• Spatial Information Research
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• v.10 no.3
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• pp.455-468
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• 2002

Toward the systematic and efficient management of national land, National Geography Institute(NGI, National mapping agency) has been producing national basemap in automated process since middle of 1980's. Under the National Geographic Information System(NGIS) Development Plan, NGI began to produce digital maps in the scales of 1:1,000, 1:5,000, 1:25,000 since 1995. However, those of digital maps that have been generated under NGIS Development Plan need to be modified and corrected due to lack of technology and experience in making digital maps. In this context, those digital maps generated are currently in great need for improving the data dictionary. It is fully appreciated in previous research that data dictionary will be a key element far users and generators of digital maps to rectify the existing problems in digital maps as well as to maximize the application of digital maps. In this paper, we analyzed existing problems in digital maps based on previous researches and interviews with engineers in different fields of geospatial engineering. And then, the existing data dictionary has been redefined and modified. In the line of modification process, a relational matrix was established fur each topographic feature defined in the existing feature classification system. This paper presents newly proposed data dictionary which conforms to newly defined feature classification system from previous research performed by NGI.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.4
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• pp.343-352
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• 2013

In this study, a smooth flat surface, low fin, Turbo-B, and Thermoexcel-E surfaces are used to examine the effect of the flow velocity on the pool boiling heat transfer coefficients (HTCs) and critical heat fluxes (CHFs). HTCs and CHFs are measured on a smooth square heater of $9.53{\times}9.53mm^2$ at $60^{\circ}C$ in a pool of pure water at various fluid velocities of 0, 0.1, 0.15, and 0.2 m/s. Test results show that for all surfaces, CHFs obtained with flow are higher than those obtained without flow. CHFs of the low fin surface are higher than those of the Turbo-B and Thermoexcel-E surfaces due largely to the increase in surface area and sufficient fin spaces for the easy removal of bubbles. CHFs of the low fin surface show even 5 times higher CHFs as compared to the plain surface. On the other hand, both Turbo-B and Thermoexcel-E surfaces do not show satisfactory results because their pore sizes are too small and water bubbles easily cover them. At low heat fluxes of less than $50kW/m^2$, HTCs increase as the flow velocity increases for all surfaces. In conclusion, a low fin geometry is good for application to steam generators in nuclear power plants.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.126-133
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• 2005

Securing of radioactive waste disposal site and the related operations for disposal of low and intermediate level radioactive waste is being actively carried out in Korea. For disposal of radioactive wastes, physicochemical and radiological status and integrity of radioactive wastes must be secured first. Also, waste generators must provide this information to disposers. In addition, to secure the safety of waste disposal, waste acceptance criteria (WAC) and site specific waste acceptance criteria (SWAC) to consider characteristics of the disposal site are required. Radioactive wastes must be processed, generated, managed and transferred in accordance with these criteria. [1] For this, evaluation of properties on each of the radioactive wastes must be performed. However, in reality, atomic power plants are experiencing difficulties in relation to this due to the large quantity of radioactive waste generation. In order to solve this problem, IAEA and major overseas countries have developed, thus are using waste certification program (WCP) and quality assurance program (QAP) [2,3]. On the basis of these programs, radioactive waste certification program has been developed for safe disposal of radioactive wastes in Korea to satisfy the provisions specified in 'low and intermediate level radioactive waste transfer guidelines' of announcement No. 2005-18 from the Ministry of Science and Technology and specific site waste acceptance criteria (tentative plan). In addition, it is being planned to administer amendment on commercial atomic power plant related procedures and ensile staff training in order for early introduction and operation of radioactive waste certification system.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.135-142
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• 2015

Human-powered self-generating devices have been attractive with its operation characteristic independent from outer environment such as weather condition and wind speed. However, conventional self-generators have low electric power output due to their weakly-coupled electromagnetic structure. More importantly, rotary crank motion which is usually adopted by conventional self-generator to generate electricity requires specific skeletal muscles to maintain large torque circular motion and consequently, causes fatigue on those muscles before it can generate enough amount of electricity for any practical application. Without improvement in electric power output and usability, the human-powered self-generator could not be used in everyday life. This study aims to develop a human-powered self-generator which realized a strong electromagnetic coupling in a closed-loop tubular structure (hula-hoop shape) for easy and steady long-term driving as well as larger electric output. The performance and usability of the developed human-powered generator is verified through experimental comparison with a commercial one. Additionally, human workload which is a key element of a human-powered generator but not often considered elsewhere, is estimated based on metabolic energy expenditure measured respiratory gas analyzer. Further study will focus on output and portability enhancement, which can contribute to the continuous power supply of mobile equipments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.174-180
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• 2020

This paper presents the development of a tacho generator that is applicable to a DC motor for anti-aircraft weapon systems. In general, devices such as tacho generators and resolvers are used as feedback devices for controlling DC motors. A tacho generator with a wide operating temperature range was developed, which has robust characteristics against shock loads and vibrations according to the operational characteristics of anti-aircraft weapon systems. The target specifications were set based on the requirements of the tacho generator currently in operation. A rotor coupled to the shaft of the motor and a stator coupled to the housing of the motor were then designed and manufactured. The inductance was 31.0 mH, the terminal resistance was 147.7 ohms, and the rotational measurement factor was satisfactory under both normal operation and operating conditions after the maximum speed for the standard of 9.500 ± 0.475 V/krpm. In addition, the environmental suitability of the applied equipment was confirmed through the rate of change in unit temperature, and it was found that the temperature characteristics were all within 0.03 %/℃.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.659-666
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• 2006

