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        검색결과 226

        1.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since rice is the main food in Korea, there are no regulations on corn milling yet. Corn is known as one of the world's top three food crops along with wheat and rice, and it is known that 3.5 billion people worldwide use corn for food. In addition, corn mills are not developed or sold in Korea, but the use of corn mills is increasing significantly in many countries in Southeast Asia. In the Philippines, as Korea's rice mill import increases, Korea's KAMICO (Korea Agricultural Machinery Industry Cooperative) and domestic company A agreed to develop a corn mill jointly with PHilMech, an organization affiliated with the Philippine Ministry of Agriculture. However, research on corn milling was very insignificant, so the development was carried out based on the technology of Korea's rice mill. Rice milling is performed by peeling off the skin of rice and producing brown or white rice, so it is carried out by removing the skin and cutting the skin. On the other hand, in the corn mill, the skin of the corn is peeled, pulverized and selected to produce main products suitable for edible use. Therefore, in order to develop a corn mill, processes such as peeling, transfer, grinding, sorting, and by-product separation are required, and suitable parts must be developed. In addition, the performance must be gradually improved through experiments in which corn is repeatedly milled. The Philippines produces 7.98 million tons/year of corn, which is about 100 times that of Korea, and is mostly consumed as a staple food. This is about 10% of the total crop production in the Philippines. In addition, the main cultivation complexes of corn are the mountainous regions of Tarlac or Pangasinan, and the produced corn is 72.4% of the so-called yellow corn called Arabel and Sarangani, and the remaining 27.6% are known as white corn. In this study, it was intended to produce grains of 2.5 mm or less suitable for food for yellow corn and to develop a corn mill for 200 kg per hour. Detailed conditions for development are stipulated as more than 55% of the main product recovery rate, more than 31% of the by-product recovery rate, less than 5% of the raw material loss rate, and more than 80% of the embryo dislocation rate. In this study, to achieve this, the overall process of the corn mill was developed, and the optimal conditions for the corn mill were obtained through the development of parts and empirical tests to improve performance. In addition, it was intended to achieve the development goal by evaluating and analyzing the performance of each part so that it did not conflict.
        4,800원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        가상의 공간에서 함께 즐기는 콘텐츠에 대해 관심이 늘어나고 있다. 더불어 가상공간에서 나만의 아바타도 꾸미고 게임 콘텐츠 역시 즐기고 있다. 이러한 가상의 공간을 메타버스라고 하며 대표적인 플랫폼으로는 제 페토와 로블록스가 있다. 메타버스 플랫폼은 플랫폼의 취지에 맞게 유저가 직접 제작하기 편리한 컨텐츠 제 작 도구를 지원한다. 그러나 일반 유저가 제작한 콘텐츠는 메타버스에서 활동하고 있는 다양한 유저의 관심 과 흥미를 지속적으로 유발하기에는 부족한 부분이 있어 꾸준한 흥행이 어렵다. 본 논문은 기존 게임 엔진을 활용해서 콘텐츠를 제작하는 콘텐츠 개발자로서 메타버스 플랫폼이 제공하는 제작 도구의 효용성을 검증하 고자 게임 엔진의 선택 기준을 참고하여 인터페이스, 개발 언어, 개발 공정의 기준으로 대표하는 플랫폼의 제작 도구를 비교하였다.
        4,000원
        3.
