• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.6
• /
• pp.453-458
• /
• 2016

CFRP (Carbon Fiber Reinforced Plastic) and CFRP-metal stacks have recently been widely used in the aerospace and automobile industries. When CFRP is machined by a brittle fracture mechanism, defect generation behaviors are different from those associated with metal cutting. The machining quality is strongly dependent on the properties of CFRP materials. Therefore, process control for CFRP machining is necessary to minimize the defects of differently manufactured CFRPs. In this study, defects in drilling of CFRP substrates with a variety of fiber directions and resin types are compared with respect to thrust force. An experimental study on material interface detection is carried out to investigate its benefits in process control.

• Journal of Chest Surgery
• /
• v.9 no.2
• /
• pp.276-286
• /
• 1976

Coarctation of the aorta is an important congenital cardiovascular defect,. which occurs in a significant number of persons. The basic anatomic defect is a localized deformity of the media, manifested by two types of strictures in the aorta: "true" coarctation and tubular hypoplasia. The zone of coarctation is characteristically located distal to the origin of left subclavian artery at or just beyond the insertion of the ligamentum arteriosum. It shortens life if untreated, but it can be corrected to render the patient functionally normal. Here we have a 2-year operative experiences with 3 cases of the aortic coarctation, two of hypoplastic type and one of postductal type, at age of 17 to 19 year old Korean, operated in 1965 and l968 at the National Medical Center. The purposes of this report are to describe the immediate and late effect of surgery, histopathologic bases and the rarity of this lesions in Korea.

• IE interfaces
• /
• v.18 no.1
• /
• pp.73-81
• /
• 2005

Injection molding has been widely used in producing plastic parts in large quantities. However, its productivity mainly depends on the expertise and experience of skilled workers because of the difficulty and complexity to determine a robust injection molding condition which is not influenced by the minor operational variation of an injection molding machine and produces good parts continuously. This study analyzes the defect types of the parts and proposes a support system to assist users in determining the robust process condition. The support system calculates the start condition from the information of an injection mold, the injection molding machine, the resin used, and the part. Through the iterative step which updates the condition using the defect information of the part tested, users can obtain the initial condition which produces the part without any problem for the first time. The support system also assists users in obtaining the robust condition from the initial condition using the technique of experimental design. To prove the validity of the support system, this study implements it in the control panel of the injection molding machine.

• Journal of the Korean Society for Railway
• /
• v.2 no.2
• /
• pp.21-30
• /
• 1999

This study proposes the analysis and evaluation method of time series ultrasonic signal using the phase space-frequency domain. Features extracted from time series signal analyze quantitatively characteristics of weld defects. For this purpose, analysis objectives in this study are features of time domain and frequency domain. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics resulting from distance shifts such as parts of head and flange even though the types of defects are identified. These differences in characteristics of weld defects enables the evaluation of unique characteristics of defects in the weld zone. In quantitative fractal feature extraction, feature values of 3.848 in the case of part of head(crack) and 4.102 in the case of part of web(side hole) and 3.711 in the case of part of flange(crack) were proposed on the basis of fractal dimension. Proposed phase space-frequency domain method in this study can integrity evaluation for defect signals of rail weld zone such as side hole and crack.

• Journal of Chest Surgery
• /
• v.26 no.2
• /
• pp.129-134
• /
• 1993

We compared postoperative results according to the different surgical approach in 180 cases of isolated ventricular septal defects operated at the department of Thoracic and Cardiovascular Surgery in Kyungpook University Hospital from January 1987 to December 1991. Of the 180 cases, 109 were males and 71 females, age ranging from 6 months to 15 years (mean: 5.6 years) and body weight ranging from 6 to 52㎏(mean : 20㎏). According to Soto's classification, perimembranous types were comprised of 119 cases (66％), doubly committed subarterial type 49 cases(27％), and muscular type 12 cases(7％). Patients were divided into three groups according to the incision methods: right atriotomy group (39％), right ventriculotomy group (47％), and pulmonary arteriotomy group (14％). The mean aortic cross clamp time was shorter in right atriotomy group (39 min.) than right ventriculotomy group (79min.) in the cases of large perimembranous VSD (P＜0.001). Spontanous recovery rate of cardiac rhythm after VSD closure was higher in right atriotomy group (51％) than right ventriculotomy group (32％) in the cases of perimembranous VSD (P＜0.05). The incidence of postoperative RBBB was 17.6％ with no statistical differences between right atriotomy group(17.9％) and right ventriculotomy group(19.2％). Overall mortality rate was 5.6％(10 cases) with no significant differences according to surgical approach.

