• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.12
• /
• pp.2800-2805
• /
• 2013

In preperation for the compulsory installation of VHF(Very High Frequency) wireless equipment and fishing vessel automatic identification system according to the revision of "The Ships Safety Act" and "Fishing Vessel act", Fishery Information & Communication Department of National Federation of Fisheries Cooperatives is building VHF communication network and automatic identification system for fishing vessel monitoring. This study suggests the protocol analysis for the calling of location requirement using DSC(Digital Selective Calling) function and show best way for fishing vessel automatic identification system. Also, it suggest way to realize fishing vessel monitoring system.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.21 no.9
• /
• pp.50-55
• /
• 2022

Acceleration performance, maximum velocity, urban driving energy consumption, and high-way driving energy consumption are important characteristics of electric vehicle driving. This study analyzes the effect of a gear ratio on these characteristics for a front wheel drive electric vehicle. The normalized sensitivity metric is used to compare the sensitivity of these scaled characteristics to the changes in the gear ratio. The sensitivity analysis results show that the normalized values are 0.95 for maximum velocity, 0.91 for acceleration performance, 0.51 for urban driving energy consumption, and 0.24 for high-way driving energy consumption. Therefore, the maximum velocity was affected the most by the changes in the gear ratio. These results can be used to determine the gear ratio of a front wheel drive electric vehicle to optimize the driving characteristics simultaneously.

• Nuclear Engineering and Technology
• /
• v.55 no.3
• /
• pp.927-938
• /
• 2023

The blanket plays an important role in fusion reactor and stands extremely high thermal and electromagnetic loads during operation situation and plasma disruption event, brings the need for precise thermal and electromagnetic analysis. Since the thermal field and EM field interact with each other nonlinearly, we develop a method of electromagnetic-thermal two-way coupling by using finite element software COMSOL. The coupling analyses of blanket under steady state and MD event are implemented and the results are analyzed. For steady state, the influences of coupling effects are relatively small but still recommended to be considered for a high precision analysis. The influence of thermal field on EM field can't be ignored under MD events. The variation of force density could cause a significant change in stress in certain parts of blanket. The influence of Joule heat during MD event is negligible, yet the potential temperature rise caused by induced current after MD event still needs to be researched.

• Progress in Superconductivity and Cryogenics
• /
• v.20 no.1
• /
• pp.11-14
• /
• 2018

High Temperature Superconducting (HTS) power cables are capable of transmitting bulk power without any loss compared to conventional copper cables. The major challenge in the design of such HTS cables is the high stresses (electro-thermal/electro-mechanical) developed at high voltages, high currents and cryogenic temperatures. The safe and reliable operation of HTS cables involves lots of instrumentation for monitoring, measurement, control and safe operation. In principle, a four probe method for resistance (RTD PT-100) is used for temperature measurements at various locations of HTS cable. The number of connecting leads required for this is four times that of the number of sensors. The present paper discusses a novel way of connecting 128 RTD sensors with the help of only 14 leads using a cold electronics based multiplexer board. LabVIEW 11.0 software was used for interfacing and displaying the readings of all the sensors on computer screen.

• Culinary science and hospitality research
• /
• v.20 no.5
• /
• pp.136-147
• /
• 2014

This study aims to identify the importance and satisfaction levels of home meals of high school students. A developed survey was conducted on July 10 through July 13, 2012. Of 12 high schools located in three different areas in South Korea, three high schools were singled out. For the analyses of the study, the following statistical methods were employed: frequency, cross-tabulation, independent sample t-test, one-way ANOVA, and Duncan as a post-hoc test. As a result, food experiences and education through home meals during childhood promote close ties with other family members and help them develop the food taste and preference that can naturally raise the meal satisfaction level by developing proper eating habit. More implications and discussion are suggested.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.15 no.6
• /
• pp.27-34
• /
• 2001

There are several electricity applied sterilizers such as using high frequency, ozone, high voltage, and so on. Those sterilizers feature "because of no chemical process and no secondly environmental pollution". At the power conversion part, ZVS and ZCS methods have been used that it results in reduced switching loss, miniaturized size, and lightened weight. Besides, the current in the propose device is smaller than that of existing method. Thus, it is expected that the cost of sterilization process, when quality of the device is measured by power consumption, will be reduce. Therefore, the purpose of this research is to solve the sterilization problems of existing powder with high voltage and field to and more economical and effective way, and to suggest mere improved sterilizer.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.22 no.1
• /
• pp.156-161
• /
• 2013

Recently, there has been a trend in the manufacturing process to focus on the durability of cable lug joint, especially in welding process due to the poor cable lug joint causes many troubles on products and workers during manufacturing process. Therefore development of high quality cable lug joint is important for successful manufacturing process and safety of worker. The Magnetic Pulse Forming(MPF) is one of efficient way to developed a high quality cable lug joint. In MPF, a high strain rate forming process, utilizes a high velocity oblique collision on the workpiece to be formed in required shape. The objective of this paper is to develop of high quality cable lug joint using electromagnetic force. To successfully accomplish this goal, section and electrical contact temperature of developed cable lug joint has been compared with various cable lug joint. Electrical contact temperature of developed cable lug joint by electromagnetic force is lower than manufactured cable lug joint by pressurer and hydraulic pressurer.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.265-268
• /
• 1999

In this study, we manufactured the ultra-high strength concrete using mineral admixture which is easily workable. From the test results of compressive strength, It is concluded that the proper replacement ratio of silica fume should not exceed to 10% and the replacement of slag is more effective that the replacement of fly ash to gain very high compressive strength. Thermal stress analysis is conducted to find the way of controlling the thermal crack of ultra-high strength concrete. As results of thermal stress analysis, it was found that reducing placing temperature of concrete(pre-cooling) is effective to reduce thermal crack and placing concrete in high air temperature is more effective than placing concrete in low air temperature.

• Journal of information and communication convergence engineering
• /
• v.15 no.4
• /
• pp.212-216
• /
• 2017

In this paper, we introduce novel techniques to improve the high performance of AE functions on modern high-end IoT platforms (ARM-NEON), which support SIMD and cryptography instruction sets. For the Sophie Germain Counter Mode of operation (SGCM), counter modes of encryption and prime field multiplication are required. We chose the Montgomery multiplication for modular multiplication. We perform Montgomery multiplication in a parallel way by exploiting both the ARM and NEON instruction sets. Specifically, the NEON instruction performed 128-bit integer multiplication and the ARM instruction performed Montgomery reduction, simultaneously. This approach hides the latency for ARM in the NEON instruction set. For a high-speed counter mode of encryptions for both AE functions, we introduced two-level computations. When the tasks were large volume, we switched to the NEON instruction to execute the encryption operations. Otherwise, we performed the encryptions on the ARM module.

• Journal of Welding and Joining
• /
• v.20 no.4
• /
• pp.551-556
• /
• 2002

Solid particle erosion wear characteristics of high Cr white iron hardfacing were investigated using the erosion wear test method according with the ASTM G76-95. Wear experiments, where the blast angle, blast distance and blast pressure were selected as test variables, were planned and analyzed by response surface method (RSM to evaluate the wear loss statistically and quantitatively. The measured wear losses well coincided with the calculated ones by the experimental equation. The wear loss of high Cr cast iron hardfacing was increased with blasting pressure, but affected in a complicated way by the blasting angle and distance. Erosion wear of high Cr cast iron hardfacing could be well predicted by RSM analysis of wear variables.