• Proceedings of the KSR Conference
• /
• 2002.05a
• /
• pp.492-497
• /
• 2002

This study presents the core contents and superiority of localized Point-Machine which Alstom transferred its technology to Samsung SDS for High Speed Rail, developed based on existing MJ8l Point-Machine that is used in France and other countries. The scope of study includes introducing performance improvement of Localized MJ8l and conducting comparative analysis between Localized MJ8l and french products as well as NS type Point-Machine that has been deployed in the existing rail link. Moreover, the general architecture, features and test run results of Localized MJ8l are described.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.5
• /
• pp.465-472
• /
• 2016

This study materialized an FPGA-based system to extract PCB patterns. The Printed Circuit Boards that are produced these days are becoming more detailed and complex. Therefore, the importance of a vision system to extract defects of detailed patterns is increasing. This study produced an FPGA-based system that has high speed handling for vision automation of the PCB production process. A vision library that is used to extract defect patterns was also materialized in IPs to optimize the system. The IPs materialized are Camera Link IP, pattern matching IP, VGA IP, edge extraction IP, and memory IP.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.65 no.2
• /
• pp.114-121
• /
• 2016

This paper is Instant space vector PWM(Pulse Width Modulation)power conversion devices in switching power semiconductors from my generation to losses and switching when the voltage surge and current surge of electronic noise(EMI: Electro Magnetic Interference / RFI: Radio Frequency Interference)to effectively minimize the power soft-switching power conversion circuit topologies of auxiliary resonant DC tank for the purpose of high performance realization of the electric power conversion system by the high-speed switching of a semiconductor device(AQRDCT simultaneously : an active auxiliary resonance using auxiliary Quasi-resonant DC tank)DC link snubber switch has adopted a three-phase voltage inverter. AQRDCL proposed in this paper can reduce the effective and current peak stress of the power semiconductors of the auxiliary resonant snubber circuit compared to the conventional active-resonant DC link snubber, it is not necessary to install the clamp switch of the auxiliary resonant DC link, DC the peak current and power loss of the bus line can be reduced.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.12B
• /
• pp.1695-1702
• /
• 2001

This paper describes a design of CMOS infrared (IR) wireless data link IC which can be used in IrDA(Infrared Data Association) application from 4 Mb/s to 100 Mb/s The implemented chip consists of variable gain transimpedance amplifier which has a gain range from 60 dB to 100 dB, AGC (automatic gain control) circuits, AOC(automatic offset control) loop, 4 PPM (pulse position modulation) modulator/demodulator and DLL(delay locked loops). This infrared optical link If was implemented using commercial 0.25 um 1-poly 5-metal CMOS process. The chip consumes 25 mW at 100 Mb/s with 2.5 V supply voltage excluding buffer amplifier. The die area of prototype IC is 1.5 mm $\times$ 1 mm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.10
• /
• pp.135-140
• /
• 2006

In this paper, we present hybrid ARQ techniques to improve the throughput performance in high speed packet transmission such as Internet or multimedia services. In order to evaluate the performance of the three different types of hybrid ARQ schemes, systemized link level simulations based on WWW traffic model are considered. In this paper, we also consider the simulated performance for an average link throughput and a normalized packet delay to compare the hybrid ARQ with link adaptation scheme in GPRS.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.10
• /
• pp.1402-1411
• /
• 2014

In this paper, the Maximum Power Point Tracking(MPPT) control of the small scale wind power generation system with a three-phase diode rectifier and the grid-connected inverter is studied. Without the need for the converter circuits to control speed of the generator, it is economical and the structure is simple. Compared with existing systems, it can be to reduce the power semiconductor switches and passive elements, and to implement the MPPT control with only DC-Link voltage control of the grid-connected inverter. In order to allow MPPT control without the characteristic information of the wind turbine, the P&O algorithm is applied, and these are verified by the simulation and experiment.

