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        검색결과 105

        1.
        2023.11 구독 인증기관·개인회원 무료
        The mobility of uranium (U) in various disposal environments of a deep geological repository is controlled by various geochemical conditions and parameters. In particular, oxidation state of uranium is considered as a major factor to control the mobility of uranium in most of geological environments. In this study, therefore, we investigated the geochemical behaviors of uranium in grounwater samples from natural analogue study sites located in the Ogcheon Metamorphic Belt (OMB). Groundwater samples were taken using a packer system from Boeun Hoenam-myun site and Geumsan Suyoung-ri site where several boreholes were dilled with various depths. The geochemical properties and parameters such as temperature, pH, Eh, EC, and DO were directly measured in the site using an in-line measurement method. The concentrations of major cations and anions in the groundwater samples were measured by using ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry) and IC (Ion Chromatography), respectively. The concentrations of trace elements including U and Th were measured by using ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) The concentrations of U in the groundwater samples are very low for the Hoenammyun site (0.03~0.69 ppb) and Suyoung-ro site (0.39~1.74 ppb) even though the two sites are uranium deposits and redox conditions are weakly oxidizing. The speciation, saturation index (SI), pH-Eh (Poubaix) diagram were calculated using the Geochemist’s Workbench (GWB 9.0) program and the recent OECD/NEA thermochemical database for U. Calculation results for U speciation in the groundwater samples show that major dissolved uranium species in the groundwater samples are mainly as calcium uranyl carbonate complexes such as Ca2UO2(CO3)3(aq) and CaUO2(CO3)3 2- for almost all groundwater samples. The calculated results for SI and Poubaix diagram also show that the dominant uranium solid phase is a uranyl silicate mineral, uranophane (Ca(H2O)(UVIO2)2 (SiO2)2(OH)6), not uraninite (UIVO2). Since the determination of Eh values for natural groundwater samples is very difficult and uncertain work, we analyzed and discussed the effect of Eh on the geochemical behaviors of U in the groundwater. However, these calculation results are not consistent with the observation for U minerals in rock samples using electron microscopic techniques. Thus, we need further studies to explain the discrepancy between calculation and observation results.
        3.
        2023.07 구독 인증기관 무료, 개인회원 유료
        The Belt and Road Initiative (BRI) is one of the bridges to the globalization of trade. The BRI will achieve all its goals and help each participant nation's economy flourish. Expanding international commerce and reducing inequality among participating nations are indicators of stronger economic growth. This study intends to investigate how the Belt and Road Initiative affects global trade and equality among its participants and elaborate the people perception on BRI in Indonesia and Malaysia. This study uses secondary data to compare the BRI members, while the original data was collected using a survey approach. The four factors evaluated in secondary data are globalization, international trade, equality, and business environment. K-mean cluster, One-way ANOVA, and Partial Least Squares were used for data analysis. The survey is conducted in English on two platforms (online and offline), they are analyzed by Homogeneity of Variances test. The findings indicated foreign debt, political stability, level of corruption, education index, and life expectancy are the differences in the business environments that account for this. If the member nations in the Belt and Road Initiative have favorable conditions in terms of political stability, education, and life expectancy, they will succeed in terms of globalization, international trade, and equality. In addition, the nation should have little foreign debt and less corruption. The last, both Malaysia and Indonesia have positive perception on the BRI and support the country to participate on it.
        4,000원
        4.