        2023.11 구독 인증기관·개인회원 무료
        One of the important components of a nuclear fuel cycle facility is a hot cell. Hot cells are engineered robust structures and barriers, which are used to handle radioactive materials and to keep workers, public, and the environment safe from radioactive materials. To provide a confinement function for these hot cells, it is necessary to maintain the soundness of the physical structure, but also to maintain the negative pressure inside the hot cell using the operation of the heating, ventilation, and air conditioning (HVAC) systems. The negative pressure inside the hot cells allows air to enter from outside hot cells and limits the leakage of any contaminant or radioactive material within the hot cell to the outside. Thus, the HVAC system is one of the major components for maintaining this negative pressure in the hot cell. However, as the facility ages, all the components of the hot cell HVAC system are also subject to age-related deterioration, which can cause an unexpected failure of some parts. The abnormal operating condition from the failure results in the increase of facility downtime and the decrease in operating efficiency. Although some major parts are considered and constructed in redundancy and diversity aspects, an unexpected failure and abnormal operating condition could result in reduction of public acceptance and reliability to the facility. With the advent of the 4th Industrial Revolution, prognostics and health management (PHM) technology is advancing at a rapid pace. Korea Hydro & Nuclear Power, Siemens, and other companies have already developed technologies to constantly monitor the integrity of power plants and are applying the technology in the form of digital twins for efficiency and safety of their facility operation. The main point of PHM, based on this study, is to monitor changes and variations of soundness and safety of the operation and equipment to analyze current conditions and to ultimately predict the precursors of unexpected failures in advance. Through PHM, it would be possible to establish a maintenance plan before the failure occurs and to perform predictive maintenance rather than corrective maintenance after failures of any component. Therefore, it is of importance to select appropriate diagnostic techniques to monitor and to diagnose the condition of major components using the constant examination and investigation of the PHM technology. In this study, diagnostic techniques are investigated for monitoring of HVAC and discussed for application of PHM into nuclear fuel cycle facilities with hot cells.
        4.
        2023.11 구독 인증기관·개인회원 무료
        The thermal treatment of radioactive waste attracts great attention. The thermal treatment offers lots of advantages, such as significant volume reduction, hazard reduction, increase of disposal safety, etc. There are various thermal technologies to waste. The developed technologies are calcination, incineration, melting, molten salt oxidation, plasma, pyrolysis, synroc, vitrification, etc. The off-gas treatment system is widely applied in the technologies to increase the safety and operation efficiency. The thermal treatment generates various by-product and pollutants during the process. The dust or fly ash are generated as a particulate from almost every radioactive waste. The treatment of PVC related components generates hydrogen chloride, which usually brings corrosion of facility. The treatment of rubber and spent resin generates sulfur oxide, SOx. The treatment of nitrile rubber generates nitrogen oxide, NOx. The incomplete combustion of radioactive waste usually generates carbon oxide, COx. The process temperature also affects the generation of off gas, such as NOx and/or COx. Various off gas treatment components are organized for the proper treatment of the previously mentioned materials. In this study systematical review on off gas treatment will be reported. Also, worldwide experiences and developed facility will be reported.
        5.
        2023.11 구독 인증기관·개인회원 무료
        The primary purpose of high temperature process of radioactive waste is to satisfy the waste acceptance criteria and volume reduction. The WAC offers the guideline of waste form fabrication process. The WAC is defined as quantitative or qualitative criteria specified by the regulatory body, or specified by and operator and approved by the regulatory body, for radioactive waste to be accepted by the operator of a repository for disposal, or by the operator of a storage facility for storage. The main objective of WAC is to protect staff and general public and environment by the containment of radioactive material, limit external radiation level, and prevent criticality. The WAC also offers systematic management of radioactive waste by standardization of waste management operations, facilitation waste tracking, ensure safe and effective operation of operating facilities, etc. Since the high temperature process for radioactive waste is considered in many countries, lots of codes and standards are considered. In many WACs, compressive strength, thermal cycle stability, radiation exposure stability, free liquid, and leachability are evaluation to understand the effect of solidified form to the disposal facility. In this paper, systematical review on waste form will be discussed. In addition, brief result of characterization of waste form will be compared.
        6.
