• Journal of Korean Society of Steel Construction
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• v.20 no.3
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• pp.445-454
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• 2008

Based on previous research on steel moment connections, experimental and analytical results showed that the deformation capacity was poor in specimens using RHS columns and with conventional weld access holes and strain concentration at the end of beam is influenced by the efficiency in transmitting the moment in the web of beam through the beam-to-column joint. This paper is focused on the retrofitting of pre-Kobe steel moment frame connections using a stiffened RBS and a welded horizontal stiffener. These retrofitting methods were considered only in beam bottom flange. A parametric study was performed using nonlinear finite element analysis to elucidate and improve the retrofit methods of connections.

• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.260-268
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• 2020

Currently, it is usually a 3D scanner processing method as a laser method. However, the laser method has a disadvantage of slow scanning speed and poor precision. Although optical scanners are used as a method to compensate for these shortcomings, optical scanners are closely related to the distance and precision of the object, and have the disadvantage of being expensive. In this paper, 3D scanner using variable focus lens-based structured light module with improved measurement precision was designed to be high performance, low price, and usable in industrial fields. To this end, designed a telecentric optical system based on a variable focus lens and connected to the telecentric mechanism of the step motor and lens to adjust the focus of the variable lens. Designed a connection structure with optimized scalability of hardware circuits that configures a stepper motor to form a system with a built-in processor. In addition, by applying an algorithm that can simultaneously acquire high-resolution texture image and depth information and apply image synthesis technology and GPU-based high-speed structured light processing technology, it is also stable for changes to external light. We will designed and implemented for further improving high measurement precision.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12B
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• pp.800-808
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• 2007

With the development of wireless data communication technology, all IP-based network will become compositions of wired and wireless networks. TCP is a connection-oriented, reliable transport protocol and has been used as de facto standard in most wired networks. Because TCP's congestion control algorithm could not distinguish congestion from BER, link failure and frequent route changes, TCP shows a poor performance over mobile ad-hoc networks. In this paper, the theoretical feature of TCP was studied and the performance of TCP over mobile ad-hoc networks was analyzed with ns2.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.3
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• pp.145-152
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• 2003

Electrical gate and drain characteristics of double heterostructure InAlAs/InGaAs pseudomorphic HEMTs have been investigated under sub-bandgap photonic excitation ($hv). Drain $(V_{DS})-,{\;}gate($V_{DS})-$, and optical power($P_{opt}$)-dependent variation of the abnormal gate leakage current and associated physical mechanisms in the PHEMTs have been characterized. Peak gate voltage ($V_{GS,P}$) and the onset voltage for the impact ionization ($V_{GS.II}$) have been extracted and empirical model for their dependence on the $V_{DS}$ and $P_{opt} have been proposed. Anomalous gate and drain current, both under dark and under sub-bandgap photonic excitation, have been modeled as a parallel connection of high performance PHEMT with a poor satellite FET as a parasitic channel. Sub-bandgap photonic characterization, as a function of the optical power with $h\nu=0.799eV$, has been comparatively combined with those under dark condition for characterizing the bell-shaped negative humps in the gate current and subthreshold drain leakage under a large drain bias.

• Journal of the Korean Society of Safety
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• v.29 no.2
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• pp.1-6
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• 2014

In this paper, safety certification products and safety condition of small transformer is analyzed in industries field and educational facilities. In transformer of 50places, absolute majority is step down transformer to measure of instrument. Most transformers were below 5kVA and 1~3kVA capacity was the mainstream. In industries field, 5 transformers were found without safety certification according to the Electrical Appliances Safety Control Act as cheap product prefer and lack of safety consciousness. Mark & number, voltage, date of manufacture of safety certification must show item of certification. However date of manufacture showed in product of 18%, 9places. As result of thermal imaging camera, running temperature of transformer was showed in below of target temperature. However as a narrow space of transformer and wall, power cable was touched on a ventilating flue in transformer. It was simple carelessness case that surface fouling and temperature ageing of transformer accelerate. Power poor connection, neglect of transformer in production equipment, fall damage by setup incongruity and ground omission were found in case of illogicality item of transformer.

