• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.32-40
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• 2019

This study analyzed operating condition and the problems of damage compensation insunace (property insurance) for qualified architect and derived some suggsetions for improvement. The Certified Architects Act requires all building design and construction supervision to buy property insurance. This study proposes following suggestions to solve problems of current architect property insurance. Firstly, we need to increase the insurance purchasing rate of damage compensation insurance for qualified architect. It is necessary to clearly specify the matters concerning the submission of insurance policies by the architects, which is currently carried out by the Minister's official letter, in the form of official announcement. Secondly, proper insured amount should be adjusted. In order to insured substantial compensation capacity, total amount of insurance should be enlarged. Thirdly, the insurance period should be extended to one year after completion of building to allow compensation for accidents due to design negligence. Generally, the design defect can mostly be identified within one year after completion. Fourthly, insurance coverage should be extended. In the long run, it is essential to enlarge the scope of the security not only to property damage but also to human losses. Finally, an accident record sharing system should be established among insurance companies, so that proper insurance premiums or discounts can be made based on the system.

• Journal of Chest Surgery
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• v.31 no.6
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• pp.576-580
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• 1998

This study is to clarify the results of atrial septal defect(ASD) repair and mitral valve surgery through right anterolateral thoracotomy since 1989, and those of more generalized application of minimal invasive cardiac surgery since August 1997. We retrospectively analyzed the results of open heart surgery(OHS) through other than full sternotomy carried out until October 1997. There were 28 cases of OHS done through right anterolateral thoracotomy(17 cases of ASD, 4 cases of mitral valve repair, 6 cases of mitral valve replacement, and 1 redo mitral and tricuspid valve repalcement) which has demonstrated no surgical mortality or morbidity except only 1 case of reoperation for bleeding. During the period between August and October 1997, we performed near routine application of upper sternotomy or transverse sternotomy in aortic valve cases and routine application of minimal incision in cases with ASD and there was no evidence of early and late complications associated with this approach. We conclude that OHS with the use of minimal incisions is very safe, cosmetically excellent, and superior in terms of the amount of bleeding. The indication for minimal incision, therefore, should be extended afterwards.

• Journal of Chest Surgery
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• v.7 no.2
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• pp.163-168
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• 1974

Five cases of traumatic diaphragmatic hernia were repaired in the Department of Thoracic Surgery, Seoul National University Hospital, during the period from 1967 to 1974. The first case, a 14-year aid girl, was diagnosed as diaphragmatic hernia during laparotomy because of jejunal perforation 3 days after traffic accident. Herniated stomach, transverse colon, spleen and left lobe of the liver were repositioned and the diaphragmatic rupture on left posterolateral portion was repaired with two layers of nonabsorbable sutures by transthoracic approach. The second case, a 26-year old man,was diagnosed immediately after traffic accident at a local clinic and transferred to this hospital 24 hours later. Herniated stomach, transverse colon and jejunum were repositioned amd diaphragmatic rupture,about 9 cm in length,from the posterolat.edge to the base of pericardium was sutured in two layers. The third case, a 26-year old man who had stab wound on the left lower lateral chest two years ago,was admitted with sudden abdominal pain and vomiting. Upper gastrointestinal series with barium meal revealed diaphragmatic hernia. The herniated stomach and transverse colon through the defect,about 3.5cm in diameter, at anterolateral portion on the left side,were repositioned and repaired with two layers of nonabsorbable sutures. The forth case, a 26-year old man, sustained blunt trauma to the chest by a roller and was transferred to the emergency room complaining of dyspnea 40 minutes after the accident. The diaphragmatic rupture extended from left midaxillary line to contralateral anterior axillary line,about 20cm long, at anterior portion of diaphragm, which was repaired with two layers, of nonabsorbable sutures. The fifth case, a 4-year old girl, had two separate diaphragmatic ruptures on both sides, which were caused by traffic accident. Immediate upper gastrointestinal series after injury showed herniated stomach, colon and spleen into left Chest cavity. Another small rupture with anterior edge of right lobe of the liver in chest cavity was noted. These were repaired with non-absorbable sutures via thoracotomy.

