Currently, the Korea Atomic Energy Research Institute is conducting research on the development of technology to reduce the disposal area for SF (Spent nuclear Fuel). If the main radionuclides contained in SF can be separated and recovered according to their characteristics (long half-life, high mobility and high heat load) and uranium oxide which is expected to be the final residue, can be made into solids, the burden of the permanent disposal area of the SF will be greatly reduced. The waste form that end up in the repository must be verified for ease of manufacture and stability of the block. And, in order to increase the loading efficiency, a large block manufacturing technology is needed. This study describes the background of introducing PSA (Particle Size Analyzer) which is one of the necessary equipment for manufacturing UO2 blocks using slip casting, the method of using the equipment and performance verification of the equipment using standard samples. The particle size affects the sintering quality by the way the particles rearrange themselves during sintering. Powders of small particles are generally less free flowing and more difficult to compress, they form thin pores between the particles and sinter to higher density. In contrast, larger particle has a lower sintered density. Therefore, accurate particle size measurement and the selection of a suitable particle size are important. For this purpose, a PSA was installed in nuclear cycle experiment research center. To verify the performance of the equipment, a standard sample of 1.025 μm was analyzed. We got an average particle size of 1.0293 μm and standard deviation of 0.0668 μm. This value was within the uncertainty(±0.018 μm) of the sample’s certificate. In the future, this equipment will measure the size of UO2 (depleted uranium) powder and to produce large scale uranium oxide blocks.

Expanding exports of small and medium-sized companies is crucial for the continuous growth of the Korean economy. Therefore, the government operates various support systems to enhance the export capabilities of these companies. This study aims to analyze the impact of the Korean government's flagship export support system, known as the export initiation support system, on the performance of participating domestic companies. A fixed effect model using panel data was applied to examine the characteristics of 11,099 companies that participated in the export initiation support system from 2016 to 2019. The analysis revealed that the number of exporting countries, employees, and previous export volume had a significant impact on the export amount of participating companies. However, contrary to expectations, the number of overseas marketing participation and the GCL (global competence level) test did not show a significant impact. This study is significant as it provides implications for the development of support projects tailored to the specific needs of small and medium-sized companies, with the goal of improving the export support system.

An aeroponic seed potato production technology project has been established in Pakistan through the Technical Cooperation Project (TCP) between RDA-KOPIA and PARC. For sustainable potato production, producing high-quality and disease-free potato seeds is critical in Pakistan. The majority of the farmers recycle their own seeds or obtain them through informal ways. Consequently, tuber-borne illnesses proliferate, seeds deteriorate, and yield diminishes. To mitigate such problems, the country moved to sustainable seed potato production by adopting rapid seed multiplication strategies like the combination of tissue culturing with aeroponic seed production technology which is being evaluated as an alternative to traditional pre-basic seed production methods. A series of experiments were carried out to evaluate the shoot development and mini tuber production attributes between two cultivars, different plantlet size and planting period between October 27, 2021, and January 27, 2022, at the NARC aeroponic facility. A CRD design with three replications was used. The study aimed to compare the productivity by variety, plantlet size and planting period to improve aeroponic seed production technology in Pakistan. The results indicated that Lady Rosetta outperformed Asterix in terms of shoot growth and small tuber output. Early planting at an optimal temperature of 27 degrees Celsius in the daytime showed a substantial difference when compared to late planting in November and tuberization was commenced 50-55 days after transplantation. Furthermore, in an aeroponic seed potato production system, normal plantlets (8-10 cm) at the time of transplantation, performed better than medium and small plantlets. In a nutshell, it was determined that normal size plantlets (8-10 cm) of Lady Rosetta cultivar, planted at optimum time to plant showed best results in the aeroponic system at NARC, Islamabad, Pakistan.

The rate of industrial accident reduction is slowing down as the attention of the Ministry of Employment and Labor and related agencies on risk assessment systems decreased. this paper focuses on weakness of legal system for the risk assessment in recent years. A survey was conducted to identify the status and condition of the risk assessment system applying on small and medium-sized manufacturing companies. A set of questionnaires is designed to reflect various perspectives of the companies regarding the problems and solutions of the system. The results refer that differentiated instructions and support systems in response to the actual conditions of the companies are mandatory to reinforce the efficiency of risk assessment system.

