• Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.278-283
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• 2010

Black plaice, Pleuronectes obscurus (Herzenstein), were collected and fertilized to observe egg development, temperature-related cleavage rates, and mitotic intervals (${\tau}_0$). Fertilized egg was demersal, adhesive, and did not contain oil globules. After 1.75 h, the blastodisc formed, and hatching took place 121 h after fertilization at $14^{\circ}C$. The hatched larvae were $3.5{\pm}0.16\;mm$ in total length. At higher temperatures, eggs developed faster and underwent further identical developmental processes. Additionally, ${\tau}_0$ and water temperature were strongly negatively correlated at all temperatures (Y=-2.6981X+98.767, $R^2$=0.9831, where Y is ${\tau}_0$, and X is temperature) for black plaice.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.33-37
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• 2001

Recently, the HFPD measurement testing is widely used in partial discharge measurement of HV machines because HFPD measurement testing receives less influence of external noise and has a merit of good sensitivity. Also HFPD testing is able to offer the judgement standard of degradation level of HV machine and can detect discharge signals in live-line. Therefore it is very useful method compare to previous conventional PD testing method and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• Journal of Drive and Control
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• v.14 no.3
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• pp.50-57
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• 2017

Recently, methods of verification for electro-hydraulic servo controllers are various and the required number of testing controllers is continuously increasing in some specific systems. In this study, a PCB-based electronic simulator of hydraulic actuators is designed and developed to simplify test set-up for controllers and to facilitate alteration for characteristics of the simulator. Several features to reduce required time and manpower for verifying controllers are described. Especially, the simulator is considerably efficient to examine some controllers for different hydraulic actuators in a test. Response characteristics of the simulator are compared with those of real actuators to demonstrate validity of this method. Results reveal utilizing the designed simulator for inspecting controllers is equally effective as using hydraulic actuators.

• Electronics and Telecommunications Trends
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• v.38 no.1
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• pp.26-35
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• 2023

Inkjet printing is a typical printing technology with many advantages, such as material cost reduction, noncontact pattern formation without a mask, and process simplification. With the recent and rapid development of ink materials, parts and equipment, and process technologies related to inkjet printing, it is becoming a major process in various areas of the display industry. In particular, for the QD-OLED (quantum dot-organic light-emitting diode) display announced by Samsung Display in 2022, quantum dot pixel production by applying inkjet printing is a key technology. We analyze inkjet printing technology for mass production applied to the display industry and discuss the technology development trends in academia and industry toward the realization of next-generation displays.

• Korean Journal of Human Ecology
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• v.17 no.4
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• pp.661-677
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• 2008

The purpose of this study is to develop the playground environment model for child care center by analyzing user needs of playground environment. To systemize the playground environment design factors and guidelines, we reviewed the previous research, actual measurement and observation were used as the research methodology. And to recognize the needs of users, the survey and picture survey was conducted to the staffs and children. The scope of survey included child care centers in Seoul and Daejeon, ultimately selecting 12 places in Seoul and 13 places in Daejeon. In terms of the survey period, actual measurement was conducted from June of 2006 to February of 2007, survey and picture survey was conducted from August to September of 2006. For analysis, we used SPSS 10.0 to check the frequency and percentage, as well as to perform cluster analysis. The findings of research can be summarized as below: 1. In playground environment, we observed the area of play ground and ground cover, the independence of play area, play equipment, and the composition of play area. The result of observation showed that while playground area varied widely, ground cover, play equipment, and the composition of play area turned out to be identical, regardless of the playground's area. Therefore, in order to classify various playground environments, we categorized them into 5 types, using the number of children and the area of play ground as a category. Type A had large facilities and small playground area. Type B had small sized facilities and large playground area. Type C had medium sized facilities and small playground area. Type D had medium sized facilities but large playground area. Type E had large sized facilities and large playground area. 2. On the other hand, staffs wanted a tunnel, playhouse, comprehensive play equipment, and a maze to be installed as play facilities, and there were requests for adventure play area and carpenter play area. The picture survey to children showed that they wanted equipments that can provide more thrill, adventure and challenge to them than the ones they see now. Therefore, existing child care center play environments must change from the monotonous and identical environments to the ones that can provide diversities, challenges, and adventures. In the contexts of 5 playground types suggested by this research, type B and D, E where the area of playground were larger than the legally required, should include various play areas and install appropriate play equipments and facilities. Type A and C where the area were small, should provide multipurpose play area to attract the various play behaviors of children.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.319-334
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• 2009

This paper describes an overview of technology and research of dam and levee in Korea. In order to trace the development of dam and levee construction technology, history of design and construction of them is briefly reviewed, and their statistics including type, number and purpose of those hydraulic structures in Korea are dealt with. Furthermore, current status of research on the mentioned structures is also reviewed based on the papers published in Korean societies such as Korean Society of Civil Engineers and Korean Geotechnical Society. Finally state-of-the-art equipment and technology to investigate the safety conditions, and hence to enhance or rehabilitate their stability and dam and levee systems, respectively, are introduced here.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.10a
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• pp.209-212
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• 2003

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2519-2528
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• 2013

The standard of estimate is being used as basic material for appropriating construction expenses of public institutions and private institutions. The present thesis aims to propose a new form of a standard of estimate and a calculation method of work amount of equipment by targeting a representative construction type selected at river reservation work. The present thesis expects that the convenience of users can be expanded by improving applicability of a standard of estimate and simplifying a calculation process of work amount of equipment in a process planning stage so that the provision of work crew lineup information and daily productivity information is possible by a standard of estimate. In case of river conservation work, because the variables called work conditions act very largely, there exists much difficulty for generalizing productivity information and work amount of equipment, but if its accuracy could be enhanced by improving continuous productivity information and work amount information of equipment, the simplification of process planning establishment and cumulative process through a standard of estimate would be possible.

• Journal of Cadastre & Land InformatiX
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• v.46 no.1
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• pp.3-21
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• 2016

This study analyzes the key factors of 3D spatial information in accordance with the establishment of aerial and ground equipment fusion, and the quality improvement solutions are delivered from the preference survey. Furthermore, it investigates the factors affecting the quality of the individual technical elements through the establishment of three-dimensional spatial information. It is for identifying the priority which needs to be improved, and this data will be used to identify the evaluation for factors, the technology development and its application. For this purpose, the presence or absence of equality is judged by the quantitative techniques through the preference survey of the gap between the experts of spatial information and survey and the general users who have experiences on 3D spatial information.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.493-500
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• 2015

The importance of the air and vessel traffic control center is increasing rapidly after the recent accident of 'Sewol ferry'. Aviation, marine, and the logistics sectors are already using monitoring and control technology widely. However, the monitoring and control system for complex and dangerous construction sites operation has yet to be employed. A monitoring/control system is required for effective communication between the control center and the construction equipment fleet at a construction site, and also the exact role that notifies accurate process and identification of hazards on construction sites as needed. Therefore, this paper presents the study about communication between the construction equipment fleet and the control center through the comparison of air traffic, marine, and logistics control systems for the development of construction equipment fleet management system.