4차 산업이 발전함에 따라 해상운송 분야에서도 자율운항선박의 연구가 진행되고 있다. 현재 2, 3단계의 자율운항선박이 운항 을 하고 있으며 육상에서 원격조종의 장비로 감시하며 상황에 따라 운항에 개입하는 육상원격제어사가 이미 활용되고 있다. 하지만 이들 의 교육과정이 국제적으로 정립되지 않아 부적격한 육상원격제어사에 의한 사고 위험성이 높아지고 있다. 본 논문에서는 육상원격제어사 에 필요한 교육을 기존의 해기사 교육 중 육상원격제어사에게 필요한 교육과 원격제어환경에서 필요한 교육으로 구성하였고 효과적인 교육의 활용을 위해 비기술적 역량교육을 포함하였다. 이러한 교육과정은 신속하게 활용될 수 있으며 역량평가를 통한 해사안전에 부합 하는 신규 육상원격제어사를 배출할 수 있다. 그리고 기존의 선원들도 육상원격제어사로 전직할 수 있는 교육을 제공할 수 있다.

The global power generation industry is becoming a key power generation industry with gas power generation and renewable energy solar power generation. This research aims to focus on solving two problems as a method to improve the solar light collection efficiency among fixed variable deformation methods. Maintaining the proper temperature of the water injection device through automatic temperature detection to solve efficiency degradation, and establishing an automatic operation system by finding the optimal angle for each season, are intended to derive a value that can represent the optimal power generation.

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.

Recently, considerable attention has been given to nickel-based superalloys used in additive manufacturing. However, additive manufacturing is limited by a slow build rate in obtaining optimal densities. In this study, optimal volumetric energy density (VED) was calculated using optimal process parameters of IN718 provided by additive manufacturing of laser powder-bed fusion. The laser power and scan speed were controlled using the same ratio to maintain the optimal VED and achieve a fast build rate. Cube samples were manufactured using seven process parameters, including an optimal process parameter. Analysis was conducted based on changes in density and melt-pool morphology. At a low laser power and scan speed, the energy applied to the powder bed was proportional to and not . At a high laser power and scan speed, a curved track was formed due to Plateau-Rayleigh instability. However, a wide melt-pool shape and continuous track were formed, which did not significantly affect the density. We were able to verify the validity of the VED formula and succeeded in achieving a 75% higher build rate than that of the optimal parameter, with a slight decrease in density and hardness.

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis (CLA), a chronic contagious disease in small ruminants. The prevalence of CLA has been reported to be >50% in Korean black goats. CLA is difficult to control due to a lack of efficient vaccines and treatment methods. Effective disinfection of the farm environment may be an alternative strategy for reducing the spread of C. pseudotuberculosis. The objective of this study was to evaluate the efficacy of commercial disinfectants against CLA. The six commercial disinfectants, largely composed of sodium dichloroisocyanurate, sodium hypochlorite, potassium monopersulfate triple salt, quaternary ammonium, citric acid, and copper sulfate, were tested against five different genotypes of C. pseudotuberculosis isolated from goat farms in Korea. Efficacy tests were performed in accordance with the disinfectant efficacy test guidelines recommended by the Animal and Plant Quarantine Agency of Korea with slight modifications. All disinfectants except for copper sulfate exhibited >99.99% killing efficacy under hard water conditions following 30 min of incubation, which is the recommended standard treatment time according to guidelines. The minimum bactericidal treatment time was evaluated by employing treatments for durations of 1, 5, and 15 min. The most effective compounds under hard water conditions were sodium dichloroisocyanurate, potassium monopersulfate triple salt, and sodium hypochlorite, exhibiting >99.99% killing efficacy after 1 min of treatment. In the aqueous solution forms, citric acid and the quaternary ammonium compound were the most effective, but required at least 5 min to kill >99.99% of the bacteria. The current study characterizes the killing efficacy of six commercial disinfectant active compounds against C. pseudotuberculosis. Thus, this study provides essential information regarding the efficacy of the disinfectants used to control CLA in goat farms.

