /
    • pp.56-67
    • /
    • 1978
  • This study was conducted to characterize comparatively the accumulative patterns of protein and oil, temporal changes in electrophoretic components of proteins during seed development and maturation for the soybean varieties with high, medium and low protein contents. 1. The dry matter of the developing seed increases slowly for the first 22 days after flowering, followed by rapid linear increase for 20 to 30 days and further slow increase for 5 to 15 days attaining its maximum. During the period 12 to 27 days after flowering the protein content of seed increases rapidly while oil content increases rapidly. Following this period of rapid changes, there was period of slow increase until 40 to 47 days after flowering and no seizable further change in the content of both protein and oil. 2. The high protein variety, Saikai # 20, was characterized by shorter period and lower rate of decrease in protein content during the early period, followed by longer period and higher rate of increase in protein content, with earlier stop of oil accumlation during the seed development. 3. The low protein and high oil variety, Shelby, was characterized by longer period of decrease in protein content and shorter period of increase in protein content in contrast to the longer period of slow oil increase during seed development. 4. The temporal pattern of protein component accumulation during seed development was distinctly different among varieties differing in protein content. The time of distinct appearance of all the protein components identifiable in the matured seeds was in accordance with the end of d crease in the protein content of seed. A component having Rm of 0.03 which was absent in the matured seeds was identifiable during the first 17 days after flowering. 5. The high protein variety, Saikai # 20, had much higher compositioral ratio of the component a from the early days of seed development and it continued to increase until 47 days after flowering, while the increase in the composition of the component a stopped as early as 27 days after flowering in the other lower protein varieties. 6. The composition of the component b increased during the period from 17 to 42 days after flowering in all the varieties tested, but the rate of increase during the period was lowest in the high protein variety, Saikai # 20.

  • PDF

Characterization of Bovine Lymphocyte Antigen DRB3 exon2 Gene of Korean Native Cattle (한우의 BoLA DRB3 exon2 유전자의 특성)

  • Kang, Ho Bum;Ryoo, Seung Heui;Lee, Sang Hoon;Jeon, Byung Soon;Sang, Byung Chan
    • Korean Journal of Agricultural Science
    • /
    • v.25 no.1
    • /
    • pp.79-88
    • /
    • 1998
  • This study was performed in order to apply to effective breeding of Korean native cattle on the molecular genetic level obtained from PCR and nucleotide sequencing analysis of BoLA DRB3 exon2 that has important roles in host immune defence. Genomic DNA used in this study was prepared from the blood of Korean native cattle in Korean Native Cattle Improvement Center of National Livestock Cooperation. The results obtained from this study are summarized as follows: 1. Genomic DNA extracted from the blood of Korean native cattle was subjected to electrophoresis on 1.5% agarose gel. Major band was bigger than 12.2kb, indicating that genomic DNA was well prepared for PCR. Amplified products of 284bp fragments was obtained the amplification of BoLA DRB3 exon2 gene by PCR. 2. Cloning of BoLA DRB3 exon2 of Korean native cattle with pCR2.1 vector was conformed by 300bp fragment from recombinent plasmid that restricted with enzyme digestion of EcoRI. 3. Homology of BoLA DRB3 exon2 alleles of parent was 82.0% between sire's alleles and 90.1% between dam's alleles. 4. In pedigree analysis using BoLA DRB3 exon2 gene, sequencing result of BoLA DRB3 exon2 genes showed inheritance by Mendelian mode through the parents to their offspring. 5. Taking together those experimental results, pedigree was confirmed on the basis of sequencing for the alleles of parents and offspring. This knowledge by the molecular biological approach could be served for the improvement of Korean native cattle.

  • PDF

The Analyses of Geographers지 Roles and Demands in Korean GIS Industries (GIS 산업에 있어서 지리학의 역할 및 수요에 대한 분석)

  • Chang Eun-mi
    • Journal of the Korean Geographical Society
    • /
    • v.39 no.4
    • /
    • pp.643-664
    • /
    • 2004
  • This study aims to review what geographers have contributed to GIS industries and national needs. To-be-geographers and geographers are expected to meet the gap between what we have teamed in school and what we have to do after graduation. The characteristics of GIS industry in the 1990 are summarized with approximate evaluation of the contribution of geographers in each stage. Author introduced the requirement for the licenses of geomatics and geospatial engineering experts and the other licenses, which are important to get a job in GIS industry from 2003 to 2004. A set of questionnaire on the user's requirements was given to GIS people in private companies and public GIS research centers and analyzed. Author found that they put an emphasis on hands-on experiences and programming skills. no advantages or geography such as capability or integration and inter-disciplinary collaboration were not appreciated. The prospects for the GIS tend to be positive but the reflectance of the prospect was not accompanied by at the same degree of preference for geography. Most government strategies for the next ten years' GIS focus on new-growth leading industries. SWOT(strength, weakness, opportunity, threat) analysis of geography for GIS industry will give some directions such as telematics, regional marketing strategies with web-based GIS technology, location based service. That means intra-disciplinary study in geography will evoke the potentiality of GIS, compared with interdisciplinary studies.

