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        검색결과 405

        1.
        2024.04 구독 인증기관·개인회원 무료
        해양 부유식 구조물의 계류시설에 대한 연구는 다양한 계류 시스템의 개발과 그 효율성에 대해 지 속적으로 연구되어 왔다. 계류 시스템은 구조물의 안전성, 내구성, 그리고 환경적인 책임을 모두 고려 해야하는 복합적인 설계 요소이다. 기존 계류바익은 해저지반의 특성에 크게 의존하며, 넓은 점유 면 적으로 인해 해양환경과 활동에 부정적인 영향을 줄 수 있다. 이러한 기존 계류시스템의 한계와 문제 점에 대응하기 위해, 본 연구에서는 새로운 계류시스템을 제안하고자 한다. 제안된 계류시스템은 계류 선이 해저지반에 고정되지 않고 중력식 기초 구조물을 거쳐 중간부력재에 연결된다. 중간 부력재는 상 시 과잉 부력상태로 상향력이 작용하며, 이로인해 계류선에 초기장력이 유도되며 전체 시스템에 강성 을 도입한다. 전체적으로 Semi-taut과 유사한 방식으로 계류 장력 변화에 따른 상단 플랫폼의 운동 제어와, 중간 부력재와의 상호연계 거동효과로 추가적인 동적 응답 저감이 기대된다. 본 연구에서는 제안된 신형식 계류시스템의 역학적 거동특성을 수치해석적으로 구현하고 파랑에 대한 Catenary system 대비 운동 저감 성능을 검증하였다.
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study developed an IoT-based agricultural well control system and demonstrated it through a control system in the current state of domestic open-field smart farms where systematic management is insufficient due to the difficulty of collecting accurate data such as agricultural water intake and usage. As a result, it was possible to derive the optimal control system test results according to the watering conditions for each schedule by conducting automatic control focusing on periods when there is no precipitation. This means that irrigation can be carried out smoothly during the time when irrigation is needed to improve crop quality and secure farm income, and as a result, it is possible to systematically manage and operate among demonstration farms connected to irrigation, resulting in a shortage of agricultural water and a resolution of supply imbalances.
        4,000원
        3.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For motor controller designers, building a simulation environment is not a difficult process. After verifying the controller by simulation, it is common to select 20kHz for the current control loop, 1kHz for the speed loop, and 100Hz for the position loop when implementing the actual HW embedded system. This is because maximized cycles (20kHz) for each control loop are unnecessary in control theory and are a waste of cost and HW resources. However, in a simulation environment, each loop will often have the same control cycle (20kHz maximum). This is because we think it is unnecessary to reflect this part in the simulation. In this paper, it is shown that the difference in the sampling time of each control loop makes a big difference in the simulation result, and as a solution, it is proposed to apply LPF to the position loop output stage. In the process, the reasons for the differences were analyzed, and the effect of LPF, the reason for application, and the feasibility of implementation were proved by actual software coding.
        4,000원
        5.
        2023.11 구독 인증기관·개인회원 무료
        The Nuclear Export and Import Control System (NEPS) is currently in operation for nuclear export and import control. To ensure consistent and efficient control, various computational systems are either already in place or being developed. With numerous scattered systems, it becomes crucial to integrate the databases from each to maximize their utility. In order to effectively utilize these scattered computer systems, it is necessary to integrate the databases of each system and develop an associated search system that can be used for integrated databases, so we investigated and analyzed the AI language model that can be applied to the associated search system. Language Models (LM) are primarily divided into two categories: understanding and generative. Understanding Language Models aim to precisely comprehend and analyze the provided text’s meaning. They consider the text’s bidirectional context to understand its deeper implications and are used in tasks such as text classification, sentiment analysis, question answering, and named entity recognition. In contrast, Generative Language Models focus on generating new text based on the given context. They produce new textual content continuously and are beneficial for text generation, machine translation, sentence completion, and storytelling. Given that the primary purpose of our associated search system is to comprehend user sentences or queries accurately, understanding language models are deemed more suitable. Among the understanding language models, we examined BERT and its derivatives, RoBERTa and DeBERTa. BERT (Bidirectional Encoder Representations from Transformers) uses a Bidirectional Transformer Encoder to understand the sentence context and engages in pre-training by predicting ‘MASKED’ segments. RoBERTa (A Robustly Optimized BERT Pre-training Approach) enhances BERT by optimizing its training methods and data processing. Although its core architecture is similar to BERT, it incorporates improvements such as eliminating the NSP (Next Sentence Prediction) task, introducing dynamic masking techniques, and refining training data volume, methodologies, and hyperparameters. DeBERTa (Decoding-enhanced BERT with disentangled attention) introduces a disentangled attention mechanism to the BERT architecture, calculating the relative importance score between word pairs to distribute attention more effectively and improve performance. In analyzing the three models, RoBERTa and DeBERTa demonstrated superior performance compared to BERT. However, considering factors like the acquisition and processing of training data, training time, and associated costs, these superior models may require additional efforts and resources. It’s therefore crucial to select a language model by evaluating the economic implications, objectives, training strategies, performance-assessing datasets, and hardware environments. Additionally, it was noted that by fine-tuning with methods from RoBERTa or DeBERTa based on pre-trained BERT models, the training speed could be significantly improved.
