• Journal of the Microelectronics and Packaging Society
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• v.20 no.4
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• pp.7-11
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• 2013

As thermosonic ball bonding is developed for more and more advanced applications in the electronic packaging industry, the control of process stresses induced on the integrated circuits becomes more important. If Cu bonding wire is used instead of Au wire, larger ultrasonic levels are common during bonding. For advanced microchips the use of Cu based wire is risky because the ultrasonic stresses can cause chip damage. This risk needs to be managed by e.g. the use of ultrasound during the impact stage of the ball on the pad ("pre-bleed") as it can reduce the strain hardening effect, which leads to a softer deformed ball that can be bonded with less ultrasound. To find the best profiles of ultrasound during impact, a numerical model is reported for ultrasonic bonding with capillary dynamics combined with a geometrical model describing ball deformation based on volume conservation and stress balance. This leads to an efficient procedure of ball bond modelling bypassing plasticity and contact pairs. The ultrasonic force and average stress at the bond zone are extracted from the numerical experiments for a $50{\mu}m$ diameter free air ball deformed by a capillary with a hole diameter of $35{\mu}m$ at the tip, a chamfer diameter of $51{\mu}m$, a chamfer angle of $90^{\circ}$, and a face angle of $1^{\circ}$. An upper limit of the ultrasonic amplitude during impact is derived below which the ultrasonic shear stress at the interface is not higher than 120 MPa, which can be recommended for low stress bonding.

• Advances in pediatric surgery
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• v.2 no.2
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• pp.151-155
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• 1996

Hyperimmunoglobulin E syndrome is a relatively rare primary immunodeficiency syndrome characterized by recurrent infection, abscess formation and marked elevation of serum IgE level. The common infectious organism is Staphylococcus aureus and recurrent infection indicates some defects in the immunologic system. Although the infection can affect various organs, gastrointestinal tract involvement is rare and only one case of colon perforation has been previously reproted. Herein we report another one case of colon perforation which ocurred in an 8-year-old girl with hyper immunoglobulin E syndrome. The patient was admitted to the hospital due to an abscess on right neck. The diagnosis of hyper immunoglobulin E syndrome was made because she had eczematoid dermatitis on the face, pneumatocele on left upper lung field and markedly elevated serum IgE level(>15,000 IU/ml) with a past histories of frequent scalp abscesses and otitis media. Abdominal pain developed on the 13th day of admission and abdominal plain X-ray revealed free air. An exploratory laparatomy was performed and two free perforations of the transverse colon were noted. Segmental resection and double barrel colostomy were performed. Colostomy closure was done 4 month later and she had no gastrointestinal problem during a follow up period of 15 months.

• Archives of design research
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• v.15 no.2
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• pp.101-114
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• 2002

On the threshold of year 2000, the elderly account for more than 7% of the whole population in Korea, which means that the nation is greeting welcoming an aging society. Accordingly, it is expected that silver businesses and services targeted at the silver generation will prosper with "silver advertising design" becoming active. Under such circumstances, this study was aimed at reviewing the recent silver marketing advertisements in terms of their cultural and moral implications, and thereby, redefining and reestablishing the status of silver consumers to help them find their identity, aware of marketing activities and therewith, establish their "consumer sovereignty". This study consists in large of 5 chapters. The introduction parr describes background, purpose, method and scope of the study. The first chapter reviews the silver marketing theories. The second chapter classifies the silver marketing advertisement positioning of four style - upper classes style, effloresce progress style, self- sufficiency style, dependent style - and reviews the expression strategy of each positioning. The third chapter examines the domestic conditions of silver marketing advertisements for each positioning type classified. The fourth chapter designs the ′creative′of silver marketing advertisements and suggests the methods thereof. The analysis of ′creative′was tested in terms of graphic gestaltung, and how the sliver marketing advertisement positioning should be discerned depending on silver generation consumer′s characteristics was discussed. The fifth chapter puts forwards the suggestions for the ′creative′ strategies to enhance the effects of the silver marketing advertisements, based on the preceding discussions. In addition, the Perspective into the keyword of 21 st century or "silver design" is discussed, together with the limitations of this study. It is hoped that this stuffy will be conducive to our efforts to face the upcoming′age\ulcorner society′more effectively. To this end, this study discusses the "silver advertising design" in light of ′societal concepts′and ′customer-oriented value′, and thus, explores some creative presentation strategies whereby individual companies interests and social or public interests can be compromised through ′creative activities′ and ′equal-value consumerism′ for an ultimately effective management strategies for silver businesses and services.