중앙해양안전심판원(2019)에서 발표한 최근 5년의 해양사고통계자료에 따르면 충돌사고의 대부분은 20톤 미만의 어선에서 발 생하고 있으며 전방 부주의, 경계 소홀 등의 운항과실로 인한 사고가 주요 원인으로 나타나고 있다. 이러한 사고 방지를 위해 운항자를 대상으로 훈련 및 교육을 강화하고 있지만 충돌사고는 빈번히 발생되고 있으며 충돌 사고를 줄이기 위한 기술적인 방안 또한 지속적으로 개발중에 있다. 본 연구에서는 고속 활주형 소형 선박에 WAVE 통신 기술을 적용하여 선박 간 거리, 속도, 방위에 기반한 조우 상황을 고 려하여 충돌 회피 동작이 가능한 제어 알고리즘을 개발하였으며, WAVE 통신-제어기를 결합하여 충돌 회피 시스템을 구축하였다. 그리고 충돌 회피 동작의 검증을 위해 두 소형 선박간의 정면, 추월, 교차의 3가지의 조우 시나리오에 대해서 시뮬레이션을 수행하고 실선 시험 을 통해서 충돌 회피 알고리즘을 검증하였다.

In general, small and medium-sized computer rooms do not have access floors for reasons of increased floor height and increased construction cost. Therefore, the air conditioning method used here applies the method of directly blowing the cold air of the air conditioner into the computer room. In this case, the hot/cold air is not separated, and as the hot air is recirculated, it is re-introduced to the front of the server rack, resulting in a problem that the server cooling efficiency is decreased. In addition, in such a computer room structure, it is difficult to configure and install a containment system. In this study, we tried to understand the problem of the formation airflow in the case of using the existing air conditioning method, and to find a method of configuring the air conditioning environment to improve the cooling efficiency. The purpose of this study was to understand the airflow/temperature distribution in the computer room using the CFD simulation method. In addition, the thermal characteristics of various air-conditioning environments such as the location of the CRAC cold air discharge location, the layout between server rack and CRAC and the containment were reviewed.

In in vitro fermentation studies, feed samples can either be included in the in vitro rumen medium using filter bags or can be directly dispersed. The objective of this study was to investigate the effects of different pore sizes of filter bags on the rumen fermentation characteristics in an in vitro system. Corn, soybean meal, and timothy were ground to pass through a 1.0-mm screen and were formulated in the ratio of 70:7:23 based on DM, respectively. The formulated experimental diet (2g/DM) was put in F57 filter bags and R510 nylon bags (Ankom®) which pore sizes were 25 and 50 μm, respectively. An in vitro study was conducted to determine the rumen fermentation characteristics for 3, 6, 12, 24, and 48 h and rumen microbial community at 48 h of incubation. A significantly higher production of gas was observed in the R510 bags than in F57 at all the incubation times (p<0.01). IVDMD (p<0.01) and IVNDFD (p<0.01) were significantly higher, whereas pH (p<0.01) and NH3-N (p<0.01) were lower when R510 bags were used. In the VFA composition, acetate and butyrate were significantly higher (p<0.01) in R510 bags, and propionate and total VFA concentration did not differ (p=0.55 and 0.25, respectively) between F57 and R510 bags. The log copy numbers of bacteria and protozoa did not differ (p=0.69 and 0.94, respectively) between F57 and R510 bags, whereas those of fungi were significantly higher in R510 than in F57 bags (p<0.01). Therefore, the use of R510 may reflect actual rumen fermentation characteristics more precisely than those of F57 because increased gas production, nutrient digestibility and acetate, butyrate proportion were founded in R510.