• Korean Journal of Agricultural Science
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• v.21 no.1
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• pp.67-80
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• 1994

Farm land is considered the most important production factor in farm production. Land is not only one of the most scarce resource but also the size of land holding is the key factor in determining the size of farm income in Korea. To increase farm productivity by accepting bio-chemical and mechnical technology, the qualitative improvement of farm land through land consolidation and on-farm development have been carried out by the Korean government. Land consolidation with water resource development makes possible the high-tech-capital intensive farming, internal expansion of farm land and hightening the rate of land intensity in connection with UR problems. This paper contained the present status of farm land base development, allocation of investment by types of farm land development and the econome-trical analysis on the effects of the investment on rice productivity during the past 27 years since 1965. The rate of irrigated paddy area had been increased from 42% in 1965 to 74% in 1991. Land consolidated area out of the total paddy area had been achieved 44.9% and the improved rate of poor drained paddy area was shown 43.5% in 1991. To carry out the above farm land base development projects, the government had procured financial budgets consisting of the G't subsidy, long term loan, foreign loan, the provincial G't subsidy, WFP counter fund and farmer's burden.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.577-585
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• 2010

The Military Tactical Communication technology for effective network-centric warfare is developing. Targeting broadband wireless transmission, core technology for connection, and Transmission technology that secure survivability under High-speed Movement environment. On the one hand, Tactical data communication system that reflects military characteristic is developing on the base of Legacy communication equipment which is used in the field. Because almost every military units in the field have used voice to communicate which lower efficiency of operation, they have made effort to Substitute voice communication which delays military Operation Tempo to digital communication. The Communications environment of troops in Forward edge of battle field area is very poor. Especially in terms of limited frequency allocation and bandwidth. Therefore, improving the efficiency of frequency is essential for Military Tactical Communication. This paper is about The Data Compression Method for increase of Efficiency in Tactical Data Communication over Legacy Radios which are UHF, VHF, HF Radio. I proposed and proved the most efficient Data Compression Method that reflects military characteristic, after analyzing the experimentation, which simulate CAS(Close Air Support mission) data transmission between Pilot and TACP.

• Journal of Welding and Joining
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• v.25 no.6
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• pp.44-52
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• 2007

A welding process of a lifting lug for lifting heavy objects is one of the important welding processes directly related to the safety in shipbuilding. Welding a lifting lug is done in the manually and takes about forty minutes. Working environment for the lifting lug welding is very poor due to an radiant heat and a harmful fume. The purpose of this study is to develop methods of multi-pass welding using the lifting lug welding robot system. This study shows robot welding methods to achieve proper corner, straight and connection welding and an effectiveness of application.

• Child Health Nursing Research
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• v.25 no.3
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• pp.303-311
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• 2019

Purpose: This study aimed to examine engagement and satisfaction with a mobile web-based education program (HiChart) among pregnant women. Methods: A cross-sectional descriptive study was conducted of 97 pregnant women hospitalized for obstetric care. Data were collected from October 1 to November 30, 2016, and were analyzed with descriptive statistics. Results: Among participants, 16.5% engaged fully with HiChart, while 43.3% engaged partially. The overall satisfaction with HiChart was high. Some main reasons for not engaging with the education were participants' unawareness of the text messages, lack of time, and poor internet connection. The participants suggested that more educational content needed to be covered, such as coping with infant emergencies and information about the neonatal intensive care unit. Conclusion: To increase pregnant women's engagement with mobile web-based education, efforts are needed to strengthen the system of sending text messages as part of mobile web-based education to all patients, to inform pregnant women that an educational web link was sent, and to encourage them to engage with mobile web-based education. Furthermore, it is essential to improve the HiChart service by providing educational content corresponding to users' needs.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.255-262
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• 2021

The paper examines the influence of ownership type on environmental performance of Chinese listed enterprises. China's environmental problems are attributed to the collusion between enterprises and economy-oriented local governments, which has allowed many companies to skirt environmental regulations. Especially, local state-owned enterprises (SOEs) tend to have worse environmental performance than private firms, under the wing of local governments, with whom they have a closer political connection. According to the report of the Environmental Protection Agency, currently the unacceptably poor environmental performance of local SOEs has severely hampered the realization of green economy in China. After examining the dataset of 15,996 firm-year observations from 2,688 listed firms, this paper found that, in the presence of central government supervision and personnel intervention, listed local SOEs will be forced to improve their environmental performance in accordance with standards set by the central government, which leads to better environmental performance than that of listed private firms (private firms). The result of two-stage regression also supports the conclusion. This shows increased supervision and personnel intervention from the central government can significantly improve the environmental performance of local SOEs. The research in this paper expects to make a contribution to attaining the goal of green economy in China.