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        검색결과 607

        66.
        2021.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        A 19-year-old male Siberian tiger was presented with inappetence and paralysis of hind limbs. In a computed tomography (CT) scan, intervertebral disk disease at L3–L4 was detected. Cardiac arrest occurred during the surgery. At autopsy, myxomatous mitral valve degeneration (MMVD) and eccentric hypertrophy of the left heart were noted. The diagnosis was congestive heart failure caused by MMVD. Microscopically, myocardial and pulmonary fibrosis were observed in addition to the disintegration of the fibrosa layer and accumulation of glycosaminoglycans and proteoglycans in the spongiosa layer of the mitral valve. This is the first case of congestive heart failure with MMVD in a Siberian tiger.
        4,000원
        67.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Smart factories can be defined as intelligent factories that produce products through IoT-based data. In order to build and operate a smart factory, various new technologies such as CPS, IoT, Big Data, and AI are to be introduced and utilized, while the implementation of a MES system that accurately and quickly collects equipment data and production performance is as important as those new technologies. First of all, it is very essential to build a smart factory appropriate to the current status of the company. In this study, what are the essential prerequisite factors for successfully implementing a smart factory was investigated. A case study has been carried out to illustrate the effect of implementing ERP and MES, and to examine the extensibilities into a smart factory. ERP and MES as an integrated manufacturing information system do not imply a smart factory, however, it has been confirmed that ERP and MES are necessary conditions among many factors for developing into a smart factory. Therefore, the stepwise implementation of intelligent MES through the expansion of MES function was suggested. An intelligent MES that is capable of making various decisions has been investigated as a prototyping system by applying data mining techniques and big data analysis. In the end, in order for small and medium enterprises to implement a low-cost, high-efficiency smart factory, the level and goal of the smart factory must be clearly defined, and the transition to ERP and MES-based intelligent factories could be a potential alternative.
        4,800원
        68.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        유방조직 확장기(BTE)는 MR 금기로 분류되고 있으나 이전 연구들에서 제한적인 조건에서 MRI 검사가 가능함을 발표하였다. 본 연구는 미국재료시험 협회에서 권고하는 변위력과 토크뿐 만 아니라 뒤틀림을 측정하여 MR 안전성을 평가하였다. 3.0 T MRI 장치와 350 ㎖, 650 ㎖ BTE를 사용하였다. 변위력은 자기장이 가장 큰 지점에서 측정 기구에 BTE를 매달고 발생된 최대 변위각을 3회씩 측정하였다. 토크는 원형 용기에 생리식염수를 단계적으로 채운 BTE를 놓고 자기장에 의해 발생된 회전력을 45˚ 간격에서 정성적으로 측정하였다. 뒤틀림은 생리식염수를 최대로 채운 뒤 자성 밸브의 뒤틀림 각도를 포켓 경사계를 이용하여 두부, 어깨, 유방, 간, 골반이 중심일 때 유방 위치에서 각각 측정하였다. 측정 결과 변위각 은 350 ㎖의 경우 0 ㏄, 150 ㏄에서 각각 125˚, 54.3˚, 650 ㎖은 0 ㏄에서만 123.3˚로 MR 금기 기준을 초과했다. 토크는 350 ㎖의 경우 모두 +4로 측정되었고, 650 ㎖의 경우 450 ㏄ 생리식염수 미만에서는 모두 +4, 550 ㏄ 이상에서는 +1∼+4로 나타났으며, 일부를 조건을 제외하고 모두 MR 금기 조건을 초과했다. 뒤틀림은 350 ㎖의 경우 5˚∼80˚ 를 나타냈으며. 650 ㎖는 15˚∼90˚를 나타내어 환자에게 통증 유발 가능성을 확인했다. BTE의 변위각, 토크, 뒤틀림을 측정하여 MR 금기로 평가하였으며, 어떠한 조건하에서도 MR 환경에서 환자의 안전을 보장할 수 없다.
        4,000원
        70.
