• Journal of Arbitration Studies
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• v.8 no.1
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• pp.269-291
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• 1998

Change of circumstances subsequent to formation of international business contract raises two issues on both parties' obligation to perform business transaction concerned. One is impossibility of performance due to events beyond control of parties and the other is adaption of contract. In Anglo-American Law such an impossibility of performance is provided by the doctrine of Frustration and the doctrine of Practicability(UCC 2-615). In practice a "force majeure" clause should be included in contract defining the parties' mutual rights and duties if certain events beyond their control occur to safeguard themselves against possible impossibility. On the other hand the tendency of international trade is that alongside sales contracts, there are contract for supplies, for furnishing raw materials, for building industrial complexes, and transferring technology. One characteristic of these agreements is their duration. For in order to carry out these agreements, it is necessary to complete a series of closely interrelated operations which, in the normal course of events, take place over a number of years. It is often difficult for the parties, when finalizing their contract, to have a full grasp of all of the factors governing their relations. With a view to resolving difficulties such as compromise the continuous performance of a contract, parties may insert a regulatory clause in their contract providing for intervention by a third person after stating in specific and detailed fashion the circumstances in which their contract may be adapted.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.916-924
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• 2015

Electromagnetic Interference (EMI) is a system to system or environment to system phenomenon. The literature survey proved that the Randomized Pulse Width Modulation (RPWM) technique is a promising technique to reduce EMI. A new Constant Trailing Edge, Randomized Pulse Width Modulation (CTERPWM) technique is proposed in this paper. The effect of the proposed RPWM technique for mitigation of conducted-EMI on Cuk converter operating in Continuous Conduction Mode (CCM) is simulated and tested. In this paper, the analytical expressions for the Power Spectral Density (PSD) are derived for the proposed RPWM technique and are validated by experimental measurements. The effectiveness of the proposed RPWM technique on the mitigation of conducted-EMI is verified comparing simulation and experimental results and it is identified that both the results are almost similar with allowable experimental deviations. The comparative investigation proves that the proposed RPWM technique can mitigate and spread the dominant peaks of conducted-EMI over the complete spectrum for the Cuk converter. Based on the investigation the CTERPWM technique is recommended for adoption.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.393-396
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• 2008

Propellant consumption control for space launch vehicle can be achieved by propellant utilization system (PUS) and tank depletion system (TDS). In the course of developing new space launch vehicles, the main target of design is on reducing of space launch vehicle weight, which results in increasing both specific impulse and payload weight. The weights of space launch vehicles are generally allocated to structure, propulsion system, and propellants loaded. The quantity of propellants filled in propellant tanks may be estimated with the propellants actually consumed by propulsion system to complete its mission and the propellants left on-board at the time of engine shut-off. To minimize the remaining quantity of propellants on-board the supplying propellants' O/F ratio should be controlled from the certain time before engine shutdown. To control an O/F ratio, a control system, which accurately measures and compares the remainder of propellants in tanks and pipes, should be needed. This paper solely dedicates its contents to explore the merits and demerits of various level sensor, which is one of the important elements for PUS and TDS, and the transmission and control of signals within space launch vehicle.

• Journal of Electrical Engineering and Technology
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• v.5 no.3
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• pp.468-476
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• 2010

This paper presents a direct single-stage power converter using single-phase isolated full-bridge converter modules, with inherent power factor correction (PFC) for a 12 kW switched mode power supply (SMPS). The advantages of the proposed converter are its simple control strategy, reduction in number of conversion stage, low input line current harmonics, and improvement in power factor. Analysis of the single-stage converter is carried out in continuous conduction mode of operation. Steady-state analysis of the proposed converter is conducted to obtain converter parameters. A systematic design procedure is also presented for a 12k W converter with a design example. The effect of load variation on SMPS is also studied in order to demonstrate the effectiveness of the proposed converter for the complete range of load conditions. A set of power quality indices on input ac mains for an SMPS fed from a single-stage converter is also presented for easy comparison of their performance.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.198-206
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• 2004

To ensure competitiveness in the modem automotive market, process and material planning should be performed concurrently with new car developments. In automotive general assembly shops, thus, new business workflows and supporting environments are inevitable to reduce the manufacturing preparation time in developing a new car in the manner of concurrent and collaborative engineering. Since complete material planning for a whole general assembly system is a huge and complex job, several planners should execute their planning jobs and share information. Therefore, each planner should provide others with his/her results with continuous on-line communication and cooperation. In this research, a web-based system for concurrent and collaborative process and material planning for automotive general assembly via 3D digital mock-up S/W is developed. By using this system, savings in time and cost of process and material planning are possible, and the reliability of the planning result is improved.

