• Journal of the Korean Institute of Navigation
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• v.15 no.4
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• pp.27-39
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• 1991

One practical method has already been proposed for predicting the characteristics of ship manoeuvring motions at relatively high advance speed [19]. Howeverf, this method can hardly be applied to motions of ships in starting, stopping, backing and slow steaming conditions, even though such extensive motions are of vital importance from a safety point of view particularly in harbour areas. The method presented here aims at predicting the characteristics of ship manoeuvring at low advance speed, which covers starting, stopping, backing and slow steaming conditions. The force mathematical models at large angles of incidence to the hull as well as under the wide range of propeller operations are formulated. Simulations of various manoeuvres at low advance speed are carried out for two types of merchant ship, I.e. a LNGC and a VLCC. Comparisons between simulations and corresponding full-scale measurements [10], [15] or free-running model tests [6],[10] provide a first verification of the proposed mathematical models.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.16 no.1
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• pp.81-91
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• 1986

The author obtained the trans cranial radiographs of right and left side and the individualized lateral tomograms of right and left side after the analysis of submental vertex view from 8 young adults of 25-32 years with normal occlusion. The condylar position from 32 radiographs of normal TMJs were assessed with each measurement methods. All datas from these analyses were recorded and statistically processed with CYBER computer system. The results were obtained as follows. 1. In each measurement methods, the area measurements using the midpoint fossa and the midpoint condyle revealed the hightest concordance rate between the radiographic pairs. 2. In the subjective evaluation, the qualitative concordance existed in 44% and the full concordance existed in 25%, so it was found that concordance rates were relatively low between the radiographic pairs. 3. In each measurement methods, the area measurement using the midpoint fossa revealed the strongest correlation between the radiographic pairs. 4. The correlations between the area measurement using the midpoint fossa and subjective valuation revealed relatively strong value which is 0.926 in the trans cranial radiographic series and the lowest value which is 0.743 in the tomographic series.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.4
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• pp.384-394
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• 1999

This paper deals with a fixed frequency full-bridge inverter type DC-DC high-power converter with high frequency high voltage(HFHV) transformer-coupled stage, which operates under quasi-resonant ZVS transition priciple in spite of a wide PWM-based voltage regulation processing and largely-changed load conditions. This multi-resonant(MR) converter topology is composed of a series capacitor-connected parallel resonant tank which makes the most of parasitic circuit reactive components of HFHV transformer and two additional quasi-resonant pole circuits incorporated into the bridge legs. The soft-switching operation and practical efficacy of this new converter circuit using the latest IGBTs are actually ascertained through 50kV trially-produced converter system operating using 20kHz/30kHz high voltage(HV) transformers which is applied for driving the diagnostic HV X-ray tube load in medical equipments. It is proved from a practical point of view that the switching losses of IGBTs and their electrical dynamic stresses relating to EMI noise can be considerably reduced under a high frequency(HF) switching-based phase-shift PWM control process for a load setting requirements.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.585-593
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• 2011

Actual fire test under a laboratory and fire simulation by using computer are considered into main methodology in order to estimate and predict fire size of railway train. Even if practical fire size could be obtained from the full-model railway car test such as a large scale cone-calorimeter test, it is not always possible and realistic due to that expensive cost and attendant dangers could in no way be negligible. In this point of view, fire simulation analysis method based on the computational fluid dynamics could be proposed as an alternative and it seems to be also efficient and reasonable. However, simulation results have to be verified and validated in accordance with the proper procedure including comparing analysis with the actual fire test. In this paper, fire load and growth aspect was investigated through the room corner test (ISO 9705) for the mock-up model of the actual railway car. Then, it was compared with the output data derived from the simulation by using Pyrolysis Model of the FDS (Fire Dynamics Simulator, by NIST) for the exact same domain and condition corresponding with pre-performed room-corner test. This preliminary verified and validated fire modeling method could enhance the reliability of output data derived from the fire simulation under the similar domain and condition.

• Archives of Craniofacial Surgery
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• v.17 no.1
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• pp.28-30
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• 2016

Major maxillofacial bone injury itself can be life threatening from both cardiovascular point of view, as well as airway obstruction. Significant hemorrhage from facial fracture is an uncommon occurrence, and there is little in the literature to guide the management of these patients. We report a 73-year-old male driver who was transported to our hospital after a motor vehicle collision. The patient was hypotensive and tachycardic at presentation and required active fluid resuscitation and transfusion. The patient was intubated to protect the airway. All external attempts to control the bleeding, from packing to fracture reduction, were unsuccessful. Emergency angiogram revealed the bleeding to originate from terminal branches of the sphenopalatine artery, which were embolized. This was associated with cessation of bleeding and stabilization of vital signs. Despite the age and severity of injury, the patient recovered well and was discharged home at 3 months with full employment. In facial trauma patients with intractable bleeding, transcatheter arterial embolization should be considered early in the course of management to decrease mortality rate.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.6
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• pp.39-51
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• 1996