        2023.11 구독 인증기관·개인회원 무료
        During the operation of nuclear power plant (NPP), the concentrates and spent resin are generated. They show relatively high radioactivity compared to other radioactive waste, such as dry active waste, charcoals, and concrete wastes. The waste acceptance criteria (WAC) of disposal facility defines the structure and property of treated waste. The concentrates and spent resin should be solidified or packaged in high integrity container (HIC) to satisfy the WAC in Korea. The Kori NPP has stored history waste. The large concrete package with solidified concentrates and spent resin. The WAC requires identification of 18 properties for the radioactive waste. Since some of the properties are not clearly identified, the large concrete packages could not satisfy the WAC in this moment. The generation of the large concrete package (rectangular type and cylindrical type), pretreatment of the package, treatment of inner drum, process development for clearance waste, etc. will be discussed in this paper. In addition, the conceptual design of whole treatment process will be discussed.
        7.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        증산은 적정 관수 관리에 중요한 역할을 하므로 수분 스트레스에 취약한 토마토와 같은 작물의 관개 수요에 대한 지식이 필요하다. 관수량을 결정하는 한 가지 방법은 증산량을 측정하는 것인데, 이는 환경이나 생육 수준의 영향을 받는다. 본 연구는 분단위 데이터를 통해 수학적 모델과 딥러닝 모델을 활용하여 토마토의 증발량을 추정하 고 적합한 모델을 찾는 것을 목표로 한다. 라이시미터 데이터는 1분 간격으로 배지무게 변화를 측정함으로써 증산 량을 직접 측정했다. 피어슨 상관관계는 관찰된 환경 변수가 작물 증산과 유의미한 상관관계가 있음을 보여주었다. 온실온도와 태양복사는 증산량과 양의 상관관계를 보인 반면, 상대습도는 음의 상관관계를 보였다. 다중 선형 회귀 (MLR), 다항 회귀 모델, 인공 신경망(ANN), Long short-term memory(LSTM), Gated Recurrent Unit(GRU) 모델을 구 축하고 정확도를 비교했다. 모든 모델은 테스트 데이터 세트에서 0.770-0.948 범위의 R2 값과 0.495mm/min- 1.038mm/min의 RMSE로 증산을 잠재적으로 추정하였다. 딥러닝 모델은 수학적 모델보다 성능이 뛰어났다. GRU 는 0.948의 R2 및 0.495mm/min의 RMSE로 테스트 데이터에서 최고의 성능을 보여주었다. LSTM과 ANN은 R2 값이 각각 0.946과 0.944, RMSE가 각각 0.504m/min과 0.511로 그 뒤를 이었다. GRU 모델은 단기 예측에서 우수한 성능 을 보였고 LSTM은 장기 예측에서 우수한 성능을 보였지만 대규모 데이터 셋을 사용한 추가 검증이 필요하다. FAO56 Penman-Monteith(PM) 방정식과 비교하여 PM은 MLR 및 다항식 모델 2차 및 3차보다 RMSE가 0.598mm/min으로 낮지만 분단위 증산의 변동성을 포착하는 데 있어 모든 모델 중에서 가장 성능이 낮다. 따라서 본 연구 결과는 온실 내 토마토 증산을 단기적으로 추정하기 위해 GRU 및 LSTM 모델을 권장한다.
        4,300원
        8.
        2023.10 구독 인증기관·개인회원 무료
        We analyzed comparatively the ground beetle communities of 1993 and 2023, with 30 year interval, in broadleaf and coniferous stands of the Gwangneung forest, a biosphere reserve in South Korea. 2,906 individuals (53 species, 38 genera, and 15 families) were collected from broadleaf stands and 1,782 individuals (36 species, 32 genera, and 14 families) from coniferous stands in 1993. The dominant species was Synuchus cycloderus in both stands. In 2023, 1,682 individuals (110 species, 78 genera, 21 families) were collected from broadleaf stands and 990 individuals (92 species, 67 genera, 22 families) from coniferous stands. In 2023, the dominant species were Eucarabus (Parhomopterus) sternbergi sternbergi in broadleaf stands and Coptolabrus jankowskii jankowskii in coniferous stands. Species richness (R'), species evenness (E'), species diversity (H'), and dominance (DI) were all higher than in broadleaf (R'=15.472, E'=0.336, H'=1.601, and DI=0.371) and coniferous (R'=13.756, E'=0.369, H'=1.324, and DI=0.326) forests in 2023.