• Journal of the Korean institute of surface engineering
• /
• v.51 no.1
• /
• pp.1-10
• /
• 2018

Anodic oxidation treatment of metals is one of typical surface finishing methods which has been used for improving surface appearance, bioactivity, adhesion with paints and the resistances to corrosion and/or abrasion. This article provides fundamental principle, type and characteristics of the anodic oxidation treatment methods, including anodizing method and plasma electrolytic oxidation (PEO) method. The anodic oxidation can form thick oxide films on the metal surface by electrochemical reactions under the application of electric current and voltage between the working electrode and auxiliary electrode. The anodic oxide films are classified into two types of barrier type and porous type. The porous anodic oxide films include a porous anodizing film containing regular pores, nanotubes and PEO films containing irregular pores with different sizes and shapes. Thickness and defect density of the anodic oxide films are important factors which affect the corrosion resistance of metals. The anodic oxide film thickness is limited by how fast ions can migrate through the anodic oxide film. Defect density in the anodic oxide film is dependent upon alloying elements and second-phase particles in the alloys. In this article, the principle and mechanisms of formation and growth of anodic oxide films on metals are described.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.5 no.1
• /
• pp.18-22
• /
• 2005

Pompe disease is a genetic disorder caused by a deficiency of acid ${\alpha}$-glucosidase (GAA). This enzyme defect results in lysosomal glycogen accumulation in multiple tissues and cell types, with cardiac, skeletal, and smooth muscle cells the most seriously affected. Infantile-onset Pompe disease is uniformly lethal. Affected infants present in the first few months of life with hypotonia, generalized muscle weakness, and a hypertrophic cardiomyopathy, followed by death from cardiorespiratory failure or respiratory infection, usually by 1 year of age. Late-onset forms is characterized by a lack of severe cardiac involvement and a less severe short-term prognosis. Enzyme replacement therapy for Pompe disease is intended to address directly the underlying metabolic defect via intravenous infusions of recombinant human GAA to provide the missing enzyme. We experienced one case of Pompe disease in 3-years old boy that has improved his exercise ability and cardiac function after GAA enzyme replacement therapy.

• Archives of Reconstructive Microsurgery
• /
• v.13 no.1
• /
• pp.36-42
• /
• 2004

Materials and Methods: We studied 50 cases of peroneal perforating branch about branching pattern, course, length of vascular pedicle, and perforating level of the perforating cutaneous branches from Oct. 1985 to November 2003 by doppler flow meter and intraoperative findings. Results: 1) The perforating cutaneous branches were classified into four types, the Straight Branch (27cases), the Proximal Oblique Branch (11cases), the Branch from Muscular Artery (10cases), the Distal Oblique Branch(2 cases) respectively. The most common patten was Straight Branch, that was 54%. 2) There were 3 pathways of these branches, the most common one passed between the Soleus and Peroneus muscles(34 cases, 68%) 3) The length of vascular pedicle in Buoy Flap was variable from from 3 cm to 15 cm, but 32 cases(64%) were distributed between 5 cm and 6 cm. 4) The perforating level of branches were 5.9 cm in average from fibular neck to subcutaneous perforator artery 5) Peroneal Buoy Flap in possible to reconstruct both seperated bone and skin defect in some distance by One-Stage Operation and we can harvest maximal $8{\times}16cm$ sized flap in one perforating artery. If we include more two perforating artery, we get more wide flap which can cover large defect.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.267-270
• /
• 2005

Finite element model of pressurized water reactor internals were obtained using ANSYS software package to analyze dynamic characteristics. The pressure vessel, hold-down ring, alinement key, core support barrel(CSB), upper guide structure(UGS) and fluid gap were fully modeled using structural solid element(SOLID45) and fluid element(FLUID80) which is one of element types. Also modal analysis using the above finite element model has been performed. As a result, it was found that the fundamental beam mode natural frequency of the CSB were 8.2 Hz, the shell mode one 14.5 Hz. To verify the Finite Element Analysis(FEA), we compare the analysis result with experimental data that is obtained from the plant IVMS(internal Vibration Monitoring System). The experimental results are good agreement with the FEA model.

• Archives of Plastic Surgery
• /
• v.50 no.4
• /
• pp.409-414
• /
• 2023

The anterior interosseous artery (AIA) perforator flap is not commonly used in hand dorsum reconstruction compared with alternatives. However, it is a versatile flap with several advantages. Literature on the AIA perforator flap is based on the dorsal septocutaneous branch (DSB), which branches from the AIA and passes through fascia between the extensor pollicis longus (EPL) and extensor pollicis brevis muscles. In the described case, the authors reconstructed a hand dorsum defect in a 78-year-old man using an AIA perforator flap with double perforators supplied by the DSB and a new perforator branching from the distal than DSB. No complication was encountered, and the flap survived completely. A retrospective computed tomography review revealed the presence of the new perforator in 14 of 21 patients. Two types of new perforator were observed. One passed through the ulnar side of the extensor indicis proprius (EIP) muscle and penetrated fascia between the extensor digitorum minimi and extensor digitorum communis tendons, whereas the other passed between the EPL and EIP muscles. This report describes the anatomical location and clinical application of the new AIA perforators. The double perforators-based AIA flap provides a straightforward, reliable means of reconstructing hand dorsum defects.