        6.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cars using diesel have always had problems with reducing exhaust fumes, and have been studied steadily in this regard. There were studies on the remanufacturing effect of DOC catalyst deactivated by diesel vehicle smoke reduction device, analysis of vehicle fire accident cases caused by damage to diesel vehicle smoke reduction device, and related studies on the remanufacturing effect of diesel vehicle smoke reduction device DPF. This study is also to develop an exhaust flow control unit suitable for an exhaust engine to completely burn smoke generated by an engine using a diesel engine in a low temperature exhaust gas. The main systems to be developed are high-performance heaters, burner structures that can maintain ignition in exhaust flows, and exhaust flow control units that reduce exhaust gas backflow effects caused by diesel engines.
        4,000원
        7.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        함정의 전투관리체계나 민간의 스마트 시티와 같은 많은 센서와 동작기기가 연결된 체계에서는 주로 미들웨어인 DDS(Data Distribution Service)를 사용하여 대규모의 데이터를 전송하고 향후 센서나 장비 증가에 대해 효과적으로 대응하고 있다. 선박에서 함정의 전투관리체계(Combat Management System, CMS)와 같은 역할을 하는 중요한 제어체계인 통합기관감시제어체계(Engineering Control System, ECS)는 여전히 Server-Client 모델을 기반으로 산업용 프로토콜(Modbus, CAN(Controller Area Network) bus 등)을 사용하여 데이터를 전송하고 있어 확장성 측면에서 불리하다. 따라서 향후 자동화나 무인화가 진행될 경우에 많은 센서류가 추가될 것이며 이는 많은 프로그램 수정 소요가 발생하게 되며, DDS는 이러한 상황에서 좋은 해결책이 될 수 있다. 본 연구에서는 전투관리체계에서 사용 중인 미들웨어인 DDS 중에서 OMG(Object Management Group) 표준을 따르는 OpenDDS를 활용하여 선박의 통합기관감시제어체계의 개발 가능성을 확인하였다. 이를 위해 필드장비 시뮬레이터 및 ECS 서버를 구성하여 DDS를 이용한 필드장비 데이터 입출력 시뮬레이션을 수행하였다. 개발한 ECS 축소모형은 데이터를 발간-구독하는데 문제가 없으며, DDS가 선박 ECS의 미들웨어로 충분히 사용할 수 있을 것으로 판단된다.
        4,000원
        10.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research introduced a command-filtered backstepping control of mirror system to maintain laser communication between satellite and ground station. This requires a 2 degree of freedom gimbal mirror system using DC motors for target acquisition, pointing, and tracking (APT) system. This APT system is used for laser communication between satellite and ground stations. To track these desired angles, we have to control DC motors using introduced command-filtered backstepping controller (CFBSC) with disturbance. Command filtered backstepping controller has second order filter instead differentiation for simple and fast calculation. Introduced command-filtered backstepping control gives a smooth control signal for intermediate states. Simulation results verify that CFBSC outperforms SMC in terms of tracking error and disturbance rejection.
        4,000원
        11.