        2023.05 구독 인증기관·개인회원 무료
        The mobility of uranium (U) in the environment of a deep geological repository is controlled by various geochemical conditions and parameters. In particular, oxidation state of uranium is considered as a major factor to control the mobility of uranium in most of geological environments. In this study, therefore, we investigated the mobility of uranium in a deep geological repository by a natural analogue approach using a uranium deposit in the Ogcheon Metamorphic Belt (OMB). Uranium contents of rock samples from the study site ranged from 1.3 to 71 ppm (average 17.4 ppm). Uranium minerals found in the study site were mostly uraninite (UIVO2+x) and uranothorite ((UIV, Th)SiO4). The concentrations of U in the groundwater samples were very low (0.025~0.690 ppb) even though redox conditions are weakly oxidizing. Calculation results for U speciation in groundwater samples showed that major dissolved uranium species in the groundwater samples are mainly as calcium uranyl (UO2 2+) carbonate complexes such as Ca2UO2(CO3)3(aq) and CaUO2(CO3)3 2-. However, the activity ratios between 234U and 238U (AR(234U/238U)) showed U behavior in reducing conditions although the groundwater conditions were not reducing conditions and major dissolved U species were U(VI) species. Results from electron microscopic analyses for rock samples showed that major uranium minerals were U(IV) minerals such as uraninite and uranothorite. We could not identify other uranyl minerals and altered minerals from uraninite. This means that the geochemical condition of the study site has been maintained a reducing condition although the groundwater condition was a weakly oxidizing condition. Thus, the dissolution of uranium is strongly limited by the low solubility of uraninite. It is not obvious how the reducing condition of the study site has been maintained. Reducing agents such as pyrite, organic materials, and reducing bacteria might contribute to maintaining the reducing condition although further studies will be necessary. Results from this study imply that uranium mobility will be greatly limited by low dissolution of uraninite into groundwater if the reducing condition is well reserved. This limited mobility of uranium will be also contributed by low possibility of uraninite alteration into uranyl minerals which have a higher solubility than uraninite.
        5.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Submarining is a phenomenon in that the lap belt goes over the pelvis of the occupant during a frontal crash. It is known to be one of the causes of serious abdominal injuries for the belted occupant. The goal of the current study was to investigate the effect of both the belt geometry and dummy variations on the occurrence of submarining. A series of quasi-static belt-pull tests were performed to evaluate the influence of the parameters on the occurrence of the submarining. The main influencing factor of the submarining was the lap belt angle. The tear or wrinkle of the dummy clothing and torso angle relative to the pelvis also affected the propensity of the submarining. Therefore, these parameters need to be closely monitored to obtain repeatable test results.
        4,000원
        6.
        2022.10 구독 인증기관·개인회원 무료
        In south Korea, most of uranium deposits are distributed in the Ogcheon belt, which is one of two late Precambrian to Paleozoic fold belts (the Imjingang and Ogcheon belts). A study site of the Ogcheon metamorphic belt (OMB) in Hoenam-myun, Boeun-gun was selected for the natural analogue study by preliminary site investigation for several candidate study sites. Three boreholes were drilled in the site and some rock cores and groundwater samples were taken from the boreholes. Various analytical studies for the samples are now being performed. Thus, in this study, various basic characteristics of the study site such as occurrence, geological, mineralogical, and chemical properties were investigated for a future study. Base rocks containing uranium in the OMB are usually black slate and coaly slate. Coaly slate usually shows a higher content of uranium and larger grain size of uranium than black slate. Uranium minerals found in the OMB are uraninite, uranothorite, brannerite, ekanite, coffinite, francevillite, uranophane, autunite, and torbernite depending on the base rock types. Uranothorite is abundant in black slate whereas uraninite is mostly abundant in coaly slate. Chemical compositions of the solid and groundwater samples from the study site were also analyzed by using ICP-MS/OES (Inductively Coupled Plasma Mass Spectrometry) and XRF (X-ray Fluorescence). This will contribute to determine uranium minerals in the solid samples and uranium speciation in the groundwater. The results of this study will contribute to performing future natural analogue studies in domestic uranium deposits and provide basic information and knowledge for understanding long-term geochemical behaviors of radionuclides in a high-level radioactive repository.
        7.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, due to the rapid increase in vehicle accidents, research on improving seat belts and restraint system are being actively on going to solve the problems in vehicle for passengers. The characteristics of lap belt load and pelvic displacement were simulated through MADYMO program using Hybrid III 50th percentile male dummy to analyze the submarining by changing the collision speed and seat back angle by applying the forward collision pulse form accident scenario. As a result, the submarining occurred when the seat-back angle was 60° or higher at the collision speed of 50km/h or higher. Lastly, using the characteristics of the lap belt load and pelvic displacement when the anti-submarining belt (ANSB) system adapted, the pelvic displacement was reduced as well as submarining.