• International Journal of Automotive Technology
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• v.5 no.3
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• pp.215-219
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• 2004

A vehicle structure needs to be more precisely analyzed because of complexities and varieties. Structural fatigue which is generated by fluctuations of stresses during the service life of a mechanical system is the primary concern in the structural design for safety. A fatigue life is difficult to obtain in structural components during the service life of mechanical systems since the fluctuating stress contributes to fatigue. This study introduces new procedures to measure the lethargy coefficient and to predict the fatigue life of a mechanical structure by using molecular dynamic simulation. A lethargy coefficient is the total defect-estimating coefficient, which was obtained by using the results of a simple tensile test in this study. With this lethargy coefficient, fatigue life was estimated. The proposed method will be useful in predicting the fatigue life of a structurally-modified vehicle design. The effectiveness of the proposed method using lethargy coefficient measurement to predict the fatigue life of a structure was examined by applying this method to predict the fatigue life of SS41 steel, used extensively as material of vehicle structures. Two types of specimen such as pre-cracked plate and simple plate is discussed. equation of fatigue life using the lethargy coefficient and failure time, both obtained from a simple tensile test, will be useful in engineering. This measurement and prediction technology will be extended for use in analysis of any geometric shapes of modified automotive structures.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1204-1208
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• 2000

Objectives : At the closure of the transsphenoidal approach(TSA), the proper sellar floor reconstruction plays an important role in preventing postoperative complications. The septal cartilage, perpendicular plate of nasal septum, and the sphenoid sinus bone are usually used to repair the sellar floor as a bone splint. The authors evaluate the usefulness of a silicone plate as a substitute for bone splint to close a defect of the sellar floor. Materials and Methods : A silicone plate was used to repair the sellar floor in 7 patients with sellar lesions which included four pituitary adenomas, two Rathke's cleft cysts and one metastatic tumor. Among seven cases, five cases underwent a standard TSAs and two received a extended TSAs. The trajectories of the approach were sublabial in four cases and endonasal routes in three cases. The silicone plate for implantation was cut to a size of slightly larger than that of bone window and inserted with a three-pronged fork, and then adjusted precisely. Results : In six patients, there were no complications which related to sellar floor reconstruction. A postoperative cerebrospinal fluid(CSF) rhinorrhea was observed in one patient with pituitary macroadenoma. Conclusions : From the authors' experience, the advantages of the silicone plate are its simplicity of molding to fit any size of sellar floor defects, and easy detection of previously created bone window at reoperation.

• The KIPS Transactions:PartD
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• v.9D no.2
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• pp.313-322
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• 2002

Multimedia conference systems are classified into the tightly coupled conference and the loosely-coupled conference, the former is a peer-to-peer-conference or multi-point-conference based un the ITU-T H.323 standard, and the latter is the H.332 standard extended from the ITU-T H.323 standard. Loosely-coupled conference based on the H.332 standard is composed of small participants with the capacity of the send-receive mode and large participants with the capacity of the receive-only mode. In the H.332 conference, a subject and a media type of the multimedia conference is pre-announced for conquest of the difficulty of capability negotiation, and used SDP of IETF for that. Therefore, the H.332-conference can conquer a defect of the H.323 multimedia conference scalability. This paper analyzes H.332 standard for the loosely-coupled conference and describes an implementation of the H.332 multimedia conference systems.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.2
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• pp.461-470
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• 1998