        9.
        2023.10 구독 인증기관·개인회원 무료
        Until now, in case of Palaearctic region, only one species, Nesendaeus monochrous in this genus was recorded from China. but the biology and life cycle are not clearly known, yet. This species collected from the bud of Glochidion chodoense in Korea for the first time and closely related to Heterochyromera imerodeus Kojima & Morimoto which was recorded only in Japan,. But Nesendaeus monochrous is easily distinguishable from H. imerodeus by the relatively longer elytra with bisinuately round apices. Heterochyromera imerodeus Kojima & Morimoto can be found from Eurya emarginata and Glochidion obovatum in Japan. So, this two species are closely related each other and need more taxonomic study about the generic synonymy or changing the generic position.
        10.
        2023.10 구독 인증기관·개인회원 무료
        Necrophila (Calosilpha) brunnicollis brunnicollis (Kraatz, 1877) is a common necrophagous beetle in the Palaearctic region. The species is often encountered on the corpses of large vertebrates, such as human and pig, and is well recognized as a potentially group of beetles in forensic entomology. All of the developmental stages can be found in the corpse and under the soil near a corpse, which can be used to reconstruct the site, such as estimating PMI(Postmortem interval). However, its larval instar stages were never thoroughly described for identification. In this study, we redescribe the morphological characters of all larval stages of N. brunnicollis for quantitative and qualitative morphological information. In addition, we provide the images of larvae and an indentrifiaction key to larval instars.
        11.
        2023.10 구독 인증기관·개인회원 무료
        The genus Silpha Linnaeus, 1758 in Silphinae includes 33 species worldwide. This group is flightless and known to feed on invertebrate carcasses from the ground surface. In South Korea, 3 species have been recorded, and S. koreana Cho& Kwon, 1999 is an endemic species, distributed only Mt. Taebaek and Mt. Mindung. Up to date the immature stages of the species has never been studied although the species has significant value as an endemic species. The present study is the very first one ever conducted describing the larval morphological characters of S. koreana along with images of larval stages. Furthermore, we report observations on developmental lengths for each stages of the species.
        12.
        2023.10 구독 인증기관·개인회원 무료
        Callipogon relictus, a natural monument, is an insect whose life cycle was assumed to take more than 5 years in nature. Winter is a very harsh season, but it is known to be a crucial condition for many insects’ growth. However, no information is known about the overwintering condition and its effects on C. relictus. To understand the overwintering effects on the growth of C. relictus, we investigated the growth patterns of its larvae in indoor conditions after chilling treatment. The larvae were induced to dormancy at low temperature (4°C) for two months, and put them into 10°C for two weeks to break dormancy. After awakening, the temperature was increased 15°C, 20°C to 25°C at a time, and the larvae were kept for two weeks at each temperature. The larvae were divided into 3 groups (3rd to 5th instar, 6th to 8th instar, 9th to last instar). Lastly, head width and weight of the larvae were measured every 30 days under 25°C condition, and mortality and deformity were counted as well. The mortality and deformity rates were the highest in the first group, and the rates decreased toward the last group. On the other hands, growth rate appeared opposite to mortality and deformity rate of each larval group.
        13.
