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        검색결과 8,361

        41.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study deals with the application of an artificial neural network (ANN) model to predict power consumption for utilizing seawater source heat pumps of recirculating aquaculture system. An integrated dynamic simulation model was constructed using the TRNSYS program to obtain input and output data for the ANN model to predict the power consumption of the recirculating aquaculture system with a heat pump system. Data obtained from the TRNSYS program were analyzed using linear regression, and converted into optimal data necessary for the ANN model through normalization. To optimize the ANN-based power consumption prediction model, the hyper parameters of ANN were determined using the Bayesian optimization. ANN simulation results showed that ANN models with optimized hyper parameters exhibited acceptably high predictive accuracy conforming to ASHRAE standards.
        4,500원
        42.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study aimed to secure the work space in alarm valve rooms to ensure stable working conditions for the engineers. METHODS : We analyzed situations where alarm valve room work spaces were inadequately secured posing a problem. Using the Ovako working posture analysis system (OWAS) method, we measured the body size of adult male technicians and their tools to analyze the actual space needed for them to maintain a healthy posture while working. On this basis, we proposed regulations governing workspace size and acceptable durations for unstable body postures. RESULTS : By measuring valve room work space and technician body size, we found that the workspace was inadequate for technicians. Applying OWAS showed that securing more space in the valve room improved the construction stability. CONCLUSIONS : Regulations on valve room size and appropriate work space for technicians will improve construction and inspection stability. This reduces the probability of poor construction and inadequate inspection, increasing the reliability of the firefighting facility system.
        4,000원
        43.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, theoretical analyses are performed to investigate the characteristics of the static and dynamic stiffness of a nonlinear vibration isolator system. The vibration isolator system is modeled as an equivalent nonlinear oscillator. Based on the model, the static equilibrium and frequency response solutions are obtained with the variations of external static load and/or system parameters. It is shown that the static stiffness of the nonlinear vibration isolator tends to be hardened with the increase of external static load, which prevents the occurrence of excessively large deflection. This static stiffness-hardening effect is more remarkable with a larger spring constant ratio. The dynamic stiffness is also strengthened when the spring constant ratio increases, which enlarges the force transmissibility and reduces the isolation frequency bandwidth. Thus, the static stiffness- hardening improves the robustness of the nonlinear vibration isolator, whereas the dynamic stiffness-hardening rather degrades its performance. Thus, the opposite tendency of the static and dynamic stiffness-hardening effects should be considered in the design process of the nonlinear vibration isolator.
        4,000원
        44.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Painting pretreatment is an important task in determining the life of painting as it removes rust or foreign substances from the painting surface and gives adhesion between the painting surface and the painting surface. Since painting pretreatment is an important task, IMO strictly requires that the painting pretreatment surface be maintained at a Sa 2.5 grade and the surface roughness is 30μm~75μm. Painting pre-processing is an important task that determines the lifespan of a painting, but it is done through visual inspection by the inspector, and the quality varies depending on the inspector. In this study, in order to develop a quality measurement system for the painting pretreatment surface, Matlab2023b was used to determine the range of appropriate quality brightness by comparing the brightness of the painting pretreatment surface and surface roughness.
        4,000원
        45.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Wastewater management is increasingly emphasizing economic and environmental sustainability. Traditional methods in sewage treatment plants have significant implications for the environment and the economy due to power and chemical consumption, and sludge generation. To address these challenges, a study was conducted to develop the Intermittent Cycle Extended Aeration System (ICEAS). This approach was implemented as the primary technique in a full-scale wastewater treatment facility, utilizing key operational factors within the standard Sequencing Batch Reactor (SBR) process. The optimal operational approach, identified in this study, was put into practice at the research facility from January 2020 to December 2022. By implementing management strategies within the biological reactor, it was shown that maintaining and reducing chemical quantities, sludge generation, power consumption, and related costs could yield economic benefits. Moreover, adapting operations to influent characteristics and seasonal conditions allowed for efficient blower operation, reducing unnecessary electricity consumption and ensuring proper dissolved oxygen levels. Despite annual increases in influent flow rate and concentration, this study demonstrated the ability to maintain and reduce sludge production, electricity consumption, and chemical usage. Additionally, systematic responses to emergencies and abnormal situations significantly contributed to economic, technical, and environmental benefits.