        4,000원
        8.
        2022.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Bangladesh enjoys an advantageous geographical position. It has been a transit station for businessmen from South Asia, Southeast Asia, Central Asia and even Europe since ancient times. It is located at the intersection of China Economic Circle, South Asia Economic Circle and ASEAN Economic Circle, and is an important country along the belt and road initiative. The “Belt and Road” initiative was supported by Bangladeshi Prime Minister Sheikh Hasina. Since the “Belt and Road” initiative was put forward, China and Bangladesh have achieved remarkable results in policy communication, facility connectivity, smooth trade, capital financing and people-to-people communication. However, China and Bangladesh still face challenges in the political, security, economic and social fields to jointly build the “Belt and Road” initiative. In the new period, China and Bangladesh should strengthen political communication, promote the docking of China-Bangladesh development strategies, strengthen facility connectivity and industrial cooperation, promote cultural exchanges, promote the upgrading of cooperation between the two countries, and jointly build a high-quality “Belt and Road” initiative.
        7,800원
        9.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The global economy has been hit hard by the COVID-19 pandemic, and countries around the world urgently need to restore economic growth. As countries in Eurasia become more and more closely connected, it is inevitable for China's Belt and Road Initiative and South Korea's new Northern policy to connect. In this context, what matters is the connection of the railway network. The purpose of this study is to analyze the impact of the integration of the Korean Terminal Railway (TKR) into the Eurasian railway network by connecting the Korean Terminal Railway (TKR) with China's China-Europe freight trains. The results show that there is an interactive positive correlation between railway freight volume and GDP, and South Korea is expected to become the logistics center of East Asia and improve its status and influence in the world center. Within the Korean peninsula, the railway connection can draw North Korea into a larger multilateral agreement system, and South Korea can use external forces within the system to push North Korea to seek more economic cooperation and actively promote the reunification process. The economic development of Northeast Asia also plays a positive role in the economic recovery of the three provinces in northeast China.
        4,300원
        10.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to find out the management and sanitation status of protective gear provided at the construction site, a case study and survey were conducted by visiting the site. As a result of the case study, inspection and management, disinfection, and storage of protective equipment were insufficient in both workplaces with less than 50 employees and workplaces with more than 100 employees. As a result of the survey, workers(66.2%), said they did not know how to identify hard hats(67.6.%), how to identify bad hard hats(60.8%), and how to identify bad safety belts (73.0%), even though workers(66.2%) were educated on protective gear, and those in charge of protective gear Non-specified(56.8%), regular inspection of the provided protective equipment was not performed(82.4%), and disinfection was not performed(90.5%). Therefore, as a management plan to maintain the performance of personal protective equipment, educational aspects, regular training on protective equipment, training on how to identify defective protective equipment, management of recording papers, technical aspects, strengthening of standards for placement of dedicated safety managers in small workplaces, participation of workers’ representatives when selecting protective equipment, and selection of protective equipment for workers Providing opportunities, administrative aspects of protective equipment regulation and management, introduction of sanitary and cleanliness system, and selection of personnel in charge of protective equipment management were suggested.