Seafood is attracting attention as a future food industry. In recent years, the demand for fishery equipment of mechanization, automation, and unmanned was increased due to the environment affected by seafood processing, stricter regulations on safety, decline and aging of fishery worker. Ark shell (Scapharca subcrenata) was being produced in many steps in the production process. The process has been made such as collection–landing–washing–first sort (goods/non-goods)–transports– second sort (size). It was undergone first and second steps by delivering to the consumer. Here, the first step is to sort goods to collection and the second step is to sort by size. The fishery workers need ten people in first step and six people in second step. The workload of one hour per kg is 4,247 kg/h in first step and 2,213 kg/h in second step. In addition, the goods ratio by work process was 79% in first step and 98% in the second step. In this process, a lot of fishery worker and working time is needed. Therefore, this study developed elemental techniques for an automated size sorting system considering the working process problem, time and situation for washing and sorting of ark shell.

하수오(Polygonum multiflorum Thunb.)는 여뀌과에 속하는 초본식물로 동아시아와 북아메리카에 자생하고 있다. 하수오는 관상용으로도 이용되며, 한의학에서 뿌리를 약용으로 사용한다. 하지만 월동 이 어렵고 노동력 소모가 많아 최근 재배농가가 감소하고 있다. 본 연구에서는 하수오의 우량종묘를 짧 은 시간에 대량생산하기 위하여 수경재배에 적합한 양액과 조직배양묘의 크기를 조사하였다. 토양에 적 응이 완료된 하수오 종묘는 크기에 따라 Type 1, Type 2 및 Type 3으로 나누어 4종류의 양액에 치상 하였다. 치상 후 양액과 종묘에 따른 생육차이를 확인하기 위하여 생육조사를 실시하였다. 생육조사는 8주 동안 양액에서 생육시킨 후 줄기길이, 잎 수, 마른 잎 수, 줄기 수, 생체중과 건물중에 대해 측정 하였다. 그 결과 양액3에서 Type 1과 Type 2의 뿌리길이는 각각 33.8cm와 29.5cm로 각각 나타났다. 이와 유사한 경향으로 덩굴 길이도 CaCl2가 첨가 된 양액3에서 Type 1과 Type 2가 가장 길게 나타나 우수한 생육을 보였다. 이처럼 뿌리가 증대된 종묘는 밭으로 이식 될 때 활착을 도와 우수한 초기생육 을 나타낼 것이라 사료된다. 반면 Type 3는 잎끝마름과 고사하는 현상을 보여 추후 양액의 적정농도에 대한 추가 실험이 필요할 것이라 사료된다.

PURPOSES : This study primarily focused on evaluating the performance characteristics of 4.75-mm nominal maximum aggregate size (NMAS) asphalt mixtures for their more effective implementation to a layered flexible pavement system. METHODS: The full-scale pavements in the FDOT’s accelerated pavement testing (APT) program, including 4.75-mm mixtures at the top with different thicknesses and asphalt binder types, were considered for the faster and more realistic evaluation of the rutting performance. The results of superpave indirect tensile (IDT) tests and hot-mix asphalt fracture mechanics (HMA-FM) based model predictions were used for cracking performance assessments. RESULTS: The results indicated that the rutting performance of pavement structures with 4.75-mm mixtures may not be as good as to those with the typical 12.5-mm mixtures, and pavement rutting was primarily confined to the top layer of 4.75-mm mixtures. This was likely due to the relatively higher mixture instability and lower shear resistance compared to 12.5-mm mixtures. The energy ratio (ER) and HMA-FM based model performance prediction results showed a potential benefit of 4.75-mm mixtures in enhanced cracking resistance. CONCLUSIONS : In relation to their implementation, the best use of 4.75-mm mixtures seem to be as a surface course for low-trafficvolume applications. These mixtures can also be properly used as a preservation treatment that does not necessarily last as long as 12.5-mm NMAS structural mixes. It is recommended that adequate thicknesses and binder types be considered for the proper application of a 4.75-mm mixture in asphalt pavements to effectively resist both rutting and cracking.