        4,000원
        46.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1개월과 3개월 장기 예보를 지원하기 위해 기상청에서 현업운용 중인 GloSea6 기후예측시스템에는 대기 중 대 기화학-에어로졸 물리과정(UKCA)이 연동되어 있지 않다. 본 연구에서는 저해상도의 GloSea6와 여기에 대기화학-에어로 졸 과정을 연동시킨 GloSea6-UKCA를 CentOS 기반 리눅스 클러스터에 설치하여 2000년 봄철에 대한 예비적인 예측 결과를 살펴보았다. 현업 고해상도 GloSea6 모델이 방대한 전산자원을 필요로 한다는 점을 고려할 때, 저해상도 GloSea6와 GloSea6-UKCA 모델은 대기화학-에어로졸 과정의 연동에 따른 효과를 살펴보기에 적합하다. 저해상도 GloSea6와 GloSea6-UKCA는 2000년 3월 1일 00Z부터 75일 간 구동되었으며, 두 모델이 예측한 2000년 4월 지상 기온과 일평균 강수량의 공간 분포를 ERA5 재분석자료와 비교하였다. GloSea6-UKCA가 예측한 기온과 강수 분포는 기존 GloSea6에 비해 ERA5 재분석자료에 보다 더 유사해졌다. 특히 우리나라를 포함한 동아시아 지역에 대해 과대 모의 경 향이 있던 봄철 지상 기온과 일평균 강수량의 예측 결과의 개선이 주목할 만하다. 또한 적분 시간에 따른 예측된 기온 과 강수량의 시계열에서도 GloSea6-UKCA가 GloSea6보다 재분석자료에 더 가까워진 시간 변화 경향을 살펴볼 수 있었 다. 이는 대기화학-에어로졸 과정이 GloSea6에 연동되었을 때 동아시아지역 봄철 예측 성능이 개선될 수 있음을 보여준다.
        5,200원
        47.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 글의 목적은 지난 21대 총선과 한국의 민주주의를 반추(反芻)하면 서 한국의 민주주의에 얼마나 국민적 가치를 보여줄 수 있는가를 고찰하 는 데 있다. 이 연구는 21대 총선에서 준연동형 비례대표제 도입이 여야 거대 양당의 공천과정에 어떤 변화를 보여주는지를 선거제도의 비례성과 당내 공천과정의 민주성을 중심으로 평가하고자 한다. 이 연구의 결과, 준연동형 비례대표제 도입의 변칙성, 준연동형 비례대표제의 비례성의 감소, 거대 양당에 의한 위성정당 난립과 비제도화, 공천과 공직후보자 추천에서 정당의 당내 민주화 부재를 보여주었다. 따라서 총선을 통해 당내 민주주의를 정착시킬 수 있는 것은 당리당략이 아닌 여야 합의에 의한 비례대표제 채택, 제대로 된 국회의원 선거제도에서의 비례성 확대, 거대 양당에 의한 위성정당 난립 방지 위한 정당법 및 선거법의 개정, 비례대표 의석을 거대 양당 배제하고 군소정당만으로 전국 득표율 수 에 따라 배분, 총선과정에서의 정당의 비민주적 행태 지양과 당내 민주 주의 확대하는 것이다.
        8,100원
        48.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The dyeing process is a very important unit operation in the leather and textile industries; it produces significant amounts of waste effluent containing dyes and poses a substantial threat to the environment. Therefore, degradation of the industrial dye-waste liquid is necessary before its release into the environment. The current is focusing on the reduction of pollutant loads in industrial wastewater through remediating azo and thiazine dyes (synthetic solutions of textile dye consortium). The current research work is focused on the degradation of dye consortium through photo-electro-Fenton (PEF) processes via using dimensionally stable anode (Ti) and graphite cathode. The ideal conditions, which included a pH of 3, 0.1 (g/L) of textile dye consortium, 0.03 (g/L) of iron, 0.2 (g/L) of H2O2, and a 0.3 mAcm-2 of current density, were achieved to the removal of dye consortium over 40 min. The highest dye removal rate was discovered to be 96%. The transition of azo linkages into N2 or NH3 was confirmed by Fourier transforms infra-red spectroscopic analysis. PEF process reduced the 92% of chemical oxygen demand (COD) of textile dye consortium solution, and it meets the kinetics study of the pseudo-first-order. The degradation of dye through the PEF process was evaluated by using the cyclic voltammetric method. The toxicity tests showed that with the treated dye solution, seedlings grew well.