• Journal of information and communication convergence engineering
• /
• v.11 no.1
• /
• pp.1-6
• /
• 2013

Suppressing or mitigating signal distortion due to group velocity dispersion and optical Kerr effects is necessary in ultra-high speed and long-haul wavelength division multiplexing (WDM) transmission systems. Dispersion management (DM), optical phase conjugation (OPC), and the combination of these two are promising techniques to compensate for signal distortion. In this paper, to implement a flexible optical WDM network, a new optical link configuration with a randomly distributed single-mode fiber (SMF) length and fixed residual dispersion per span in the combination of DM and OPC is proposed and investigated. The simulation results show that the best net residual dispersion (NRD) in the proposed optical links is +10 ps/nm, which is independent of pre- and postcompensation. The effective launch power of the WDM channel is increased more in the optical links with NRD = +10 ps/nm controlled by only precompensation. Furthermore, the system performance difference between the proposed optical link configuration with the best NRD and the conventional optical link with uniform distribution of the SMF length had little significance. Consequently, it is confirmed that the proposed optical link configuration with the best NRD is effective and useful for implementing a reconfigurable long-haul WDM network.

• Journal of Forest and Environmental Science
• /
• v.39 no.4
• /
• pp.203-212
• /
• 2023

Directional felling is a felling method practised by the Forestry Department in Peninsular Malaysia as prescribed in Field Work Manual (1997) for Selective Management Systems (SMS) in forest harvesting. Determining the direction of tree felling in Peninsular Malaysia is conducted during the pre-felling inventory 1 to 2 years before the felling operation. This study aimed to predict and analyze the direction of tree felling using the vector-based path distance back link method in Geographic Information Systems (GIS) and compare it with the felling direction observed on the ground. The study area is at Balah Forest Reserve, Kelantan, Peninsular Malaysia. A Path Distance Back Link (spatial analyst) function in ArcGIS Pro 3.0 was used in predicting tree felling direction. Meanwhile, a binary classification was used to compare the felling direction estimated using GIS and the tree felling direction observed on the ground. Results revealed that 61.3% of 31 trees predicted using the vector-based projection method were similar to the felling direction observed on the ground. It is important to note that dynamic changes of natural constraints might occur in the middle of tree felling operation, such as weather problems, wind speed, and unpredicted tree falling direction.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.7 no.1
• /
• pp.39-49
• /
• 2019

Purpose - The major aim of this article is to advance understanding of the relationship between market orientation and speed-to-market. Specifically, this study examines the different impacts of component of market orientation on commitment to R&D and speed-to-market and explores whether market uncertainty plays a role of moderating in speed-to-market for market-oriented firms. Research design, data, and methodology - This study collected a survey data from Korean exporting firms. The Final sample size was 196. The measure of market orientation was conceptualized with second order constructs. All items were measured on five-point scale. To confirm hypotheses, this study conducted a hierarchical regression. Results - As sub-constructs of market orientation, customer orientation, competitor orientation and interfunctional coordination foster speed-to-market, and the relationship between only customer orientation and speed-to-market might be weakened when the extent of market uncertainty is high. Conclusions - This study confirmed the relationship between market orientation and speed-to-market, with three components of market orientation respectively, and whether market uncertainty plays a role of moderating which weaken the link between market orientation and speed-to-market. It could be useful to take a component approach to the market orientation construct, because the roles of different market orientation components might vary, contingent on uncertainty in the environment.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.5 s.122
• /
• pp.415-426
• /
• 2007

In a link motion punch press, numerous links are interconnected and each link executes a constrained motion at high speed. As a consequence, dynamic unbalance force and moment are transmitted to the main frame of the press, which results in unwanted vibration. This degrades productivity and precise stamping work of the press. This paper presents an effective method for reducing dynamic unbalance in a link motion punch press based upon kinematic and dynamic analyses. Firstly, the kinematic analysis is carried out in order to understand the fundamental characteristics of the link motion mechanism. Then design variable approach is presented in order to automate the model setup for the mechanism whenever design changes are necessary. To obtain the inertia properties of the links such as mass, mass moment of inertia, and the center of mass, 3-dimensional CAD software was utilized. Dynamic simulations were carried out for various combinations of design changes on some links having significant influences on kinematic and dynamic behavior of the mechanism.