The comparative detectability of the artificial periapical defects among Ektaspeed Plus film. digitized and digora images was evaluated. The artifical defects were made in the cancellous bone and cancellous-cortical junction with the size of 1.0×0.8mm², 1.4×1.1mm² and 2.8×2.2mm². The defects in cancellous-cortical junction extended into cortical bone with the depth of 0, 0.5 and 1.0 mm. The results were as follows : 1. In junctional defects Ektaspeed Plus film for 2.8×12.2mm² defect showed the highest detectability. But significant difference were only found between Ektaspeed Plus films and digitized images (p<0.05). 2. Almost all defects within cacellous bone were not detected except a few digitized and Digora images for the size of 2.8×2.2mm². Digora images for them showed significant differences with Ektaspeed Plus films and digitized images (p<0.05). 3. The sensitinity of all imaging modalities were 0.9 or 1.0 in junctional defects for the size of 1.4×2.2mm² and 2.8×2.2mm². For cancellous defects, Digora image showed the highest sensitivity of 0.6 for the size of 2.8×2.2mm². 4. Significant differences for change of exposure time were found in most group of Ektaspeed Plus films and digitized images (p<0.05) . But there was no significant differences in Digora images for cacellous defects.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.108-115
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• 2009

In metal forming technologies, the stamping process is one of the significant manufacturing processes to produce sheet metal components. It is important to design stamping process which can produce sound products without defect such as fracture and wrinkle. The objective of this study is to propose the feasible formability diagram which denotes the safe region without fracture and wrinkle for effective design of stamping process. To determine the feasible formability diagram, FE-analyses were firstly performed for the combinations of process parameters and then the characteristic values for fracture and wrinkle were estimated from the results of FE-analyses based on forming limit diagram. The characteristic values were extended through training of the artificial neural network. The feasible formability diagram was finally determined for various combinations of process parameters. The stamping process of turret suspension to support suspension module was taken as an example to verify the effectiveness of feasible formability diagram. The results of FE-analyses for process conditions within fracture and wrinkle as well as safe regions were in good agreement with experimental ones.

• Tribology and Lubricants
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• v.31 no.3
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• pp.109-124
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• 2015

This paper presents a wear analysis procedure for the journal bearings on a stripped-down single-cylinder engine during start-up and coast-down by motoring. A journal bearing is in the mixed elastohydrodynamic (EHL) lubrication region when the shaft speed is less than the corresponding lift-off speed. Below the lift-off speed, a wear scar can form on bearing surfaces. In part 1 of this paper, we develop the appropriate formulations and the calculation procedure for the analysis. Specifically, we formulate an equation for modified film thickness in a journal bearing considering the additional wear volume. In order to obtain the modified specific wear rate induced by the modified Archard’s wear coefficient, we utilized the extended non-dimensional diagram for the specific wear rate, k, the fractional film defect coefficient, Ψ and the asperity load sharing factor, γ₂. This asperity load sharing factor is newly calculated by setting the Zhao-Maietta-Chang (ZMC) asperity contact pressure equation coupled with the central film thickness equation derived by using the ZMC asperity contact model equal to the modified central contact pressure derived by using the central (or maximum) contact pressure at the dry rough line-contact configuration. We can use the procedure introduced in this paper to determine the lifetime (or longterm) linear wear in radial journal bearings that is a result of repeated stop-start cycles.

• Journal of Korean Society for Quality Management
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• v.48 no.2
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• pp.297-307
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• 2020

Purpose: The purpose of this study is to analyze the factors that affect ammunition performance by applying data mining techniques to the Ammunition Stockpile Reliability Program (ASRP) data of the 155mm propelling charge. Methods: The ASRP data from 1999 to 2017 have been utilized. Logistic regression and decision tree analysis were used to investigate the factors that affect performance of ammunition. The performance evaluation of each model was conducted through comparison with an artificial neural networks(ANN) model. Results: The results of this study are as follows; logistic regression and the decision tree analysis showed that major defect rate of visual inspection is the most significant factor. Also, muzzle velocity by base charge and muzzle velocity by increment charge are also among the significant factors affecting the performance of 155mm propelling charge. To validate the logistic regression and decision tree models, their classification accuracies have been compared with the results of an ANN model. The results indicate that the logistic regression and decision tree models show sufficient performance which conforms the validity of the models. Conclusion: The main contribution of this paper is that, to our best knowledge, it is the first attempt at identifying the significant factors of ASPR data by using data mining techniques. The approaches suggested in the paper could also be extended to other types ammunition data.