        2023.05 구독 인증기관·개인회원 무료
        A vitrification facility control area is formed to control and monitor the vitrification facility process, and the control system is designed to manage the vitrification facility more safely and effectively. The control system is largely composed of a process control system and an off-gas monitoring system. The process control system is operated so that operation variables can be maintained in a normal state even in normal and transient conditions, and is designed so that the vitrification facility can be stably maintained in the event of an abnormality in the facility. The process control system consists of Programmable Logic Controller (PLC) and Local Control Panel (LCP), which controls and monitors each unit device. In addition, operation variables are provided to the operator so that the operator can manage operation variables during process control in a centralized manner for the operation of the vitrification facility. The off-gas monitoring system is operated to monitor whether the off-gas discharged to the environment is stably maintained within the standard level, and the off-gas is monitored through an independent monitoring system.
        12.
        2023.05 구독 인증기관·개인회원 무료
        The Nuclear Safety and Security Commission (NSSC) and the Korea Institute of Nuclear Nonproliferation and Control (KINAC) operate the Nuclear Export and Import Control System (NEPS), an online comprehensive export and import control management system to guide the domestic nuclear export and import control regime and efficiently process the application, processing, and issuance of various civil complaints required for compliance. This paper analyzes the results of NEPS functional improvements made in 2022. First, NSSC and KINAC launched a nuclear plant technology follow-up system. Since establishing the Nuclear Plant Technology Export License (Plant License) system in 2015, large-scale nuclear power plant projects with a large amount of technology transfer have been issued a Plant License, allowing them to transfer technology without a separate individual export license. The recipient of a Plant License is not required to obtain an additional export license but to follow up on the transferred technology, such as checking whether it is a strategic technology and reporting quarterly transfer details. A dedicated system has been established to facilitate the follow-up of plant license projects. That has improved work efficiency for both the regulated and the regulator. Second, we have improved the procedures for retrieving and supplementing civil petitions. We added a function allowing civil petitioners to directly retrieve a civil petition to cancel a previously filed civil petition or to revise it themselves. In addition, we improved the procedure for supplementing a civil petition by setting a supplementation deadline for a reviewer’s request to modify a civil petition and sending a reminder before the expiration of the supplementation deadline. That enhances the convenience of the complainant and the examiner. Finally, we have changed the numbering system for export and import control reviews. Previously, the application number was a 15-digit system with an 8-digit date and 7-digit serial number. We have simplified the number by changing the three unused digits in the serial number to a single symbol that separates the type of application. That made it possible to utilize the number for relevant searches in the future. Also, simplifying the number has improved the efficiency of applying, processing, and consulting for civil affairs. In the future, NSSC and KINAC will continue to upgrade NEPS and make various functional improvements, and there will be many changes in system operation through cloud transfer in a few years.
        13.
        2023.05 구독 인증기관·개인회원 무료
        About 83% of the information systems of administrative and public agencies are operated by agencies, and most of them are vulnerable to security due to the small scale of operation, insufficient facilities, and lack of dedicated personnel. To address these issues, the Ministry of the Interior and Safety announced in June 2021 that, as part of the “Second Basic Plan for E-Government,” all information systems of administrative and public agencies will be converted to a cloud-based integrated management operating environment by 2025 to provide stable public services. Accordingly, relevant laws and guidelines should be researched and analyzed to prepare for the cloud conversion of the Nuclear Export and Import Control System (NEPS) operated by the Export and Import Control Office of the Korea Institute of Nuclear Nonproliferation and Control (KINAC). The Cloud Computing Act defines cloud computing, establishes a basic plan and implementation plan, provides support for promoting the adoption of cloud computing by state institutions, supports the construction of integrated information and communication facilities based on cloud computing technology, provides cost and technical support, and regulates cloud security certification, and applies the Personal Information Protection Act and the Act on Promotion of Information and Communication Network Utilization and Information Protection to protect personal information. The E-Government Act defines integrated standards and principles for information resources, support for the use of cloud computing services, classification standards for information resources, and integrated standards for calculating the size and capacity of information systems. The Notice on Standards for Using Cloud Computing Services and Securing Safety for Administrative Agencies and Public Institutions specifies the standards for using cloud computing services and measures to secure stability for administrative agencies, contracts for using cloud computing services, and ensuring continuity of cloud computing services. The Basic Guidelines on National Information Security stipulate the establishment and implementation of security measures, system security, user security, security management, information and communication network security separating internal network and internet network, and cloud computing security measures, and stipulate the NIS security review when introducing private cloud services. In order to convert NEPS to the cloud computing services, network, and software design plans, transfer plans, and cloud operation plans will be established in compliance with the relevant laws and guidelines. And future research will include researching the system status of major public and private cloud service providers and analyzing their advantages and disadvantages.
