• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1550-1557
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• 2007

New locomotives 8100 & series 8200, based on the BR152 of German railway are suitable for heavy-duty freight traffic as well as for passenger transport. This electric locomotive had applied by trial petition way and 57 car is operating in mainline and industrial line until now. As matter of fact, this has a purpose to help designing and manufacturing the new electric locomotive in these day when almost all the line is changing into the electric fire line. This thesis has a purpose to check whether the actual simulation value properly apply and meet the designing value, comparing the result of the simulation for the performance of developed locomotive with the result of the type test which can be proceed in actual locomotive in korea (evaluating both the design value and the performance of the real locomotive).

• Journal of applied mathematics & informatics
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• v.27 no.5_6
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• pp.1343-1359
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• 2009

In this paper, we implement a relatively new analytical technique by combining the traditional variational iteration method and the decomposition method which is called as the variational decomposition method (VDM) for solving the sixth-order boundary value problems. The proposed technique is in fact the modification of variatioanal iteration method by coupling it with the so-called Adomian's polynomials. The analytical results of the equations have been obtained in terms of convergent series with easily computable components. Comparisons are made to verify the reliability and accuracy of the proposed algorithm. Several examples are given to check the efficiency of the proposed algorithm. We have also considered an example where the VDM is not reliable.

• Journal of Biomedical Engineering Research
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• v.13 no.2
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• pp.141-146
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• 1992

The propagation, reflection and scattering characteristics of the near Infra-red lights were experimented in order to check the feasibility of non-restrained biotelemetry using indirect transmitted light. The results of the experiments show that 3 kinds of walls examined are not specular reflectors but almost perfect diffuse surfaces with slight directivity and that light in a local point is spread out and fills the room uniformly by repeating the reflection and scattering at walls, ceiling, floor. These results also explain the fact that the diffusely reflected light can be utilized as the carrier of biotelemetry even after several scattering and reflections.

• Journal of the Korea Safety Management & Science
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• v.5 no.2
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• pp.239-253
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• 2003

Lecture Evaluation system is an only way, so far, to evaluate the quality of lectures in our university and yet has several problems. This system does not have any effects on professors; however, it is rather used to threaten assistant professors and/or part-time/full-time lecturers. As a result, students are still dissatisfied with the unchanging lectures of professors. Generally speaking, We should consider new ideas to introduce a head teacher system or improve the lecture evaluation system to open doors wider for teachers, professors do their best to expand students' understanding by practicing the Lecture Evaluation System. In fact, it is hard to keep the objectiveness that the professors estimate the quality of professors. That is why this check list should be restricted only as a guideline among the system. After all, it is expected to bring better educational circumstances when the system functions properly to provide professors to research more.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.349-355
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• 2008

In this paper, a wireless remote monitoring system for leakage current of distribution board is developed. In the developed system, signals of the leakage current of distribution board are transmitted to a monitoring system using wireless communication. The developed system is consisted of a comparative module, control module, a wireless communication module, and hand held terminal. The developed system has any facilities which can check a leakage current with real time, send to the user this fact using a wireless remote interface method. And also developed system can take precaution for an accident by leakage current.

• Economic and Environmental Geology
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• v.27 no.1
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• pp.65-80
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• 1994

The Tertiary $Ch{\check{o}}ngja$ basin is located in the southeastern coastal area of the Korean Peninsula. It is a lozenge shaped fault-bounded basin with circa $5{\times}5km$ areal extent, isolated from other Tertiary basins by the Cretaceous Ulsan Formation in-between. The northwestern boundary of the basin is a domino/listric type normal fault trending $N30^{\circ}E$, whereas its southwestern boundary is a dextral strike-slip fault (trending $N20^{\circ}W$) with a lateral offset of more than 1 km. The basin is bounded by the East Sea on the eastern margin. Basin-fills consist of extrusive volcanic rock (Tangsa Andesites) of Early Miocene (16~22 Ma in radiometric age), unconsolidated fluviatile conglomerate (Kangdong Formation) and shallow brackish-water sandstone ($Sinhy{\check{o}}n$ Formation). The latter yields abundant Vicarya-Anadara molluscan fossils of early Middle Miocene age. The Tertiary strata become younger toward the northwestern boundary-fault of the basin, showing a zonal distribution pattern parallel to the fault: the younger sedimentary formations occupy a narrow zone of 2 km width along the northwestern boundary-fault, whereas the older Tangsa Andesites underlie them unconformably in the eastern and southeastern portions of the basin. The strata in the basin, including the Tangsa Andesites, are tilted (about $20^{\circ}$) toward the northwestern boundary-fault Sedimentary strata thicken toward the boundary-fault, forming a wedge shaped half-graben structure. A number of small-scale syndepositional normal growth faults and graben structures are observed in the sedimentary strata. These extensional structures have the same trend as the normal northwestern boundary-fault which we interpret as a pull-apart detachment fault. These characteristics imply persistent extension during the basin evolution, caused by a NW-SE directed tensional force. The $Ch{\check{o}}ngja$ basin is, thus, a kind of syndepositional tectonic basin evolved in a strike-slip (pull-apart) regime. The latter was caused by a dextral simple shear associated with the NNW-SSE opening of the East Sea. In view of the fact that the normal growth faults do not cut through the uppermost portion of the youngest $Sinhy{\check{o}}n$ Formation, it is inferred that the tensional force came to be inactive in the early Middle Miocene. This is coincident in timing with the termination of the East Sea opening (15 Ma).