        4,000원
        11.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        요즘은 건강을 위한 스마트 헬스 케어 웨어러블의 개발이 가속화되는 시대이다. 그 중 활발한 연구 분야 중 하나인 EMS 전기자극을 활용한 웨어러블 제품이 많이 출시되었다. 하지만 연구되거나 출시되어있는 EMS 웨어러블은 근육의 세분화에 집중하지 못한 포괄적인 전신 슈트나 복부 전체를 덮는 벨트 형식으로 출시되어있다. 이에 본 연구에서는 특정 근육을 세분화시킨 EMS 패턴을 적용하고 복압 벨트에 호흡을 측정할 수 있는 스트레치 센서를 부착하여 두 가지 호흡법을 활용해 연구를 진행하고자 한다. 측정방법은 들숨과 날숨으로 실험을 진행하며 대상자는 건강한 신체의 20대 남성 10명을 대상으로 진행했다. 본 연구의 결과 흉식호흡과 복식호흡 모두 센서의 민감도는 5mm, 3mm, 기본 센서 순으로 센서별 순위 결과를 확인할 수 있었고 EMS 복압 벨트를 통해 전기자극을 적용 전, 후로 나누었을 때전기자극을 적용한 후 호흡의 활성화가 향상되었음을 알 수 있었다. 연구의 결론은 2가지 호흡법을 신체 기능적 근거로 제작한 2가지 패턴으로 인해 호흡법에 적합한 전기자극을 적용 시 적용하지 않았을 때 보다 3가지 센서로 호흡 활성화 효과와 센서 간 민감도 차이를 확인할 수 있었다. 본 연구 결과를 기반으로 후속 연구에서는 EMS 패턴과 스트레치 센서가 통합된 의복형 웨어러블 제품에 실시간 모니터링이 가능한 호흡 스마트 의류를 개발하고자 한다.
        4,000원
        12.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        자그로스 습곡대는 신생대 시기에 아라비아 판과 유라시아 판이 충돌하며 형성되었다. 이 습곡대는 터키에서 호르므즈 지역까지 북서-남동 방향으로 2,000 km 이어진 산맥을 이룬다. 전세계 석유의 약 8%가 자그로스 산맥(충상단 층)의 전면부에 발달한 습곡으로 이루어진 배사구조에 집적되어 있다. 지금까지 알려진 자그로스 지역의 5개 석유시스템 가운데 백악기 중기-마이오세 초기 석유 시스템의 원시 자원량이 가장 많다. 백악기 중기-마이오세 초기 석유 시스템의 근원암은 Kazhdumi층과 Pabdeh층으로 석유 생성 이상으로 숙성되었으며, 저류암은 Bangestan층군(Sarvak, Ilam 층)과 Asmari층이며, 덮개암은 증발잔류암층인 Gachsaran층과 셰일층인 Gurpi층이다. Bangestan층군과 Asmari층에 트랩되어 있는 원유는 90%이상이 Kazhdumi층에서 기원하였고 그 외 나머지 원유는 Pabdeh층에서 기원하였다. 데즈풀만 지역에서 고각의 배사구조를 이루고 있는 Asmari, Sarvak, Khami층은 이미 많은 부분이 탐사된 반면 좀더 깊은 곳에 위치한 퇴적층과 저각의 소규모 배사구조는 아직 탐사되지 않았다. 그러므로 이 지역의 개발 잠재력은 자그로스 습 곡대 석유시스템의 이해를 필요로 한다.
        4,900원
        14.
        2021.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To improve the shortcomings and expand the advantages of the single-roll melt drag method, which is a type of continuous strip casting method, the melt drag method with a molding belt is applied to AZ31 magnesium alloy. By attaching the forming belt to the melt drag method, the cooling condition of the thin plate is improved, making it possible to manufacture thin plates even at high roll speed of 100 m/min or more. In addition, it is very effective for continuous production of thin plates to suppress oxidation of the molten metal on the roll contact surface by selecting the protective gas. As a result of investigating the relationship between the contact time between the molten metal and the roll and the thickness of the sheet, it is possible to estimate the thickness of the sheet from the experimental conditions. The relationship between the thin plate thickness and the grain size is one in which the thinner the thin plate is, the faster the cooling rate of the thin plate is, resulting in finer grain size. The contact state between the molten metal and the roll greatly affects the grain size, and the minimum average grain size is 72 μm. The thin plate produced using this experimental equipment can be rolled, and the rolled sample has no large cracks. The tensile test results show a tensile strength of 303 MPa.