        17.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the second-order Nomoto’s nonlinear expansion model was implemented as a Tagaki-Sugeno fuzzy model based on the heading angular velocity to design the automatic steering system of a ship considering nonlinear elements. A Tagaki-Sugeno fuzzy PID controller was designed using the applied fuzzy membership functions from the Tagaki-Sugeno fuzzy model. The linear models and fuzzy membership functions of each operating point of a given nonlinear expansion model were simultaneously tuned using a genetic algorithm. It was confirmed that the implemented Tagaki-Sugeno fuzzy model could accurately describe the given nonlinear expansion model through the Zig-Zag experiment. The optimal parameters of the sub-PID controller for each operating point of the Tagaki-Sugeno fuzzy model were searched using a genetic algorithm. The evaluation function for searching the optimal parameters considered the route extension due to course deviation and the resistance component of the ship by steering. By adding a penalty function to the evaluation function, the performance of the automatic steering system of the ship could be evaluated to track the set course without overshooting when changing the course. It was confirmed that the sub-PID controller for each operating point followed the set course to minimize the evaluation function without overshoot when changing the course. The outputs of the tuned sub-PID controllers were combined in a weighted average method using the membership functions of the Tagaki-Sugeno fuzzy model. The proposed Tagaki-Sugeno fuzzy PID controller was applied to the second-order Nomoto’s nonlinear expansion model. As a result of examining the transient response characteristics for the set course change, it was confirmed that the set course tracking was satisfactorily performed.
        4,200원
        18.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The mass-rearing system for Neodryinus typhlocybae as a biological control agent of Metcalfa pruinosa was established. Depending on the density of host nymphs and plants, the average number of cocoons produced by the parasitoids was 5-8 and 70-150 cocoons per leaf and sapling of mulberry, respectively. There is a significant difference in cocoon length between females (6.10-6.46 mm) and males (4.20-4.62 mm). Sex determination of cocoons before emergence will be helpful for efficiently releasing this parasitoid in fields. The parasitic rate of N. typhlocybae at the semi-field condition was on average 13-17%. The release number of this parasitoid did not affect parasitism. Nevertheless, the population growth rate of M. pruinosa was reduced by increasing the release number of N. typhlocybae. The parasitoid offspring’s sex and bivoltine were influenced by the host age. On young host nymphs, the bivoltine portion of parasitoid increased. When parasitized on 4th or 5th nymphs, the offspring’s female ratio of N. typhlocybae increased. This result may be useful for potentially controlling mass rearing production of parasitoid.
        4,000원
        20.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        자율운항선박(MASS : Maritime Autonomous Surface Ships)은, 고도의 자율도를 가지고, 계획된 경로를 따라 자율 운항하지만, 필요시 육상원격제어센터(SRCC : Shore Remote Control Center)에서 선박의 운항에 직접 개입할 수 있다. 본 연구에서는 이러한 자율운항 선박의 운항을 육상에서 모니터링하고 유사시 원격제어하는 역할을 담당할 육상원격제어사(SRCO : Shore Remote Control Officer)의 교육 훈련에 필요한 시뮬레이터 시스템의 운용개념과 이를 가능하게 하기 위한 요구기능에 대해 검토하였다. 육상원격제어 시뮬레이터 시 스템은, 다수의 자율운항선박의 운항상황을 모니터링하는 Monitoring Station, 유사시 특정 선박의 운항에 직접 원격개입하는 Control Station의 기능을 모의하도록 하였고, 시뮬레이션 종합통제실, 자율운항선박 운항상황 모의 시뮬레이터, 그리고 주변의 유인선 운항을 모의하기 위한 통항선 시뮬레이터 등으로 구성하였다. 기능적으로는, 육상에서 선박을 직접 제어하기 위하여 원격으로 개입하는 ESRC(Emergency Situation for Remote Control) 상황을 정의하여 이러한 상황을 모의할 수 있도록 하였다.
        4,000원
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