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.2
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• pp.173-180
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• 2014

In the design of tunnel segment structure, axial and moment forces are considered as significant forces. Since axial force is much greater than moment force, the whole section of segment remains in compression. Therefore crack width can be reduced. But the axial force is not considered in criteria for serviceability check. This fact leads service condition more severe compared to ultimate condition and makes the required steel reinforcement increase to meet the serviceability criteria. In this study, the effect of axial force on serviceability of tunnel segment is evaluated, experimentally and analytically. Mock-up tests on segments with actual size were performed and investigated in terms of initial crack resistance. The evaluation proves that more comprehensive design could be achieved when the axial force is considered in the procedure for the serviceability check in design of tunnel segment.

• Korean Security Journal
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• no.14
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• pp.109-123
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• 2007

Traffic terror is one of the terror types subject on transportation means. However, unlike the aircraft or ship, there is no case of negotiating with passengers as hostage but to unconditionally attack that the human casualty would be much greater. In act, the terror on subway or bus would have much bigger damage than the terror on aircraft or ship. Because of such fact, there is a need for full preparation thereto, however, there is no preparation of advance preventive measure, particularly, when comparing to the cases involving aircraft. In addition, the passengers who use railway and others in the position of citizens do not have any defense mechanism against any terror activity to make the problem even more serious. Therefore, in order to prevent traffic terror, the first thing is to implement the identity confirmation of passengers, followed by the through search of cargos of the passengers, supplement the capability against the terror by the security team members, strengthen the responsive capability of citizens, thorough check on facilities, expansion of social security network and others. All terrors are within the reach of our neighborhood at the time when we neglect it, and the most secured and safe way to prevent the terror is to check and prepare at all times beginning from our familiar facilities or means.

• The Journal of the Korea Contents Association
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• v.16 no.1
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• pp.362-369
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• 2016

Recently, Last to check the security status of various medium and large bridge structures using various kinds of measurement equipment, but most of the methods are used to measure and check the displacement behavior of the bridge by a certain period. In this study, receive GPS satellite signals that can be observed in real time the whole region, a bridge to automatically measure the displacement and behavior characteristics of the structure in real-time in mm over the 24 hours, the measurement information and transmits the data to the wireless network, by making use, it was applied to the real-time monitoring system in connection with a bridge to be able to automatically notify GNSS fine displacement behavior. In fact, analysis and receives the measurement data to GNSS provided in the upper bridge of the middle and large-sized aging for this purpose, measuring USN and at the same time is converted into a three-dimensional position information of a test study was conducted to monitor the bridge displacement in real time. As a result, a vertical displacement of about 0.027~0.037m at the measurement time of day of the measurement point is that the repeated and confirmed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1483-1490
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• 2011

Electro-hydrostatic actuators(EHAs), which are usually composed of a direct motor-driven hydraulic pump and a cylinder, have been widely adopted as aircraft actuation systems because of their benefits in terms of improved efficiency, weight savings and the fact that they use a standalone power source. Since the recent trend in construction vehicles has been focus on energy savings in their hydraulic systems, EHAs are expected to be potential substitutes for conventional power transmission, since they are capable of energy recovery as well as highly efficient pump control. In this paper, the start and stop characteristics of EHAs were investigated through cracking pressure analysis of the pilot-operated check valve(PCV), which enables the cylinder to standstill against an external load with no holding effort from the hydraulic pump. A mathematical model that includes the load dynamics and the EHA's internal hydraulic circuit was derived for simulation with the MATLAB Simulink package. This model verified the PCV's opening and closing sequence, which in turn affects the EHA's start and stop characteristics.