딸기 수경재배 시 일사비례제어를 이용하여 생육단계별 적 정 누적일사량 기준을 설정하고자 수행하였다. 급액 방법은 외부 일사량을 기준으로 일정 누적 일사량에 도달하면 급액 하였고 누적 일사량 기준은 150, 200J·cm-2과 생육단계에 따 라 200J·cm-2에서 150J·cm-2로 변경하는 처리를 두었다. 타이 머 제어는 대조구로 설정하였다. 월별 평균 급액 횟수는 누적 일사량이 많은 3월에 150 J·cm-2과 생육단계별(150J·cm-2) 처 리구가 5.6회, 누적일사량이 적은 12월에 200J·cm-2과 생육 단계별(200J·cm-2) 처리구가 2.7회, 타이머는 3.6－3.8회였 다. 수분이용효율은 주당 총 급액량이 적었던 타이머 처리구 가 19.8g·L-1로 일사제어 처리구에 비해 낮았다. 일사제어에 따른 생육 및 과실 특성은 차이가 없었다. 생육단계별 처리구 가 총 상품과 수량은 주당 328g, 상품과율 85.3%로 가장 높았 다. 딸기 수경재배 시 일사비례 급액제어 방식은 재배기간 동 안 동일한 누적일사량 기준보다 생육단계별로 누적일사량을 조절하는 것이 과실의 수량 향상에 도움이 되었다.

In this study, we collect water control valves that have had accidents due to existing cracks, etc. are collected, and propose investigation items for strengthening the valve structural safety evaluation through a series of analyzes from valve specifications to physicochemical properties are proposed. The results of this study are as follows. First, there was a large variation in the thickness of the body or flange of the valves to be investigated, which is considered to be very important factor, because it may affect the safety of the valve body against internal pressure and the flange connected with the bolt nut. Second, 60% of the valves under investigation had many voids in the valve body and flange, etc. and the decrease in thickness due to corrosion was relatively large on the inner surface in contact with water rather than the outer surface. It is judged that the investigation of depth included voids is very important factor. Third, all valves to be investigated are made of gray cast iron foam, and therefore it is judged that there is no major problem in chemical composition. It is judged that the chemical composition should be investigated. Fourth, as a physical investigation item, the analysis of metal morphology structure seems to be a very important factor for nodular cast iron from rather than a gray cast iron foam water valve with a flake structure. As it was found to be 46.7~68.8% of the standard recommended by KS, it could have a direct effect on damage such as cracks, and therefore it is judged that the evaluation of tensile strength is very important in evaluating the safety of the valve.

The RPV internal structure is a high radio activated part and has very complex geometry. Therefore, it needs to be cut remotely with an automated cutting system to minimize the worker exposures. To do so, we made up the remote laser cutting system with a laser cutter, robot manipulator and control software system and the laser cutter is moved by the robot manipulator based on the command from the control software system. A laser cutter is required to keep the desired standoff position between the nozzle of the laser cutter and surface of the cut target model to cut properly. Moreover, in the remote cutting process, an exact time and sequence control of the air supply and the laser emission is required for the cutting quality and the process safety. In this study, we proposed the PERT chart-based process execution and control methodology. The PERT chart is a graph which is represented by nodes and edges. The node of the PERT chart has the information about the activity details such as activity type, execution time and related device. Using the edge we make the sequence of the desired activity execution. A PERT chart of the cutting scenario is compiled in the control software system to creates data and thread structure to operate the physical device. We built software architecture to interpret and execute the PERT chart efficiently in the digital simulation platform which enables us to use existing pre-built simulation scenario for the laser cutting process. In addition, we have tested various laser cutting test cases in our test bed to verify the performance of our system. The test bed environment has the shape of the RPV internal structure and is placed under water.

An induction melting facility includes several work health and safety risks. To manage the work health and safety risks, care must be taken to identify reasonably foreseeable hazards that could give rise to risks to health and safety, to eliminate risks to health and safety so far as is reasonably practicable. If it is not reasonably practicable to eliminate risks to health and safety, attention have to be given to minimize those risks so far as is reasonably practicable by implementing risk control measures according to the hierarchy of control in regulation, to ensure the control measure is, and is maintained so that it remains, effective, and to review and as necessary revise control measures implemented to maintain, so far as is reasonably practicable, a work environment that is without risks to health or safety. The way to manage the risks associated with induction melting works is to identify hazards and find out what could cause harm from melting works, to assess risks if necessary – understand the nature of the harm that could be caused by the hazard, how serious the harm could be and the likelihood of it happening, to control risks – implement the most effective control measures that are reasonably practicable in the circumstances, and to review control measures to ensure they are working as planned.