In the turning maneuver of the vehicle, its motion is mainly dependent on the genuine steering characteristics in view of the directional stability for stable turning ability. The under steer vehicle has an ability to maintain its own directonal performance for unknown external disturbances to some extent. From a few years ago, in order to acquire the more enhanced handling performance, some types of four wheel steering vehicle were considered and constructed. And, various rear wheel control logics for external disturbances has not been suggested. For this reason, in this posed rear wheel control logic is based on the yaw rate feed back type and is slightly modified by an yaw rate tuning factor for more stable turning performance. And an external disturbance is defined as a motivation of the additional yaw rate in the center of gravity by an uncertain input. In this study, an external disturbance is applied to the vehicle as a form of the additional yawing moment. Finally, the proposed rear wheel control logic is tested on the multi-body analysis software(ADAMS). J-turn and double lane change test are performed for the validation of the control logic.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.227-230
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• 2003

In this paper, a full bridge edge-resonant zero voltage mode based soft-switching PWM DC-DC power converter with a high frequency center tapped transformer link stage is presented from a practical point of view. The power MOSFETS operating as synchronous rectifier devices are implemented in the rectifier center tapped stage to reduce conduction power losses and also to extend the transformer primary side power MOSFETS ZVS commutation area from the rated to zero-load without a requirement of a magnetizing current. The steady-state operation of this phase-shift PWM controlled power converter is described in comparison with a conventional ZVS phase-shift PWM DC-DC converter using the diodes rectifier. Moreover, the experimental results of the switching power losses analysis are evaluated and discussed in this paper. The practical effectiveness of the ZVS phase-shift PWM DC-DC power converter treated here is actually proved by using 2.5kW-32kHz breadboard circuit. An actual efficiency of this converter is estimated in experiment and is achieved as 97$\%$ at maximum.

• The Journal of Korea CHUNA Manual Medicine
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• v.5 no.1
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• pp.205-211
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• 2004

Objective : This study is designed to provide clinical data about patients of scoliosis for clinicians. Methods : We investigated 112 patients who have signs and symptoms of scoliosis. visited Vertebral -Joint Center of Conmaul Oriental Medical Hospital from January 2003 to July 2004. We measured Cobb's angle in the 112 patients' X-ray of full spine AP and lateral view and also analyzed age, sex, chief complaints. Results : 1. We investigated 72 female and 40 male patients. The most common distribution of age was 20's in both sex. 2. In the scoliosis angle : The average scoliosis angle was $9.27^{\circ}{\pm}6.06^{\circ}$ in 112 patients. The average scoliosis angle of 40 male patients was$8.9^{\circ}{\pm}6.77^{\circ}$. The average scoliosis angle of 72 female patients was $9.48^{\circ}{\pm}5.67^{\circ}$. 3. The most common region of scoliosis was thoracic spine with 37 patients. 4. The most common chief complaint was low back pain with 69 patients. In the 48 patients. self awareness of scoliosis was included in the chief complaint.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.112-118
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• 2013

Formula race car is generally recognized as a vehicle which is optimally designed for on-road race track with the regulations of race host bodies. Especially, the uprights of suspension system decisively have effects on the performance of cornering and stability of race car's driving performance, which are very important factors in the design of race car. This paper is a study of optimal upright design of F1800 grade formula race car which are normally used in professional race circuit in Korea. To design optimally the front upright of F1800 formula race car, Taguchi's orthogonal array, which is known for more useful method than full factorial design experimental method in cost and time, is used with CAE method such as FEM analysis. And the result of this paper shows that Taguchi's orthogonal array employed for this optimal design is very useful for designing the front upright of race car by minimizing its weight as well as keeping its safety factor as enough as designer wants in the view of quality, cost and delivery at the early design step.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.188-193
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• 1999

Technology of GIS evolved as a means of assembling and analyzing diverse spatial data. Many systems have been developed, and almost of systems are proprietary. There is a lots of lack of interoperability and reusability between them. This paper describes the development of Open GIS component software. The developing system have an end in view of GIS tool software which is interoperable and reusable. To increase the interoperability and reusability, the system is based on the OGC(Open GIS Consortium)'s Open GIS Simple Features Specification for OLE/COM. The OGC's specification is announced to increasing the full interoperability of various geospatial data and geoprocessing resources. With the Open specification, component based software ensures the reusability. We implement three kinds of component: Geometry component, Spatial Reference System Component, and MapBase Component. The first two components are compatible to the OGC's specification and the third one is designed to GIS tool software for variant GIS applications. The Open GIS component software system is developed on object-oriented computing environment, ATL/COM and Visual C++. As we made application programs using Visual Basic, the advantages of component based Open GIS software was proved.