        4,800원
        49.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzes the body shapes of lower-body obese female adolescents and proposes a slacks pattern suitable for their body type. Lower-body obesity is a prevalent type of teenage obesity, and our proposals aim to improve consumer satisfaction in ready-to-wear clothes across this demographic. We first observe characteristics of obese lower bodies, noting significantly above-average thigh and hip circumference. These figures indicate a high degree of curvature in obese lower bodies, along with a large drop value. Leveraging this data, we develop a novel slacks pattern using 3D avatars in a virtual simulation system. The formulas for the main areas of the pattern are as follows: front waist girth W/4+0.75cm+0.5cm, back waist girth W/4+0.5cm– 0.5cm, front hip girth H/4+1.25cm–0.5cm, back hip girth H/4+2cm+0.5cm, front crotch extension H/16+0.5cm, back crotch extension H/8+1cm. Results from appearance evaluations show that this pattern minimizes strain rate on the waist and hips, and its average score is significantly higher than that of an alternative pattern that was also evaluated. The minimized strain rate and high average score indicate that our pattern assigns a sufficient amount of space to the appropriate areas. Based on these results, we expect our research to inform slacks pattern development and production for obese consumers of all types.
        4,500원
        50.
        2023.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The aim of this study is to ensure the structural integrity of a canister to be used in a dry storage system currently being developed in Korea. Based on burnup and cooling periods, the canister is designed with 24 bundles of spent nuclear fuel stored inside it. It is a cylindrical structure with a height of 4,890 mm, an internal diameter of 1,708 mm, and an inner length of 4,590 mm. The canister lid is fixed with multiple seals and welds to maintain its confinement boundary to prevent the leakage of radioactive waste. The canister is evaluated under different loads that may be generated under normal, off-normal, and accident conditions, and combinations of these loads are compared against the allowable stress thresholds to assess its structural integrity in accordance with NUREG-2215. The evaluation result shows that the stress intensities applied on the canister under normal, off-normal, and accident conditions are below the allowable stress thresholds, thus confirming its structural integrity.
        4,300원
        51.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 유연근무제 관련 공무원 인식조사를 활용하여 다음 두 가지의 주요 목적 을 위한 통계적 분석을 수행하고자 한다. 첫째, 유연근무제 활용 만족도 수준과 조직 만족도 수준 간의 영향 관계를 정량적으로 검증하는 것이다. 둘째, 유연근무제 활용 만족도와 조직만족도 수준 간의 영향 관계에서 공무원의 성별과 연령이 갖는 조절효 과를 분석하는 것이다. 본 연구의 목적 달성과 가설 검증을 위해 우리나라 D 자치단체 공무원을 대상으로 설문조사를 수행하였다. 응답자 공무원의 소속은 D 자치단체 본 청, 직속기관, 산하기관, 사업소 등이 포함되었으며, 정규직 신분의 지방직 공무원이 다. 기초통계분석, 상관관계분석과 더불어 본 연구의 가설 검증을 위해 회귀분석을 수 행하였다. 분석 결과, 유연근무제 활용 만족도 수준과 조직만족도 수준 간은 통계적 으로 유의미한 양의 관계가 있음이 검증되었다. 또한, 공무원의 성별과 연령대 변수 모두 유연근무제 활용 만족도 수준과 조직만족도 간의 관계를 유의미하게 조절하는 효과가 있음이 검증되었다. 특히, 성별과 유연근무제 활용 만족도의 상호작용항과 연 령대와 유연근무제 활용 만족도의 상호작용항의 회귀계수가 모두 통계적으로 유의 미하게 나타난 점은 정부조직의 유연근무제 활용과 정책 집행에 있어 중요한 시사점 이 있다고 판단된다. 본 연구를 통해서 지금까지 유연근무제 활용 여부 자체에 대한 효 과 검증에 치우쳐 있던 국내 공공기관 대상 유연근무제 연구의 이론적 확장이 이루어 지길 기대한다. 유연근무제 이용 여부 자체에서 벗어나 유연근무제 활용 만족도 수준 이 여러 다양한 조직결과변수들에 미치는 효과를 검증함으로써 국내 공공부문 유연 근무제 연구는 더욱 더 다양하고 심도있게 추진될 수 있을 것으로 기대한다. 아울러, 정부조직에서의 유연근무제의 보다 합리적인 정착과 적극적인 활용이라는 실무적 관점에서 본 연구에서 제시하고 있는 통계분석 결과가 이에 기여할 수 있을 것이다.
        6,000원
        52.
