• IE interfaces
• /
• v.11 no.1
• /
• pp.1-14
• /
• 1998

Various problems on logistics systems have been dealt with recently as research issues since they were regarded critical for taking up a better position in the increasingly competitive global market. In particular, the freight transportation is considered as a key factor which affects the economic competitiveness of a whole nation as well as the production cost of individual companies. The objective of this study is to identify main issues and review recent foreign and domestic studies related to the freight transportation. The studies are classified into two categories according to the hierarchical level in the decision making process: infra structure design and transportation strategies, service design and operation. Main issues are introduced with a brief review on the related literature and methodologies applied.

• Korean Journal of Computational Design and Engineering
• /
• v.4 no.4
• /
• pp.295-311
• /
• 1999

An increasing attention is paid to STEP-NC, the next generation CNC controller interfacing STEP-compatible data. In this paper, we first propose an Architecture for the STEP-NC (called FBCC: Feature Baled CNC Controller) accepting feature code compatible with STEP-data, and executing NC motion feature by feature while monitoring the execution status. The main thrust of the paper has been to develop an automatic on-line tool path generation and modification scheme for milling operation. The tool path it generated iota each feature by decomposing into a finite number of primitive features. The key function in the new scheme is haw to accommodate unexpected execution results. In our scheme, the too1 path plinker is designed to have a tracing capability iota the tool path execution so that a new path can be generated from the point where the operation is stopped. An illustrative example is included to show the capability of the developed algorithm.

• Korean Journal of Computational Design and Engineering
• /
• v.17 no.3
• /
• pp.198-207
• /
• 2012

This paper presents an overview of automated robotic system for skull drilling, which is performed to access for some neurosurgical interventions, such as brain tumor resection. Currently surgeons use automatic-releasing cranial perforators. The drilling procedure must be performed very carefully to avoid penetration of brain nerve structures; however failure cases are reported. The presented prototype system utilizes both preoperative and intraoperative information. Preoperative CT image is used for robot path planning. A NeuroMate robot with a six-DOF force sensor at the end effector is used for intraoperative operation. Intraoperative cutting force from the force sensor is the key information to revise an initial registration and preoperative path plans. Some possibilities are verified by path simulation but cadaver experiments are required for validation of this prototype.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.316-321
• /
• 2001

A previous feasibility study for the Korean lead plant, PLiM Phase I, showed a strong possibility of continued operation beyond the original licensed period. In 1998, PLiM Phase II study was initiated aimed at performing additional detailed evaluations on a wider range of components. The objective of this paper is to present the Korean PLiM efforts for Class 1 piping which is identified as one of the critical components with regard to long-term operation. The key findings such as typical design features, degradation mechanisms, technical issues, draft results from the lifetime evaluation for Class 1 piping of the lead plant are briefly described.

• Proceedings of the KIEE Conference
• /
• 2008.10c
• /
• pp.126-128
• /
• 2008

This paper presents an architecture for driving multiple paralleled cold cathode fluorescent lamps (CCFLs) for back lighting applications. Multi CCFL operation and increase of brightness, the key to the architecture is a proposed capacitive coupling approach for lamp ignition. This system is consist of a flyback converter, a single inverter to drive multiple lamps and conductive floating reflector. The topology is capable of driving a number of parallel lamps with independent accurate lamp, The capacitive coupling the leakage inductance and stray capacitance creation which it used, current regulation and improving cost effectiveness with significant reduction in size and weight, compared to typical high frequency ac ballast. Experimental demonstration results for ten of parallel CCFLs with simultaneous ignition.

• Journal of Information Processing Systems
• /
• v.9 no.3
• /
• pp.499-510
• /
• 2013

Hardware-Software co-simulation of a multiple image encryption technique shall be described in this paper. Our proposed multiple image encryption technique is based on the Latin Square Image Cipher (LSIC). First, a carrier image that is based on the Latin Square is generated by using 256-bits of length key. The XOR operation is applied between an input image and the Latin Square Image to generate an encrypted image. Then, the XOR operation is applied between the encrypted image and the second input image to encrypt the second image. This process is continues until the nth input image is encrypted. We achieved hardware co-simulation of the proposed multiple image encryption technique by using the Xilinx System Generator (XSG). This encryption technique is modeled using Simulink and XSG Block set and synthesized onto Virtex 2 pro FPGA device. We validated our proposed technique by using the hardware software co-simulation method.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.55 no.12
• /
• pp.661-666
• /
• 2006

Interlocking signalling system plays key role as core system to manage railway operation. The core role of railway operation is to control routing, displaying signal and regulation for train. Interlocking system relate tightly to railway accident because collision and derailment is sometime taken place wrong route setting and signal displaying. Safety activity for interlocking system is inevitable to avoid the accident over its life cycle. The safety activity includes hazard identification and analysis, safety requirement allocation, safety plan, safety activity and ao on. The safety activity need a broad wide range work. In this paper, we concentrate on hazard identification for generic interlocking system and programmable electronic interlocking system and compare between two results. The hazards will be used for safety activity.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.12
• /
• pp.3149-3165
• /
• 2013

Content based image retrieval is increasingly gaining popularity among image repository systems as images are a big source of digital communication and information sharing. Identification of image content is done through feature extraction which is the key operation for a successful content based image retrieval system. In this paper content based image retrieval system has been developed by adopting a strategy of combining multiple features of shape, color and relevance feedback. Shape is served as a primary operation to identify images whereas color and relevance feedback have been used as supporting features to make the system more efficient and accurate. Shape features are estimated through second derivative, least square polynomial and shapes coding methods. Color is estimated through max-min mean of neighborhood intensities. A new technique has been introduced for relevance feedback without bothering the user.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.135-138
• /
• 2009

Quality evaluation of laser welded MCFC separator panels with large active area was performed. Lap joint was applied to produce stable air-tight seam weld by employing Nd:YAG laser. Results showed that surface contamination played a key role to form weld defects at the joint interface. However, there was no evidence that weld width at the lap joint changed after the stack operation time of 2,890h. Test results also revealed that the reinforcement values which were measured on the weld line after long time operation, were stable.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.28 no.1
• /
• pp.115-121
• /
• 2020

Recently avionics equipment and its integration are most important part for implementing high performance aircraft system. This trends are emphasized in the military or special purpose aircraft development program. Flight Test Bed Aircraft (hereafter FTB A/C) - by modified commercial aircraft - was key solution to verify function and performance of avionics system for complex aircraft development program for a while, but there are no experience to use it in domestic airspace of ROK. This paper would like to address what act and regulation is necessary to perform flight operation of FTB A/C with keeping a airworthiness and airspace control policy. and then willing to propose what do we do for improving aviation industry.