        2021.05 구독 인증기관 무료, 개인회원 유료
        RAM represents reliability, availability, and maintenance, and is a key performance indicator that is utilized throughout the life cycle of the weapon system from the stage of requesting to disposal. If the RAM target value is set to a too high value, development may be delayed or development cost may be increased. If it is set to a too low value, frequent failures may occur during training, or a problem may arise that the number of available weapon systems is insufficient. The currently most used method to set the RAM target value is to write an operation mode summary and calculate it through an equation. However, as the definition of the operation mode is not standardized, different RAM target values may be set depending on the authoring organization. This study aims to analyze the current situation and suggest an alternative to this problem.
        4,000원
        71.
        2021.05 구독 인증기관 무료, 개인회원 유료
        When considering military operations that require rapid response time, forward supply operation of various type of ammunition is essential. Also, t is necessary to supply ammunition in a timely manner before an ammunition shortage situation occurs. In this study, we propose a mathematical model for allocation of ammunition to ammunition storehouse at the Ammunition Supply Post (ASP). The model has several objectives. First, it ensures that the frequent used ammunition is stored in a distributed manner at a high workability ammunition storehouses. Second, infrequent used ammunition is required to be stored intensively at a single storehouse as much as possible. Third, capacity of the storehouse and compatible storage restriction required to be obeyed. Lastly, criticality of ammunition should be considered to ensure safety distance. We propose an algorithm to find the pareto-based optimal solution using the mathematical model in a reasonable computation time. The computational results show that the suggested model and algorithm can solve the real operational scale of the allocation problem.
        4,000원
        73.
        2021.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A safety assessment of radioactive waste repositories is a mandatory requirement process because there are possible radiological hazards owing to radionuclide migration from radioactive waste to the biosphere. For a reliable safety assessment, it is important to establish a parameter database that reflects the site-specific characteristics of the disposal facility and repository site. From this perspective, solubility, a major geochemical parameter, has been chosen as an important parameter for modeling the migration behavior of radionuclides. The solubilities were derived for Am, Ni, Tc, and U, which were major radionuclides in this study, and on-site groundwater data reflecting the operational conditions of the Gyeongju low and intermediate level radioactive waste (LILW) repository were applied to reflect the site-specific characteristics. The radiation dose was derived by applying the solubility and radionuclide inventory data to the RESRAD-OFFSITE code, and sensitivity analysis of the dose according to the solubility variation was performed. As a result, owing to the low amount of radionuclide inventory, the dose variation was insignificant. The derived solubility can be used as the main input data for the safety assessment of the Gyeongju LILW repository in the future.
        4,000원
        74.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 다양한 항생제 내성을 갖는 Salmonella enterica subsp. enterica serovar Typhimurium ATCC 19585 (STWT), S. Typhimurium KCCM 40253 (STKCCM), ciprofloxacininduced S. Typhimurium ATCC 19585 strains (STCIP), and S. Typhimurium CCARM 8009 (STCCARM)에 대한 phage의 흡착 및 용균 특성을 평가하였다. PBST-10, PBST-13, PBST-32, PBST-35, P-22, P-22 B1 phages는 narrow host range를 보였다. 숙주인 STWT, STKCCM, STCIP에 대한 phage 의 흡착률은 각각 47-85%, 58-95%, 61-93%였지만, STCCARM 에 대한 phage의 흡착률은 14-36%의 낮은 수준을 보였다. STWT, STKCCM, STCIP, STCCARM에 대한 phage burst size는 각 각 43-350, 37-530, 66-500, 24-500 plaque-forming unit (PFU)으로 다양하게 관찰되었다. P-22 B1을 제외한 모든 phage는 배양 초기에 STCIP숙주를 효과적으로 저해하였다. 이러한 결과는 항생제 내성균을 저해하기 위해 phage control system 개발에 유용한 정보로 활용될 것이다.
        4,000원
        75.