        2023.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A transfer cask serves as the container for transporting and handling canisters loaded with spent nuclear fuels from light water reactors. This study focuses on a cylindrical transfer cask, standing at 5,300 mm with an external diameter of 2,170 mm, featuring impact limiters on the top and bottom sides. The base of the cask body has an openable/closable lid for loading canisters with storage modules. The transfer cask houses a canister containing spent nuclear fuels from lightweight reactors, serving as the confinement boundary while the cask itself lacks the confinement structure. The objective of this study was to conduct a structural analysis evaluation of the transfer cask, currently under development in Korea, ensuring its safety. This evaluation encompasses analyses of loads under normal, off-normal, and accident conditions, adhering to NUREG-2215. Structural integrity was assessed by comparing combined results for each load against stress limits. The results confirm that the transfer cask meets stress limits across normal, off-normal, and accident conditions, establishing its structural safety.
        4,600원
        53.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Abstract Purpose : This study sought to identify ways to develop the Korean optometrists to meet the diverse and growing social demand for eye health services. Methods : We analyzed the optometrist qualification system, scope of practice, educational qualifications, and types of qualifications in 38 OECD countries based on the World Health Organization (WHO) and the European Union (EU) national occupational classifications of health care professions, data from World Council of Optometry (WCO) member countries, International Orthoptics Association (IOA), and databases of laws and occupational regulations in each country. Results : The occupational classification of the WHO and EU was classified into optometrists and dispensing opticians systems at the same level as medical personnel. However, the occupational classification in Korea is operating in a lower and monotonous structure. More than 78% of OECD countries operated optometrists system, and more than 67% of optometrists performed Category 3 or higher tasks, including prevention and management of abnormal visual function and primary screening and diagnosis of eye health. The educational level of optometrists was found to have a bachelor's degree or higher education than a bachelor's degree in more than 72% of countries. In addition, major overseas countries appeared to be developing into a system of subdivided qualification types such as orthoptist, advanced optometrist, therapeutic optometrist, independent prescribing optometrist, and ophthalmic medical technicians based on the optometrists system, essential clinical experience, and additional specialized education. Conclusion : The Korean optometrists system should introduce the international level as a national qualification, expand the scope of work to Category 3, and develop more specialized and subdivided qualifications. In conclusion, Korean optometrists need to have a standardized curriculum based on international standards, a bachelor's degree or higher, and certification with required clinical experience. Key words : Korean optometrist, Optometrist, Vision care Authors
        4,200원
        54.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Korean military has sought to build an all-round military force against the national and international security environment and future asymmetric threats as well as the military threats it faces. However, while raising the need for timely electrification, there are few cases of quantitatively evaluating the loss when electrification is delayed, making it difficult for our military to provide a logical basis to support the importance of the electrification period. Therefore, through this study, we tried to analyze the index of loss cost that can support the need for timely electrification with logical and quantitative data and present it as a logical basis. To this end, the loss cost was calculated in terms of combat efficiency, equipment utilization rate, and maintenance requirements, which can be quantitatively calculated based on “combat readiness,” a general impact on the military in case of delayed timely electrification.
        4,000원
        55.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The 4th Industrial Revolution and the continuous development of Science and Technology have also required a speedy business promotion method in the defense industry. Advanced countries including the United States are already boldly innovating the existing high-cost and long-term acquisition system with the highest priority in weapons development to cope with the military rise of Russia and China. The Ministry of National Defense and the Defense Acquisition Program Administration have also recently introduced a quick acquisition system and are applying it to business promotion. In addition, some small-scale projects and weapons systems are being reorganized so that they can be managed by the units demanding them. After an organizational diagnosis of the Project Acquisition Group by the Ministry of National Defense in 2020, it has been reassigned as a subordinate unit of the Army Logistics Command from a direct unit managed by the Army HQ. As a result, problems such as work conflict or redundancy have been identified. In addition, a system has been implemented to shorten the acquisition period by applying a rapid acquisition program in the field of weapons systems by benchmarking the rapid acquisition program of advanced countries. The force support system project process will also need to introduce such a quick acquisition system. In addition, the Ministry of National Defense is considering ways to delegate some weapon systems to each military, which will then carry out tasks ranging from requirements determination to project management. Accordingly, it is now time to expand the organization for the management of the Army's weapons system acquisition project. Therefore, in this paper, the Army Project Acquisition Group was analyzed on its organization, acquisition procedures, and cooperation systems, with presentations of development plans for each field.