This study investigates the size marking differences in domestic and international cycle wear brands offered in Korea and provides basic material to develop a size system for cycle wear suitable for the Korean somatotype. Study methods include size systems suggested in the web-sites of domestic and international cycle wear brands offered in Korea. Brands used for the study included 8 brands (3 domestic brands, 2 Italian brands, 1 Australian brand, 1 Swiss brand and 1 Japanese brand). The results of this study were as follows. Domestic brand A company marked the size from 85 to 110 based on height(cm) and weight(kg) and indicated the actual size of the product for customers to refer to. Domestic brand B company marked the size from ES:85 to 2XL:110 based on height(cm) and weight(kg), Domestic brand C company marked unisex size from XS to XXL based on weight(kg) and height(cm) and waist circumference(inch)with a separately marked women size XS-M. Italian brand, D company marked size from S-4XL for men based on height, chest, waist, hip circumference size(cm) and XS-2XL for women. Italian brand F company marked size from S-3XL for men and XS-XL for women based on chest, waist and hip circumference size(cm). Japanese brand G company marked size fromS-3L for men based on height, chest, waist circumference size(cm) and S-XL for women based on height, chest, waist and hip circumference size(cm). Australian brand H company marked sizes as XS-XXL based on chest circumference size(cm) for upper clothes for men and for women XXS-XL. For bottom clothes, they marked sizes XS-XXL for men based on waist circumference size(inch) and XXS-XL for women based on waist and hip circumference size(inch). Swiss brand, I company marked men sizes as XS-XLG and TIR based on a chest circumference size(cm) based on height(cm) for bottom clothes and chest circumference size(cm) for upper clothes with XS-XL for women based on a hip circumference size(cm) for bottom clothes and chest circumference size(cm) for upper clothes. In conclusion, domestic brands have a wide range of sizes and utilize a range of weight against height to cover various body somatotype. The Italian brand indicated that S size is bigger than other brands when it comes to deviation and a relatively small size tolerance with each size. Japanese brands have a well-organized size system based on height and basic body measurements. Australian brand are variously distributed without regular dimension tolerances for each size and Swiss brands have bigger round sizes. The investigation of size marking for domestic and international cycle wear showed that cm and inch are combined and that each country has a different size system with significant difference in dimension and size deviation. Thus, there is a need to establish standards and develop a domestic size system for international cycle wear and the purchase of overseas brands. However, it has the limitation in generalization of results because there is a little investigation brand.

This study is aimed comparative analysis for business performance of land-based ezo abalone (Haliotis discus hannai) seed farms by standardizing cost structures by region and farming size. The result of survey on average farming incomes by region showed that farming incomes in Haenam and Jindo regions were much higher than those in other regions. Followed by Wando region, incomes in other regions were analyzed to be relatively lower. It is shown that farming incomes became higher as farm size increased. Farming incomes per unit size which were modified from farming incomes by region were highest in Jindo region, followed by East sea region, Wando and Haenam regions. Incomes in Jeju and Yeosu regions were analyzed to be relatively lower. Results on farming incomes per unit size (m2) showed that both farming incomes and profits became higher as size increased. It implies that a scale effectiveness might exist in case of land-based abalone culture system. Impacts of major factors on farming profits and returns on investment in abalone seed aquaculture are summarized as follow. First, only if the survival rate increased by 10% with improvement of component ratio, variable effects became largest. In variable effects of other factors, a variation in Jindo region was largest and on the other hand, a variation in Yeosu region was shown to be smallest.

The purpose of this study is to validate and verify a head nose exposure inhalation system for nano particle inhalation toxicity studies. Carbon nano tube(CNT) particles were generated by a chemical vapor deposition(CVD) generator. And purchased single wall carbon nanotubes(SWCNT) and multi wall carbon nanotubes(MWCNT) were generated by an atomizer. CNT particle distribution was measured by Scanning Nano-Particle Spectrometer(SNPS) and Condensation Particle Counter(CPC). Diameter and length of MWCNT generated by CVD were 10~40 nm and 220~20 μm respectively. Particle number concentration of MWCNT generated by CVD were 1.3×105, 4.1×104, 5.6×103#/cc in high, middle, low chamber respectively. Distribution of particles which were less than 100 nm was 45%. Particle number concentration of SWCNT generated by atomizer after magnetic stirring were 8.5×106, 5.3×105, 1.1×104#/cc and after sonication 6.7×106, 4.1×105, 9.5×103#/cc in high, middle, low chambers respectively. Particle number concentration of SWCNT generated by atomizer after magnetic stirring were 6.7×106, 4.6×105, 8.6×103#/cc and after sonication 7.7×106, 5.1×105, 1.3×104#/cc in high, middle, low chambers respectively. We set up head nose exposure inhalation system to conduct a study on nano particle inhalation toxicity. There were sufficient particle number concentrations of nano particles generated in each chamber.

