• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.6
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• pp.470-477
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• 2015

This paper presents a new technique for generating an optimum synchronizable test sequence that can be applied in the distributed test architecture where both external synchronization and input/output operation costs are taken into consideration. The method defines a set of phases that constructs a tester-related digraph from a given finite state machine representation of a protocol specification such that a minimum cost tour of the digraph with intrinsically synchronizable transfer sequences can be used to generate an optimum synchronizable test sequence using synchronizable state identification sequences as the state recognition sequence for each state of the given finite state machine. This hybrid approach with a heuristic and optimization technique provides a simple and elegant solution to the synchronization problem that arises during the application of a predetermined test sequence in some protocol test architectures that utilize remote testers.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.6
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• pp.539-545
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• 2016

UPS system in the liquefied natural gas(LNG) receiving terminal is one of the fundamental equipment that need to sustain operation during earthquake. In this study, modal identification test of UPS system was performed based on IEEE Std. 693-2005 and natural frequencies and modal damping, mode shapes had been identified. In addition, tri-axial time history test was performed to check the behavior and stress of the equipment during earthquake. Eigenvalue analysis was performed and analysis model was modified by reflecting the results of the test. Static analysis by dead weight and response spectrum analysis were performed to compare the combined stresses with the stress results of test. Dynamic characteristics and combined stresses under seismic load condition of the improved analysis model were similar to the test results and in this regard the compatibility was proved.

• The Transactions of the Korea Information Processing Society
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• v.5 no.3
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• pp.862-872
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• 1998

In this paper, we developed a delay test architecture and test procedure for clocked sequential circuit. In addition, we analyze the problems of conventional and previous method on delay test for clocked sequential circuit in IEEE 1149.1. This paper discusses several problems of Delay test on IEEE 1149.1 for clocked sequential circuit. Previous method has some problems of improper capture timing, of same pattern insertion, of increase of test time. We suggest a method called ARCH-S, is based on a clock counting technique to generate continuous clocks for clocked input of CUT. A 4-bit counter is selected for the circuit under test. The simulation results ascertain the aecurate operation and effectiveness of the proposed architecture.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.933-934
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• 2007

We fabricated and tested a resistive type superconducting fault current limiter (SFCL) based on BSCCO-2212 bulk coils. Each bulk coils of the SFCL was designed to have the rated voltage of 220 $V_{rms}$ and the critical current($I_C$) of 320$\sim$340 A at 77K. Ten components in series, make the SFCL having the rated voltage of 2.2 $kV_{rms}$ for equal quench test. The fault test was conducted at an input voltage of 2.2 $kV_{rms}$ and fault current of 25 $kA_{rms}$. In addition, we examined the endurance characteristics for all bulk coils through repeat fault test. Test results shows that the SFCL successfully limited the fault current of 25$kA_{rms}$ to below $7{\sim}8kA_{p}$ within minimum 1.1msec after fault occurred. All bulk coils quenched together upon faults and shared the rated voltage evenly. The endurance test results show an equivalent among repeat fault test. During the quench process, average temperature of all bulk coils did not exceed 250 K, and the SFCL was totally safe during the whole operation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.147-154
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• 2021

In this paper, the configuration and design of the test equipment are presented to examine the impact of rapid temperature change in cooling-air that may occur during the operation of the fixed wing aircraft Environmental Control System (ECS) on avionic electronic equipment. At the start of the ECS, the temperature of the air supplied by the aircraft ECS may be increased to 5.0℃ per second. In order to ensure operating of the avionic electronic equipment that is mounted on the aircraft and receives cooling-air from the ECS, testing equipment that can implement the cooling-air characteristic test environment is required. During design of test equipment was verified cooling-air rapid rate of temperature change by performing a thermal/flow analysis, performance of the test equipment implemented was verified by applying an avionic electronic equipment.