Brewing and Quality Characteristics of Korean Traditional Grape Wine (한국 전통포도주의 제조와 품질특성)

  • Kang, Seong-Gook;Yang, Eun-Jung;Jo, Gwang-Ho;Park, Yang-Kyun;Jung, Soon-Teck
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.37 no.8
    • /
    • pp.1030-1036
    • /
    • 2008
  • In Korea, many types of traditional grape wine have existed starting from seven hundred years ago and horse-blossom-like-grape (mayu-podo) was mainly cultivated. Korean traditional wine (KTW) was manufactured by a unique method in which grape juice-added porridge made from glutinous rice was fermented by nuruk as a starter for brewing. Unfortunately, KTW making was discontinued in 20th century; thus, restoration of Korean wine culture is needed. KTWs were prepared by four traditional methods, and their qualities were compared to commercial wine made by sugaring grape juice. Ethyl alcohol contents, total acidity, pH and amino acid of the four KTWs were $9.2{\sim}11.2%$, $0.93{\sim}1.20\;mg$/100 mL, $3.02{\sim}3.48$ and $0.80{\sim}0.88\;mg$/100 mL respectively. The KTWs showed higher values in total acidity and amino acid than those of commercial grape wine. KTWs were rich in maltose, acetic acid and lactic acid. L, a and b value in Hunter's color value ranged $3.59{\sim}3.69$, $20.63{\sim}38.06$, and $1.20{\sim}1.56$, respectively. Sensory quality properties in color, flavor, taste and overall of KTWs were not different from commercial dry wine. Contents of total phenolic compounds and free radical scavenging activity using DPPH of KTWs were $599.6{\sim}652.2\;mg$/100 mL and $50.59{\sim}56.75%$, respectively.

Reactivities of Di-iso-butylnitrosoamine by Anodic Film Formed on Metals (산화피막전극을 이용한 디이소부틸니트로소아민의 전극반응)

  • Hwang Kum-Sho
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.14 no.2
    • /
    • pp.94-102
    • /
    • 1981
  • To investigate the characteristics of anodic film formed on metals and the reactivities of organic inhibitor Di-iso-butylnitrosoamine (DBNA) in sea water. the cathodic reactions of anodic film formed on metals were carried out by using the potential drop method and galvanostatic method at $25^{\circ}C$. The investigated results are as follows: The anodic films formed on aluminum and zinc in 60mM $DBNA+9\%_{\circ}$ sea water did not show-changes of potential drop. However, those formed on lead and copper were reasonable electrodes. It was concluded that cathodic reactivities of proton through the anodic film in aqueous solution were constant without regard to the kinds of metals used with anodic film electrode at operated current density ranges, because the values of transition time obtained in 0.5M sodium chloride solution and $9\%_{\circ}$ sea water nearly coincided. The values of transition time of the first step by the galvanostatic method were obtained from 0.22 to 1.40 sec ranges far less than one minute. Therefore, it suggested that cathodic reactions of proton through the anodic film were mainly controlled by diffusion/adsorption process. The differences of between $\tau_{1}/4$ in $9\%_{\circ}$ sea water and $\tau_{1}/4$ in 60mM $DBNA+9\%_{\circ}$ sea water, and between $E_{1}/4$ in sea water and $E_{1}/4$ in 60mM $DBNA+9\%_{\circ}$ sea water at the constant current density with $1.9\times10^{-4}\sim5.0{\times}10^{-6}\;amp/cm^2$ were 0.06 sec and 0.53 v. respectively and cathodic reactions of DBNA on the anodic film electrodes were chiefly controlled by adsorption/diffusion process. The reason that adsorption quantities of proton on anodic film formed on aluminum and zinc in aqueous solutions were much more than those on lead and copper, seems to lie due mostly to the number of porosity produced on anodic film used.

  • PDF