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        검색결과 387

        21.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        22.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Currently, the budget for vocational competency development training has been expanded, but the number of participants has decreased. As the budget for the Vocational Competency Development Project increases, the participation of a large number of people becomes necessary. This study aims to derive factors that affect satisfaction by selecting factors related to respondent characteristics, training institutions, training types, and job performance for satisfaction with vocational competency development training, and to study ways to improve satisfaction. Data were collected through focus group interviews (FGI), and logistic regression analysis was conducted through feasibility review and reliability analysis. As a result, in the case of the model, it was confirmed that the degree of agreement between the case actually measured and the case predicted by the model was low in the Hosmer and Lemeshow test, but the overall classification accuracy was classified as 96.0% in the classification accuracy table. As for the influence of the factors, the result was derived that the application of knowledge technology, training institution facility equipment, Business Collaboration, long-term work plan, and satisfaction with work performed have an influence in the order.
        4,000원
        23.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Severe Disaster Punishment Act had recently been established in order to promote safety and health (OSH) management system for severe accident prevention. OSH management system is primarily designed based on risk assessments; however, companies in industries have been experiencing difficulties in hazard identification and selecting proper measures for risk assessments and accident prevention. This study intended to introduce an accident analysis method based on epidemiological model in finding hazard and preventive measures. The accident analysis method employed in this study was proposed by the U.S. Department of Energy. To demonstrate the effectiveness of the accident analysis method, this study applied it to two accident cases occurred in construction and manufacturing industries. The application process and results of this study can be utilized in improving OSH management system and preventing severe accidents.
        4,000원
        25.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국제사회는 글로벌 기후위기 극복을 위해 2050년까지 탄소중립(Net Zero)을 목표로 다양한 탈탄소 에너지원 개발을 지속하고 있다. 우리 정부에서도 ‘재생에너지 3020’ 정책을 수립하고 태양광이나 풍력을 이용한 에너지 개발계획을 추진함에 따라 해상 풍력발전단 지와 같이 연안해역에서 기존에는 볼 수 없었던 대규모 해양개발사업이 추진되고 있다. 해양시설물은 선박의 입장에서 볼 때는 항행 장 애물의 일종이며, 해양시설물 설치에 따라 좁아진 수역에서 선박 간 충돌사고 발생 또는 선박과 해양시설물의 접촉사고 발생시 환경오염 및 인명피해 등의 발생이 우려된다. 이에 국내외의 해상풍력발전단지 개발계획을 살펴보고 풍력단지에서 선박의 안전한 통항을 보장하기 위한 제도적 장치가 완비되어 있는지 분석하였으며, 해외의 입법 사례와 국내 법규를 비교하여 법적 사각지대를 해소하기 위한 새로운 법령안을 제안함으로써 대한민국의 관할해역에서 해양시설물의 안전한 운영과 선박의 안전한 통항을 기대하였다.
        4,300원
        26.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        해양을 이용하려는 수요자 증가에 따라, 해양공간을 합리적으로 배분하기 위해 해양공간계획(Marine Spatial Planning)제도가 도 입되었다. 이 중 어업활동보호구역은 수산자원보호 등 어업활동 보호를 위해 지정되었다. 그러나, 어업활동보호구역을 주로 항해하는 어 선은 우리나라에서 발생하는 해양사고의 약 70 %를 차지할 정도로 위험에 노출되어 관리가 필요하다. 본 연구의 목적은 어업활동보호구 역 내 어선 통항 안전 확보를 위해 어업활동보호구역과 항만·항행구역에서 발생하는 해양사고를 분석하는 것이다. 이를 위해 해양용도구 역의 교통량을 조사하고 선종별, 사고 유형별, 톤수별, 사고원인별, 인명피해별로 해양사고를 조사하였다. 분석 결과 각 유형별 단위 면적 당 해양사고는 대부분 항만·항행구역에서 더 많이 발생하였으나 전체적으로 발생한 해양사고는 어업활동보호구역이 높았다. 특히 인명사 고가 많이 발생하여 통항 안전관리가 필요한 것으로 식별되었다.
        4,000원
        29.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to explore the appropriate water pressure control of water supply pipeline to reduce water losses of water supply network in Jinan-gun. The current water pressure status of each 5 blocks and the impact of optimized water pressure on improving revenue water rate were investigated. In order to obtain the flow rate and water pressure data of each small block, a smart hub is set in the pressure reducing valve chamber at the inlet of the small block, and a smart water pressure meter is installed in the fire hydrant and the faucet of the customer. For the pressure reducing valves installed for water pressure management system of each block, the diameter calculation standard and type of the pressure reducing valve are determined, and the application reasons are put forward. The analysis results of water pressure management for each small block in Jinan-gun show that the pressure control equipment and water pressure management need to be improved in four small blocks. The water flow rate in Jinan-eup and Sangjeon-myeon increases from 57.2% to 87.6% when the water pressure control is completed.
        4,000원
        31.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The flange spreader has been used to withdraw butterfly valves during maintenance. The typical flange spreaders required an excessive working space, and the pipe and flange are damaged by the load. In the previous study, the author developed a valve easy out tool with collet, and designed collet shape to ensure structural safety. However, clamping force of the collet had not been checked. In this study, design of collet shape was performed to improve clamping force. Techniques of structural analysis were established and design parameters were selected. Through parametric study, the collet shape with clamping force of 159,748N was suggested. This will contribute to stability and efficiently of valve maintenance.