        4,000원
        56.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research, a new Test and Evaluation (T&E) procedure for defense AI systems is proposed to fill the existing gap in established methodologies. This proposed concept incorporates a data-based performance evaluation, allowing for independent assessment of AI model efficacy. It then follows with an on-site T&E using the actual AI system. The performance evaluation approach adopts the project promotion framework from the defense acquisition system, outlining 10 steps for R&D projects and 9 steps for procurement projects. This procedure was crafted after examining AI system testing standards and guidelines from both domestic and international civilian sectors. The validity of each step in the procedure was confirmed using real-world data. This study's findings aim to offer insightful guidance in defense T&E, particularly in developing robust T&E procedures for defense AI systems.
        4,000원
        57.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Reproductive management practices play crucial roles to maximize the reproductive performance of cows, and thus contribute to farm profitability. We aimed to assess the reproductive management of cows currently practiced in the dairy farms in an urban farming system. Methods: A total of 62 dairy farms were randomly selected considering all size of farms such as small (1-5 cattle), medium (6-20 cattle) and large farms (> 20 cattle) from selected areas of Dhaka city in Bangladesh. The reproductive managementrelated parameters viz. estrus detection, breeding method, pregnancy diagnosis, dry cow and parturition management, vaccination and treatment of reproductive problems etc. were obtained in a pre-defined questionnaire during the farm visit. Results: The visual observation method was only used (100.0%; 62/62) for estrus detection irrespective of size of the farms; while farmers observed cows for estrus 4-5 times a day, but only for 20-60 seconds each time. Regardless of farm size, 89.0% (55/62) farms used artificial insemination (AI) for breeding the cows. Intriguingly, all farms (100.0%) routinely checked the cows for pregnancy at 35-40 days post-breeding using rectal palpation technique by registered veterinarian. However, only 6.5% (4/62) farms practiced dry cow management. Notably, all farms (100.0%) provided nutritional supplements (Vit D, Ca and P) during late gestation. However, proper hygiene and cleanliness during parturition was not practiced in 77.4% (48/62) farms; even though 96.7% (60/62) farms treated cows by registered veterinarian for parturition-related problems. Conclusions: While farmers used AI service for breeding and timely check their cows for pregnancy; however, they need to increase observation time (30 minutes/ observation, twice in a day: early morning and early night) for estrus detection, consider dry cow management and ensure hygienic parturition for maximizing production.
        4,000원
        58.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the evaluation items related to the effectiveness evaluation of the LVC (Live, Virtual, Constructive) training system of the Air Force were derived and the weights of each item were analyzed. The LVC training system evaluation items for AHP (Analytic Hierarchy Process) analysis were divided into three layers, and according to the level, 3 items were derived at level 1, 11 items at level 2, and 33 items at level 3. For weight analysis of evaluation items, an AHP-based pairwise comparison questionnaire was conducted for Air Force experts related to the LVC training system. As a result of the survey, related items such as (1) Achievement of education and training goals (53.8%), (1.2) Large-scale mission and operational performance (25.5%), and (1.2.1) Teamwork among training participants (19.4%) was highly rated. Also, it was confirmed that the weights of evaluation items were not different for each expert group, that is, the priority for importance was evaluated in the same order between the policy department and the working department. Through these analysis results, it will be possible to use them as evaluation criteria for new LVC-related projects of the Air Force and selection of introduction systems.
        4,000원
        59.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to propose an operational concept for a ship in a fleet equipped with an interceptor missile system, a naval surface to air defense system, and to develop a simulation program that reflects it. The results of the defense activities of other ships in the fleet can be reflected by receiving information about the status of the enemy missiles. The allocation of defensive assets is based on the survival probability of the ship, not on the destruction of enemy attacks, which can be obtained as the product of the expected survival probability for each enemy missile. In addition, the concept of predicted survivability was introduced to assess the loss of future defense opportunities that would result from assigning a new command. A simulation program was also developed as a tool for realizing the proposed concept of operations, which generated cases.
        4,000원
        60.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we present a case study of developing MVIS (Machine Vision Inspection System) designed for exterior quality inspection of stamping dies used in the production of automotive exterior components in a small to medium-sized factory. While the primary processes within the factory, including machining, transportation, and loading, have been automated using PLCs, CNC machines, and robots, the final quality inspection process still relies on manual labor. We implement the MVIS with general- purpose industrial cameras and Python-based open-source libraries and frameworks for rapid and low-cost development. The MVIS can play a major role on improving throughput and lead time of stamping dies. Furthermore, the processed inspection images can be leveraged for future process monitoring and improvement by applying deep learning techniques.
        4,000원
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