• Tunnel and Underground Space
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• v.5 no.2
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• pp.114-122
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• 1995

The principle and applications of GPR(Ground Penetrating Radear) are familiar to engineering geologists and geophsicists as very attractive technique for continuous high resolution images of the subsurface. However, the main limitation of GPR is obviously related to presence of clayey or silty conductive soils, resulting in complete attenuation of radar signals. This difficulty gives hesitation for the exploration of the deeper targets for example detecting bedrock, particularly in Korean situation that most regions have conductive overburden. In order to prove usefulness of geological survey with GPR in that situation, the technique was tried to investigate depth of bedrock under thick conductive overburden and the other geolocgical informations for the constructionof foundation in the Dongbu apartment site, Kimhae. The reflection patterns on the processed GPR sections are well correlated with the geotechnical units-bedrock, alluvium, landfill unit and their internal layer-boundaries of boring data before GPR survey, except upper contact of bedrock. The isopach maps of the geotechnical units for the 3-D interpretations are made from GPR sections. The maps provided useful geological information that bedrock was distributed as plain and valley with 22~27m depth under alluvium unit (this depth is 5~8 m deeper than drill log) and sedimentary layers subsided and bended along growth fault with NNE strike/15$^{\circ}$SE dip in alluvium unit.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.131-134
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• 2005

Anaerobic reductive dechlorination of tetrachloroethylene(PCE) to ethylene was investigated by performing laboratory experiments using semi-continuous flow two-in-series soil columns. The columns were packed with soils obtained from TCE-contaminated site in Korea. Site ground water containing lactate(as electron donor and/or carbon source) and PCE was pumped into the soil columns. During the first operation with a period of 50 days, injected mass ratio of lactate and PCE was 620:1 and incomplete reductive dechlorination of PCE to cis-DCE was observed in the columns. However, complete dechlorination of PCE to ethylene was observed when the mass ratio increased to 5,050:1 in the second operation, suggesting that the electron donor might be limited during the first operation period. During the degradation of cis-DCE to ethylene, the concentration of hydrogen was $22{\sim}29mM$. These positive results indicate that the TCE-contaminated groundwater investigated in this study could be remediated through biological anaerobic reductive dechlorination processes.

• Journal of Trauma and Injury
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• v.29 no.2
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• pp.37-42
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• 2016

Purpose: Arterial injury in children is a challenging problem for its special characteristics. It is rare even during warfare. This review described a personal experience in the management and outcome of acute pediatric arterial injuries of extremities. Methods: Thirty-six children below age of 13 years were studied during period from 2004 through 2014 in Iraq. Results: Male patients were 27 (75%) and female were 9 (25%). Seven to twelve years old was the most affected age group. The incidence of iatrogenic injuries was greater in infants and toddlers while penetrating injuries were the most common in older children. Upper limbs arteries were affected in 17 (47.2%) and lower limb in 19 (52.8%) patients. Hard signs were the commonest mode of presentation (83.3%). Lateral wall tear and complete transection were the most frequent types of arterial injury (36.1% and 27.8% respectively). The most frequent procedures performed were end-to-end anastomosis and lateral arteriorrhaphy. Surgical outcome was good. In 27 cases distal pulsations were regained. Seven cases had impalpable distal pulses but still viable limbs. Limb length discrepancy was detected in one case. One case was complicated with limb loss. No death was recorded. Conclusion: Arterial injuries in children are age related. The proper treatment of arterial injuries in children requires high index of suspicion, early operative intervention and continuous postoperative follow-up throughout years of active growth. Angiogram has a limited role as a diagnostic tool in acute arterial injuries.

• Journal of Chest Surgery
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• v.21 no.1
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• pp.169-174
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• 1988

Thoracic esophageal rupture caused by blunt trauma is often not recognized until late because of the vague symptoms in the initial state as well as its rare incidence, which can easily lead to fulminant mediastinitis with frequent fatal outcome. Once extensive mediastinitis occurs, the primary surgical repair of the esophageal tear is considered to be practically impossible. Various methods have been proposed for the management of these desperately ill patients, but no one provides an acceptable good result yet. The purpose of this article is to report the successful result obtained in the treatment of a patient with fulminant mediastinitis from traumatic esophageal rupture by continuous transesophageal irrigation. A 27 year-old male patient was brought to the emergency room of our hospital complaining of dyspnea and chest pain after blunt trauma. The diagnosis of esophageal rupture in the thorax was made late, about 46 hours after the initial injury, when mediastinitis had already progressed. The transesophageal irrigation method was immediately instituted which consisted of profuse transesophageal irrigation of the mediastinum with orally ingested fluid and/or by Levin tube, positioned proximal to the site of the rupture, and drainage of the irrigation fluid by thoracoscopically accurately positioned chest tubes connected to a well suctioning system. With subsiding inflammatory signs and symptoms, the esophagogram, obtained 54 days after the treatment, showed no evidence of the mediastinal leakage of contrast material which contrasted previous esophagograms with definitive dye collections in the mediastinum. Additional endoscopic finding confirmed complete healing of the esophageal mucosa, previously ruptured. He has been followed up without any problem until recently, 6 months after discharge.

• Earthquakes and Structures
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• v.19 no.4
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• pp.287-301
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• 2020

Fragility as one of the most effective methods to evaluate seismic performance, which is greatly affected by damage index. Taking a multi span continuous rigid frame offshore bridge as an example. Based on fragility and reliability theory, considering coupling effect of time-varying durability damage of materials and time-varying attenuation effect of damage index to analyze seismic performance of offshore bridges. Results show that IDA curve considering time-varying damage index is obviously below that without considering; area enclosed by IDA of 1# pier and X-axis under No.1 earthquake considering this effect is 96% of that without considering. Area enclosed by damage index of 1# pier and X-axis under serious damage with considering time-varying damage index is 90% of that without considering in service period. Time-varying damage index has a greater impact on short pier when ground motion intensity is small, while it has a great impact on high pier when the intensity is large. The area enclosed by fragility of bridge system and X-axis under complete destruction considering time-varying damage index is 165% of that without considering when reach designed service life. Therefore, time-varying attenuation effect of damage index has a great impact on seismic performance of bridge in service period.