• Journal of Ocean Engineering and Technology
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• v.35 no.6
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• pp.446-456
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• 2021

To build an environment facility of a large-scale ocean basin, various detailed reviews are required, but it is difficult to find data that introduces the related research or construction processes on the environment facility. The current generator facility for offshore structure safety evaluation tests should be implemented by rotating the water of the basin. However, when the water in the large basin rotates, relatively large flow irregularities may occur and the uniformity may not be adequate. In this paper, design and review were conducted to satisfy the performance goals of the DOEB through computational numerical analysis on the shape of the waterway and the flow straightening devices to form the current in the large tank. Based on this, the head loss, which decreases the flow rate when the large tank water rotates through the water channel, was estimated and used as the pump capacity (impeller) design data. The impeller of the DOEB current generator was designed through computational numerical analysis (CFD) based on the lift surface theory from the axial-type impeller shape for satisfying the head loss of the waterway and maximum current velocity. In order to confirm the performance of the designed impeller system, the flow rate and flow velocity performance were checked through factory test operation. And, after installing DOEB, the current flow rate and velocity performance were reviewed compare with the original design target values. Finally, by measuring the current velocity of the test area in DOEB formed through the current generator, the spatial current distribution characteristics in the test area were analyzed. Through the analysis of the current distribution characteristics of the DOEB test area, it was confirmed that the realization of the maximum current velocity and the average flow velocity distribution, the main performance goals in the waterway design process, were satisfied.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.71-77
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• 2023

The issue of North Korea's denuclearization is an global issue that transcends the North and South. It is necessary to prepare for the denuclearization process in preparation for the situation in which North Korea reveals its intention to denuclearize. In the process of North Korea's denuclearization, it is required to guarantee the normal operation of the denuclearization verification equipment. If a performance test criteria that takes into account the North Korean environment is established, it is highly likely that it will be used in the future denuclearization process. For this purpose, basic materials related to performance test standards were established through analysis of test standards such as international standards. After that, we established a performance test criteria. This includes high temperature, low temperature, humidity, vibration and shock tests. Through follow-up studies, validity of test criteria will be established through actual device testing.

• Journal of the Korean Geotechnical Society
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• v.23 no.4
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• pp.133-147
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• 2007

Downhole seismic method is very economic and easy of operation because it uses only one borehole and simple surface source to obtain the shear wave velocity ($V_s$) profile of a site. Even though it is widely used by the site investigation companies, universities and institutes, however, the $V_s$ profile determined by downhole seismic method has often low reliability due to employment of wrong combinations of field losing equipment and interpretation method and deficiency of experience. Round robin test was performed and testing equipment and procedure were compared. Adequate downhole seismic testing equipment was constructed based on the comparison and verification study of the round robin test. The data acquisition and software interpretation were also developed for automation and quick test in field. Finally, the effectiveness and applicability were verified through the field test by using the constructed testing system.

• Journal of Biosystems Engineering
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• v.33 no.6
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• pp.379-383
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• 2008

A CRDI diesel engine used to commercial vehicle was fueled with diesel fuel and 20% biodiesel blended fuel (BDF 20%) and tested at the Seoul-10 mode for 150 hours. Engine dynamometer testing was completed at regularly scheduled intervals to monitor the engine performance and exhaust emissions. To check the engine parts (valve, injector), the engine was inspected after 150 hours running test. It was concluded that there was no unusual deterioration of the engine, or the changes in engine power (below 1.9%), smoke (below 4.1%), NOx (below 3.7%) and durability characteristics in spite of operation of 150 hours run with BDF 20%. The difference of kinetic viscosity for engine oil (before and after durability testing) was below 0.19% at $100^{\circ}C$.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2787-2794
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• 2011

A mesh node, a component of a mesh network, is connected with the network by dynamic routing using routing protocol and collects the information of adjacent or connected mesh nodes for its self-management and settings. Also, it relays packets between the mesh nodes and provides AP(Access Point) with its corresponding functions based on IEEE 802.11 a/b/g for clients' access to the network. In this paper, the study focused on the design and performance tests of Wireless Mesh Network(WMN) which is applied to the wireless communication network for the CBTC(Communications Based Train Control) system. The WMN was established on a K-AGT test-line (Kyeongsan city, Gyeongsangbuk-do), and to verify the applicability, its operation and performances are checked by measuring the data throughput, delay latency, quality measurements such as transmission loss, radio interference and path recovery and setup between the on-board and wayside.