        4,000원
        32.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Forest fires in Korea usually start in the fall and occur every year until spring. Most wildfires are human resources that combine topographical characteristics and carelessness, and failure to respond in the initial stage and lack of cleanup are spreading to large-scale wildfires. In order to prevent these wildfires, active cooperation from the public is essential. As can be seen from recent wildfires, the attention of the public is needed above all else because large-scale wildfires in Korea are occurring due to the people's negligence. If a wildfire spreads and becomes large, it causes damage to life and property, and the damage is irreversible. In this study, various methods were used to prevent forest fires and improve initial suppression ability. In order to minimize damage, the model analyzed by the 119 Special Rescue Team in Gangwon, Chungcheong and nearby forest fires was analyzed on the combustion progress and wind direction by time period. The propagation speed by the wind direction was simulated. Until now, most of the wildfires have been extinguished by firefighting, but I hope that the Forest Service will take the lead and maintain coordination with related organizations.
        4,000원
        33.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The effects of strontium cations on the strength of hydrated cement composites as well as the morphology and chemical composition changes of cement hydrates due to strontium treatment are investigated in this study. Subsequently, the potential of a strontiumbased aqueous solution as a near-surface treatment method for hydrated cement composites is evaluated. METHODS : To supply strontium cations to a hydrated cement composite, a 30% strontium nitrate aqueous solution was used. Cement paste (w/c = 0.4) specimens were prepared and cured in the 30% strontium nitrate aqueous solution, which allows the strontium ions to penetrate into the specimen and treat the near-surface region. Compressive and flexural strength tests were performed on both specimens treated by the strontium ions and untreated specimens cured in deionized water, and the test results were compared. To investigate the changes in the morphology and chemical compositions of the cement hydrates due to the treatment, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analyses were performed. RESULTS : The results of the strength tests indicate that both the compressive and flexural strengths of the specimens cured in the 30% strontium nitrate aqueous solution improved significantly compared with the specimens cured in deionized water for the same duration. In particular, the strontium nitrate aqueous solution shows greater improvement in terms of the flexural strength compared with the compressive strength. The maximum penetration depth of strontium into the hydrated cement composite is 5 mm during the first 7 d of immersion and increases to 6.5 mm during the subsequent 14 d. The SEM results show that the microstructure of the hydrated cement composite is densified by the strontium nitrate aqueous solution treatment. The EDS results show that morphology and chemical compositions of the cement hydrates are altered. This implies that the strontium cations can be combined with C–S–H and C–S–A–H phases to form new types of hydrates. CONCLUSIONS : The experimentally results show that the strength of hydrated cement composites can be improved by modifying their near-surface regions via the strontium cation penetration technique. This implies that the strontium-based aqueous solution exhibits high potential for the maintenance and rehabilitation of concrete structures.
        4,000원
        34.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In SRC column, the closed hoops are applied with the same detail of both 135° standard hooks to expect the same performance as hoops of RC columns. This standard detail is actually complicated to construct, thus, two separating rebars are connected in the form of a square shape and welded over the overlapping section. But this is also complicated in construction practice. Therefore, this study describes experimental results regarding cyclic behaviors shown with alternative hoops cramped by the steel clip type-binding device instead of welding and standard specimen. As a result of the experiment, the specimens with alternative hoops of the SRC column showed comparable performance to the specimens with closed hoops. Therefore, it can be evaluated that the alternative hoops applied with the rebar confinement clips in the SRC column can replace the closed hoop.
        4,300원
        35.
        2022.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Neuromuscular electrical stimulation (NMES) is used for muscle strengthening. While voluntary muscle contraction follows Henneman et al.’s size principle, the NMES-induced muscle training disrespects the neurophysiology, which may lead to unwanted changes (i.e., declined balance ability). Objects: We examined how the balance was affected by abdominal muscle training with the NMES. Methods: Fifteen young adults (10 males and 5 females) aged between 21 and 30 received abdominal muscle strengthening with NMES for 23 minutes. Before and after the training, participants’ balance was measured through one leg standing on a force plate with eyes open or closed. Outcome variables included mean distance (MDIST), root mean square distance (RDIST), total excursion (TOTEX), mean velocity (MVELO), and 95% confidence circle area (AREA) of center of pressure data. Two-way repeated measures analysis of variance was used to test if these outcome variables were associated with time (pre and post) and vision. Results: All outcome variables were not associated with time (p > 0.05). However, all outcome variables were associated with vision (p = 0.0001), and MVELO and TOTEX were 52.4% (45.5 mm/s versus 95.6 mm/s) and 52.4% (364.1 mm versus 764.5 mm) smaller, respectively, in eyes open than eyes closed (F = 55.8, p = 0.0005; F = 55.8, p = 0.0005). Furthermore, there was no interaction between time and vision (F = 0.024, p = 0.877). Conclusion: Despite the different neurophysiology of muscle contraction, abdominal muscle strengthening with NMES did not affect balance.
        4,000원
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