        2020.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We determine the observing sites for eclipses of large magnitude recorded in ancient Chinese chronicles from 200 BCE to 900 CE, by adopting the difference between terrestrial time and universal time, ΔT, given by Morrison & Stephenson (2004). The records of solar eclipses with large magnitude are divided into four groups in accordance with the historical variations of the capital cities of ancient Chinese dynasties. We determine areas in which all the eclipses in each group, with an eclipse magnitude larger than a certain threshold value, could be observed. We fi nd that these areas coincide with the historical capitals, which agrees with the general idea that the solar eclipses were observed at the capital of each dynasty. This result also veri es the ΔT values during the period from 100 BCE to 400 CE, during which historical records of eclipses are so rare that the ΔT values can only be obtained by interpolating the long-term data. Moreover, we show that the eclipses described by the term Ji in East-Asian history are not all total eclipses; their mean magnitude is 0:96 ± 0:04. We fi nd that complementary expressions, such as dark daytime and appearance of stars during the eclipse, strengthen the possibility that eclipses described by the term Ji were total. We also provide quantitative definitions for expressions such as `being not complete and like a hook', `being almost complete', `visibility of stars during the eclipse', and `darkness during an eclipse.' The literal meanings of these expressions are in agreement with the recent physical modeling of sky brightness during total eclipses provided by K¨onnen & Hinz (2008).
        4,600원
        76.
        2020.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        We report a massive outbreak of human Q fever cases, which occurred at totally 11 humans. The occurrence was related to a goat farm where Coxiella burnetii infection was diagnosed from goat tissues and environmental specimens. From January of 2018, continuous abortions from 6 goats occurred. Laboratory tests from 77 goat specimens for C. burnetii showed that 54 (70.1%) and 63 (81.8%) goats were positive by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. The infection was also confirmed from the farmer, his wife and 9 persons from all 16 veterinary officials who had visited the farm for protective measures and preparing goat specimens for laboratory tests. The farm was found to be extensively contaminated with C. burnetii from the examination to the environmental specimens and epidemiological inspections, which might be the main source of C. burnetii infection to humans. The extensive contamination to the farm was derived from the uncareful handling of postpartum animal tissues or discharges by the farm owner. This report will contribute to the establishment of educational system on the biosecurity to novice farmers.
        4,000원
        79.
        2020.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Forward head posture (FHP) is common postural malalignment. FHP is described relatively extension to upper cervical and lower cervical is relatively flexion. Although several researchers mentioned the lower cervical flexion posture in FHP, most of the studies related to FHP is focused on the deep cervical flexor function. Objects: The purposes of present study is to compare the cervical strength (upper cervical extension [UCE], lower cervical extension [LCE], upper cervical flexion [UCF], lower cervical flexion [LCF]) between individuals with and without FHP. Methods: Fifty-one participants are recruited. Participants who have the craniovertebral angle (CVA) less than 48 degree were classified to the FHP group (n = 24) and the others were included in without FHP group (n = 27). The cervical strength (UCE, LCE, UCF, LCF) were measured using Smart KEMA strength sensor and the strength data was normalized by body weight. All strength measurement conducted at head and neck neutral position in sitting. Independent t-test was used to compare the cervical strength between individuals with and without FHP. Results: The mean value of CVA was greater in without FHP group than with FHP group (p < 0.000). The strength value of UCF (p < 0.002) and LCE (p < 0.001) was significant less in FHP group than without FHP group. But no significant differences were seen in the LCF and UCE strength between two groups. Conclusion: UCF and LCE weakness in FHP group should be considered to evaluate and manage the individuals with FHP.
        4,000원
        80.
        2020.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Site characterization for decommissioning Kori Unit 1 is ongoing in South Korea after 40 years of successful operation. Kori Unit 1’s containment building is assumed to be mostly radioactively contaminated, and therefore radiation exposure management and detailed contamination investigation are required for decommissioning and dismantling it safely. In this study, site-specific Derived Concentration Guideline Levels (DCGLs) were derived using the residual radioactivity risk evaluation tool, RESRAD-BUILD code. A conceptual model of containment building for Kori Unit 1 was set up and limited occupational worker building inspection scenario was applied. Depending on the source location, the maximum contribution source and exposure pathway of each radionuclide were analyzed. The contribution of radionuclides to dose and exposure pathways, by source location, is expected to serve as basic data in the assessment criteria of survey areas and classification of impact areas during further decommissioning and decontamination of sites.
        4,000원
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