• Journal of the Society of Disaster Information
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• v.9 no.1
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• pp.113-122
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• 2013

As the patronage of railroad increased, the government tried to introduce several the railroad safety program. The introduction of security inspection system in railroad is also considered with this background. In this paper, we examined the foreign cases in U.S., Spain, and China. Also, we surveyed the railroad users' opinion with the security inspection system and analyzed the results of survey for the sufficient preparation for it. Consequently, we suggested the introduction of high-speed rail station by way of showing an example.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.13-22
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• 2019

In order to evaluate the earthquake damage level of small and medium - sized bridges without earthquake monitoring system, we proposed an algorithm for estimating the seismic force at the target bridge location using the ground acceleration data from the earthquake observatories near the structure. In general, response spectrum analysis, which is the most widely used dynamic analysis method to design and evaluate the structural system numerically is required a response spectrum to determine the dynamic loading. In this study, selection methods of the three closest observatories from the target structure and estimation method of ground response spectrum at arbitrary locations are developed. The proposed method can consider the distance and phase between the target bridge and the seismic station and from the relationship between the acceleration amplitudes and the location of the selected seismic station, the earthquake loading of the target bridge can be determined. The proposed algorithm is estimated to be more conservative than the response spectrum evaluated by actual earthquake data.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.745-758
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• 2022

As the unlimited natural source of a country, radio waves are widely being used in the daily life toward knowledge based information society. Therefore it is necessary to provide a long term policy of radio waves management policies based on market situation to cope with rapidly changing wireless technology and effective use of radio resources. Literary survey and analysis were accomplished for the rules and regulations in the radio station approval system and post-approval policies for mobile communication service. In conclusion, this study propose an blanket radio approval policy as well as self declaration of conformity(SDoC) of radio waves technical regulation and advanced radio inspection procedure. This study has significance in providing reference for introducing deregulation policy in the radio communication imdustry.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.5
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• pp.653-658
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• 2011

In general, the purpose of packaging fasteners is a series of management activities to maintain the condition at the time of production until they get delivered to the end user. An automatic packing system for fasteners is consisted of bucket conveyor, slide feeder, vision inspection system, box-magazine conveyor system and automatic packing machine. Also, the automatic packing machine is consisted of six modules including charging device, clamping/opening device, sealing/cutting device, feeding/air-shower device, supplying/adjusting device and device frame, etc. In this paper, we proposed an automatic packing mechanism of the one station concept for packing work of fastener objects where the continuous batch work is performed in a finite space. The proposed one-station packing mechanism has been optimized through mechanical, dynamical, structural and fluid analyses. And it had been manufactured as the prototype of automatic packing machine. The field test for validation of performance was performed directly at the production line of bolt and screw. In the field test, this packing machine showed an efficiency of about 4.5 times the manual operation. It also showed 30% reduction in the consumption of packing materials compared to the manual operation. This automatic packing machine for fastener objects will be commercialized soon.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.2
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• pp.24-33
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• 2017

Domestic urban railway underground station structures, which were built in the 1970s ad 1980s, had been constructed as Cut-and-Cover construction system without seismic design. Because the trends of earthquake occurrence is constantly increasing all over the world as well as the Korean Peninsula, massive human casualties and severe properties and structures damage might be occurred in an non-retrofitted underground station during an earthquake above a certain scale. Therefore, to evaluate the retrofit effect and soil-structure interaction of seismic retrofitted underground station, a centrifugal shaking table test with enhanced stiffness on its structural main member are carried out on 1/60 scaled model using the Kobe and Northridge earthquakes. The seismic retrofitted members, which are columns, side walls, and slabs, are evaluated to comparing with existing non-retrofitted centrifuge test results Also, to simulate the scaled ground using variation of shear velocity according to site conditions such as ground depth and density, resonant column test is performed. From the test results, the relative displacement behavior between ground and structures shows comparatively similar in ground, but is increased on ground surface. The seismic retrofit effects were measured using relative displacements and moment behavior of column and side walls rather than slabs. Additionally, earthquake wave can be used to main design factor due to large structural deformation on Kobe earthquake wave than Norhridge earthquake wave.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.10
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• pp.1016-1019
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• 2011

In this paper, we predict a maximum electric field strength of WCDMA base station using a pilot channel in a code domain. In order to verify the feasibility of our method, we compare our predicted value on a self-designed test base station with a general electric field strength measurement value at a full-traffic load condition and with a calculated value by a ray-tracing technique. Predicted results show above 90 % agreement with the general measurement and calculation values. We also show that our prediction method can be applied to electric field measurement on a real operating base station. Therefore, it is concluded that our prediction method be an effective method to measure a maximum electric field strength in a base station inspection test.

• Journal of the Korea Society of Computer and Information
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• v.23 no.8
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• pp.1-7
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• 2018

Previous test equipment was bulky, took a long time to check, and was somewhat less economical. Since most of the checks were about analog signals, we preferred to check them using reference equipments. In this paper, a digital circuit design based on AITS is used to implement signals that can not utilize commercial measurement resources, and also designed and manufactured equipment that can inspect SRU. These test equipments were tested and evaluated by development, operation, and field evaluation, and they were installed to the Korean Field Force. This contributed to the improvement of operability by shortening the inspection time from 83.2 minutes to 7.8 minutes on average In addition, it did not utilize the reference equipment, so it could play a big role in lowering the mass production cost.

• IE interfaces
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• v.5 no.1
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• pp.15-23
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• 1992

In a transfer line with mass production capability, calibration systems are included in the process as a separate dedicated station. However, this method is not appropriate in an unattended FMC with flexibility. As the FMC produces vesatile parts with small batch sizes, more flexible calibration systems are required. In this paper, a calibration/inspection system suitable for an unattended turning cell is introduced. The system has functions of dimensional calibration of parts by touch probes, tool wear compensation, and quality monitoring of parts. Furthermore, characteristics of errors in the system are identified and corresponding compensation methodology is suggested. An operation software is developed for efficient use of the system.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.4
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• pp.41-47
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• 2012

Railroad rolling stock has long service life and a lot of maintenance cost running on rail by wear and vibration. And it is very important to get optimization of maintenance. This paper want to analyze rolling stock maintenance situation of KORAIL and find out its improvement methods. Especially, the purpose of this paper is to adopt the most effective maintenance period and methods to daily inspection which needs many maintenance manpower in rolling stock. Rolling stock has self-diagnosis function using computer system and the quality of rolling stock has much improved these days but current daily inspection repeat for short period routinely and it is very ineffective. Therefore, the paper adopt improved daily inspection period reflecting the characteristics of rolling stock, and want to secure reliability of rolling stock and minimize maintenance cost.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.433-438
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• 2010

Reactor vessel internals comprehensive vibration assessment program(RVI CVAP) is one of the necessary tests to ensure the safety of nuclear power plants. RVI CVAP of U.S. Nuclear Regulatory Commission Regulatory Guide 1.20(U.S. NRC R.G. 1.20) consists of the analysis, measurement, and inspection. One of the core technologies of the measurement program for RVI CVAP is to select suitable sensors. We analyzed RVI design data of Palo Verde nuclear generating station(U.S.) and Yonggwang nuclear generating station(Korea) and investigated measuring sensors used in both of them; moreover, we investigated sensors used for measurement of RVI CVAP for the last 20 years throughout the world. Based on these results, we selected the most suitable sensors for RVI CVAP in Advanced Power Reactor 1400(APR1400).