        2023.05 구독 인증기관·개인회원 무료
        Tritium is a radioactive isotope of hydrogen with a half-life of about 12.3 years, and it is commonly found in the environment as a result of the production of Nuclear Power Plants. The World Health Organization (WHO) has established guidelines for the permissible levels of tritium in drinking water. The guideline value for tritium in drinking water is 10,000 Bq/L. It is important to note that the guideline value for tritium is not a legal limit, but rather a recommendation. National and local authorities may establish legal limits that are more restrictive than the WHO guideline value based on local conditions and risk assessments. The Australia and Finland have set a limit for tritium in drinking water at 76,103 Bq/L and 30,000 Bq/L respectively, which is more than three to seven times higher compare to guideline value of WHO. The United States Environmental Protection Agency (EPA) has set a maximum contaminant level (MCL) for tritium in drinking water at 20,000 picocuries per liter (pCi/L), which is equivalent to 740 Bq/L. The Health Canada has set a guideline value for tritium in drinking water at 7,000 Bq/L. Assuming drinking water corresponding to each tritium limit (or guideline value) for one year, the expected exposure dose is 0.01 mSv to 1 mSv. It means that the tritium in drinking water below the limits or guideline value does not pose a significant risk to human health.
        14.
        2023.05 구독 인증기관·개인회원 무료
        During the operation of the nuclear power plant, various radioactive waste are generated. The spent resin, boron concentrates, and DAW are classified as a generic radioactive waste. They are treated and stored at radioactive waste building. In the reactor vessel, different types of radioactive waste are generated. Since the materials used in reactor core region exposed to high concentration of neutrons, they exhibit higher level of surface dose rate and specific activity. And they are usually stored in spent fuel pool with spent fuel. Various non-fuel radioactive wastes are stored in spent fuel pool, which are skeleton, control rod assembly, burnable neutron absorber, neutron source, in core detector, etc. The skeleton is composed of stainless 304 and Inconel-718. There are two types of control rod assembly, that are WH type and OPR type. The WH type control rod is composed of Ag-In-Cd composites. The OPR type control rod is composed of B4C and Inconel-625. In this paper, the characteristics and storage status of the non-fuel radioactive waste will be reported. Also, the management strategy for the various non-fuel radioactive waste will be discussed.
        15.
        2023.05 구독 인증기관·개인회원 무료
        The segmentation of activated components is considered as a one of the most important processes in decommissioning. The activated components, such as reactor vessel and reactor vessel internals, are exposed to neutron from the nuclear fuel and classified to intermediate, low, and very low-level wastes. As it is expected, the components, which are closed to nuclear fuel, exhibit higher degree of specific activity. After the materials were exposed to neutrons, their original elements transform to other nuclides. The primary nuclides in activated stainless steel are 55Fe, 63,59Ni, 60Co, 54Mn, etc. The previous study indicates that the specific activity of individual nuclide is strongly depends on the material compositions and impurities of the original materials. The 59Co is the one of the most important impurities in stainless steel and carbon steel. In this paper, the relationship between individual nuclides in activation analysis of activated components was studied. The systematic study on specific activity of primary nuclides will be discussed in this paper to understand the activation tendency of the components.
        16.
        2023.05 구독 인증기관·개인회원 무료
        Dry active waste (DAW) contains substantial amount of cellulose related materials. The DAW are usually classified as low and/or very low-level waste. In Korea, three types of disposal facilities have been considered: silo, engineering barrier, and land-fill. Currently, only the silo type disposal facility is in operation. Around 27 thousand drums were disposed in silo. Massive amount of cement concrete is used in construction of silo. The ground waste, which flow through the concrete structure, shows higher pH than as it is. It is generally known that the pH of silo is ~12.47 in Korea, when considering construction material, filling material, and property of ground water. It is expected that the cellulose in DAW will be partially transformed to isosaccharinic acid (ISA). It is generally accepted that the ISA plays a negative role in safety analysis of disposal facility by stimulation of specific nuclides. Various factors affect the degradation of cellulose containing radioactive waste, such as degree of polymerization, pH of disposal condition, interaction between concrete structure and ground water, etc. In this paper, the disposal safety analysis of cellulose containing radioactive, usually paper, cotton, wood, etc., are studied. The degradation of cellulose with respect to degree of polymerization, pH of neighboring water, filling material of silo, etc. are reviewed. Based on the review results, it is reasonable to conclude that the substantial amount of DAW could be disposed in silo.
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