        4,000원
        16.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        port is the intersection of highway, railway, waterway and other transportation modes, and is the key to realizing integrated transportation. There are many excellent ports around the Tumen River Region. With the obvious location advantages, Tumen River Region is an important part of Tumen River regional cooperation and development, and is the key to realizing the “borrow port to sea”, which is raised in “China Tumen River regional cooperation and development planning outline -- regard Changjitu area as the development and opening leading area” (referred to as “planning outline”). This paper focus on the main ports in the Tumen River region, taking them as the research object. Furthermore, the paper makes the strategic plan for the port cluster in the Tumen River region as well as puts a collaboration scheme is proposed by analyzing the research reviews of the Tumen River region and the present situations of the main ports.
        4,000원
        17.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 논문은 중국의 일대일로 (Belt and Road Initiative)가 아세안 국가들에게 확산되어 중국이 이 지역에서 지배적인 세력이 될 것인가 하는 질문을 던진다. 이 문제를 탐구하기 위해 아세안 국가 지도자들의 대중국 접근과 정치적 동학, 그리고 중국의 정치군사적 세력 확대에 대한 견제라는 두 변수를 중심으로 분석할 것을 제안한다. 이 두 변수를 중심으로 분석할 때 아세안 국가의 일대일로는 중국 일방적으로 추진되는 것으로 단순화 시킬 수 없다는 것을 알 수 있다. 첫째, 아세안 개별국가 정치지도자들이 자국 경제발전의 필요와 정치적 동학에 따라 일대일로의 구체적 사업들을 받아들이고 조정하는 경우가 빈번하다. 둘째, 아세안 국가들은 중국과 경제교류를 지속하지만 동시에 정치적, 군사적으로 중국의 영향력 하에 지배되는 것을 거부하고 견제한다. 이와 같이 경제적 실리를 추구 하면서 동시에 중국의 세력 확대를 견제하는 전략을 헤징 (hedging)전략으로 설명한다. 실제 일대일로 케이스로 친중적인 미얀마와 말레이시아를 들어 이 나라 들에서 정치적 변화에 따라 일대일로 사업이 취소되고 재조정된 경우들을 살펴 본다. 이 두 나라를 비롯하여 아세안 국가들은 대부분 경제발전의 필요상 경제적으로 중국과 협력을 유지하지만 중국의 정치군사적 세력 확대로 자국이 위협 받는 것을 견제한다. 이것은 국가에 따라 차이는 있지만 헤징전략으로 설명할 수 있다. 즉, 헤징의 개념으로 설명하면, ‘경제적 실용주의’로 경제협력을 추진하며, 다른 한편 정치군사적으로는 중국을 견제하여 다른 인도-태평양 국가들과 협력하는 ‘간접적 밸런싱’의 전략을 취한다는 것이다. 아세안은 중국의 지배적 영향 하에 들어가기를 원치 않으며 ‘아세안 중심성’을 유지하려 할 것이다.
        8,400원
        18.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bilateral profound friendship between China and Pakistan and the "all-weather strategic partnership" have given great support to mutual cooperation. China and Pakistan are moving forward to the goal of "economic corridor construction as the center, Gwadar port, transport infrastructure, energy and industrial cooperation as the points to form the ‘1+4’ economic cooperation and common development". However, the relationship between the two countries is also facing some challenges in the process of sustainable development, among which the populist in Pakistan is gradually emerging. If left unchecked, it may lead to a great threat to CPEC and other cooperation. Therefore, strengthening basic research on populism in Pakistan is of great significance for enhancing the all-weather strategic cooperative partnership and ensuring the smooth implementation of the CPEC. After reviewing the current research status and deficiencies of populism theory, this paper analyzes populism from the dimensions of social classes, religions and regions, so as to deeply understand the breeding source of populism. From the perspective of class, populism in Pakistan has distinct characteristics of class antagonism. From a religious perspective, there is a deeply rooted political psychology among the Pakistani people. From a regional perspective, the traditional social structure of Islam in Pakistan determines that the loyalty of individuals to religion, family and a smaller region is greater than the loyalty to the nation state.
        5,800원
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