Servo-motors are used as key components of automated system by performing precise motion control as accurate positioning and accurate speed regulation in response to the commands from computers and sensors. Especially, the linear brushless servo-motors have numerous advantages over the rotary servo motors which have connection with the friction induced transfer mechanism such as ball screws, timing belts, rack/pinion. This paper proposes an estimation method of unknown motor system parameters using the informations from the sinusoidal driving type linear brushless DC motor dynamics and outputs. The estimated parameters can be used to tune the controller gain and a disturbance observer. In order to meet this purpose high performance Digital Signal Processor, TMS320F240, designed originally for implementation of a Field Oriented Control(FOC) technology is adopted as a controller of the liner BLDC servo motor. Having A/D converters, PWM generators, rich I/O port internally, this servo motor application specific DSP play an important role in servo motor controller. This linear BLDC servo motor system also contains IPM(Intelligent Power Module) driver and hail sensor type current sensor module, photocoupler module for isolation of gate signals and fault signals.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.179-184
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• 2019

In many countries, such as developing countries where electricity is scarce, small wind turbines in the form of Off Grid are an effective solution to solve power supply problems. In some countries, the expansion of power systems and the decline of electricity-intensive areas have led to the use of small wind power in urban road lighting, mobile communications base stations, aquaculture and seawater desalination. With this change, the size of the small wind power industry is expected to have greater potential than large-scale wind power. In the case of small wind power generators, the generator is controlled at a variable speed, and the voltage and current generated by the generator have many harmonic components. To solve this problem, the AC to DC converter to be studied in this paper is a three-phase step-up type converter with a single switch. The inductor current is controlled in discontinuous mode, and has a characteristic of having a unit power factor by eliminating the harmonic of the input current. The proposed converter is composed of LCL filter and three phase rectification boost converter at the input stage and a single phase full bridge for grid connection. It is a control system with energy storage system(ESS) that the system stabilization can be pursued against the electric power.

• Journal of Korean Society for Quality Management
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• v.52 no.3
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• pp.575-591
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• 2024

Purpose: Storage furniture in a laboratory where chemical experiments are conducted should satisfy both the chemical reactivity and stability required in the experimental environment, commonality with general households, and economic feasibility for the mass production system. Therefore, the development of storage furniture used in the laboratory should be done quickly through a process verified by utilizing various ideas and using a method suitable for the special environment called the laboratory. This study deals with the process of developing materials for inner drawers of laboratory furniture that meet these requirements. Methods: TRIZ methodology and ARIZ-85C process were applied to satisfy the requirements arising from the product development process, ARIZ process was applied step by step to resolve the contradictions that occurred during the development process, and 40 invention principles and ideal solutions (Ideal Final Results: IFR) were derived through clear analysis of the problem to select materials suitable for the special environment of the laboratory. Results: This study focused on the selection of materials that meet the durability and chemical stability required in the special environment of laboratory furniture. Through this, various solutions were sought with the aim of reducing cost and increasing productivity, and the process of maximizing useful functions and minimizing irrational parts in use was focused on TRIZ's contradiction resolution method. As a result, we found a way to improve the performance and efficiency of laboratory furniture through the selection of optimized furniture materials and problem solving methods. Conclusion: In this study, a methodology for the development of efficient and safe laboratory furniture materials was found and verified. In the use of furniture products in a laboratory, corrosion or damage caused by chemical generators may occur, making it difficult to use as a product. As a result, a method to reduce cost and increase productivity while maintaining the durability and chemical stability of laboratory furniture was found, and by finding a solution to the two relationships between chemical safety and production efficiency in the process of selecting materials for optimized furniture materials, and applying the ARIZ development process, the effectiveness of the product development process in a special environment could be verified.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.2
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• pp.147-155
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• 2024

Gallium-68-prostate-specific membrane antigen-11 (⁶⁸Ga-PSMA-11) is a positron emission tomography radiopharmaceutical that labels a Glu-urea-Lys-based ligand with ⁶⁸Ga, binding specifically to the PSMA. It is used widely for imaging recurrent prostate cancer and metastases. On the other hand, the preparation and quality control testing of ⁶⁸Ga-PSMA-11 in medical institutions takes over 60 minutes, limiting the daily capacity of ⁶⁸Ge/⁶⁸Ga generators. While the generator provides 1,110 MBq (30 mCi) nominally, its activity decreases over time, and the labeling yield declines irregularly. Consequently, additional preparations are needed, increasing radiation exposure for medical technicians, prolonging patient wait times, and necessitating production schedule adjustments. This study aimed to reduce the ⁶⁸Ga-PSMA-11 preparation time and optimize the automated synthesis system. By shortening the reaction time between ⁶⁸Ga and the PSMA-11 precursor and adjusting the number of purification steps, a faster and more cost-effective method was tested while maintaining quality. The final synthesis time was reduced from 30 to 20 minutes, meeting the standards for the HEPES content, residual solvent EtOH content, and radiochemical purity. This optimized procedure minimizes radiation exposure for medical technicians, reduces patient wait times, and maintains consistent production schedules, making it suitable for clinical application.