본 연구는 폐쇄형 육묘 시스템에서의 파프리카 묘 생산에 적합한 재배 기간 및 암면 블록의 크기를 구명하기 위하여 수행되었다. 파프리카 종자를 세 가지 크기의 암면 블록(45 × 40 × 35, 70 × 70 × 60, 100 × 100 × 65mm)에 파종하고 형광등을 인공 광원으로 이용하는 폐쇄형 육묘 시스템에서 23, 30, 37일간 재배하였다. 또한, 온실에서 100 × 100 × 65mm의 암면 블록을 이용하여 관행 재배한 파프리카 묘를 온실 처리구로 설정하였다. 육묘 일수와 관계없이 70 × 70 × 60mm의 암면 블록에서 육묘한 파프리카 묘의 지상부, 지하부 생육 및 R/S율이 가장 높았으며, 온실에서 관행 재배한 처리구보다 폐쇄형 육묘 시스템에서 재배한 파프리카 묘의 소질이 우수하였다. 폐쇄형 육묘 시스템과 온실에서 23, 30, 37일간 재배한 파프리카 묘를 암면 슬라브에 정식하고 초기 수량을 조사하였다. 파종 후 125일의 파프리카 평균 과중은 암면 블록 크기와 육묘 일수의 영향을 거의 받지 않았으나, 단위 면적당 수량은 70 × 70 × 60와 100 × 100 × 65mm의 암면 블록을 이용하여 23일간 폐쇄형 육묘 시스템에서 재배한 처리구에서 가장 높았다. 따라서, 폐쇄형 육묘 시스템에서 파프리카 육묘 시 관행 재배보다 작은 70 × 70 × 60mm의 암면 블록을 이용하고 육묘 일수를 23일로 단축하여도 우수한 품질의 파프리카 묘를 생산할 수 있음을 확인하였다.

ZnO nanoparticles in the size range from 5 to 15 nm were prepared by zinc-lithium-acetate system. The morphologies and structures of ZnO were characterized by TEM, XRD and FT-IR spectra. UV-visible results shows that the absorption of ZnO nanoparticles is blue shifted with decrease in particles size. Furthermore, photoluminescence spectra of the ZnO nanoparticles were also investigated. The ZnO nanoparticles have strong visible-emission intensity and their intensities depend upon size of ZnO nanoparticles.

This paper deals with the picking batch size which a bi-directional carousel system can be feasible. The items that customers order are retrieved from the bins of carousel with batch size. The mathematical equations representing rotary travel distance and retrieval lead time to pick a given batch size are derived. Rotary travel distance represents the distance which carousel system rotates to retrieve items in a batch. The bi-directional carousel system rotates to minimize the travel distance in retrieving the items in a batch. Rotary travel distance and retrieval lead time are analyzed for the batch size through the simulation approach. From the simulation, the retrieval batch size that carousel system can be feasible is obtained. A numerical example is shown to explain the solution procedure.

This paper is to analyze the picking lead time for picking batch size in a warehouse system and to get minimum picking batch size that is the warehouse system feasible. The warehouse system consists of aisles and racks, which two racks face each other through aisle. The products are picked from the storage locations by batch size. The probability that items are picked in the each row of the rack in the aisle for order picking activity is derived. The picking lead time for picking batch size is the time passed from the first picking location to arrival at starting location in aisle picking all items included in a batch size. The picking lead time for picking batch size in an aisle is analyzed. The picking lead time for picking batch size in the whole warehouse system is obtained. The warehouse system is feasible if all items that customers order are picked from the storage locations for same period. The picking batch size that is the warehouse system feasible is obtained. The problem is analyzed, a solution procedure is developed, and a numerical example is shown to explain the problem.