• Journal of the Korean Ceramic Society
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• v.35 no.2
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• pp.172-179
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• 1998

Valve lifter namely tappet is supported by lifter hole which is located upper side of camshaft in cylinder block transforms rotatic mvement of camshaft into linear movement and helps to open and shut the en-gine valve as an engine parts. The face of valve lifter which is continuously contacting with camshaft brings about abnormal wears such as unfair wear and early wear because it is severely loaded in the valve train system. These wears act as a defect like over-clearance and cause imperfect combustion of fuel during the valve lifting in the combustion chamber. Consequently this imperfect combustion makes the engine out-put decrease and has cause on air pollution. To prevent these wears therefore The valve lifter cast in me-tal developed into SiC ceramics valve lifter which has an excellence in wear and impact resistance As a results the optimum process conditions like injection condition mixture ratio and debonding process could be established. After sintering fine-sinered dual microstructure in which prior ${\alpha}$-SiC matches well with new SiC(${\beta}$-SiC) produced by reaction among the ${\alpha}$-SiC carbon and silicon was obtained. Based on the study it is verified that mechanical properties of SiC valve lifter are excellent in Vickers hardness 1100-1200 bending strength (300-350 Pa) fracture toughness(1.5-1.7 Mpa$.$m1/2) Through engine dynamo test-ing SiC valve lifter and metal valve lifter are examined and compared into abnormal phenomena such as early fracture unfair and early wear. It is hoped that this research will serve as an important springboard for the future study of heavy duty diesel engine parts developed by ceramics which has a good wear resis-tance relaibility and lightability.

• Journal of the Korean Society of Safety
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• v.1 no.1
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• pp.51-59
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• 1986

This study was conducted to analyse the exact causes of occupational accidents in Korean construction industry and to contribute to the accident prevention programs. The results and conclusions of the field survey are as follows ： 1) The accidents caused by hazardous conditions are 96 percent, and those by unsafe acts are 97.3 percent. The accidents caused simultaneously by two categories are nore than 96 percent. 2) The injured workers who were employed less than 3 months are 71.1 percent. Safety training for newly recruited workers should be required. 3) More than 40 percent of all accidents were occurred in the morning and more than 30 percent were in summer. Required caution should be paid for the time and season. 4) Fracture, cut/laceration/puncture and multiple injuries in the lower extremeties, upper entremeties and head as well as many kinds of injuries by the fall from elevation mainly occurred. Safety. shoes, safety gloves, safety helmets, safety glasses, face shields and safity belts should be used 5) As the sources of injuries, each of building/structure and materials is one third of all sources, and machinery is a quarter. 6) The use of hazardous methods/procedures, defects of agencies and inadequate guarding of builing/structure, materials' and machinery mainly caused the accident types, such as s truck by, struck against, fall from elevation, and fall on same level. Such a hazardous conditiion should not be used and be correctet 7) The unsafe acts, such as improper use of hands or body parts, the operation or working at unsafe speed and improper use of equipment mainly caused accidents. Safety training for the control of such a unsafe acts should be strengthened.

• Tunnel and Underground Space
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• v.11 no.1
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• pp.30-35
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• 2001

Focusing on the bench length, this paper presents the results of 3-dimensional elafto-plastic FE Analysis un tunnels of full face, mini-bench and short bench excavated in weathered rock. Influences of unsupported span, horizontal to vertical stress ratio, thickness of shotcrete on the behavior of rock and support were a1so studied. Results showed that displacements of mini-bench tunnels responded more sensitively to bench lengths than those of short bench. The effects of bench excavation on upper half displacement increased with longer unsupported span. Horizontal to vertical stress ratio showed a greater influence on displacement and preceding displacement ratio or sidewall rather than those of crown and invert.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.7
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• pp.1173-1183
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• 1997

In order to flatter the figures of average middle aged women by determining harmonious proportions for their costume forms, this study evaluates effects of varying design details of jackets(coats) with blouses and slacks using a ranking test and paired comparisons test. The result from clothing design C-2 which has the best design effect were as follows; 1. In order to look taller, the jacket(coats) is divided vertical long line and it has the emphasis point close to the face. 2. In order to make shoulder width look wider, armhole seam line attached 1-2 cm from the shoulder point. 3. In order to make chest width look slimmer, division was made up of a tailored collar with a deep V-neckline. 4. In order to make waist circumference look slimmer, the jacket has more fitted waist line than loosed it and tailored collar with a deep V-neckline. 5. In the case of the division of upper and lower garments, when the division was closer to the golden section, i.e., when the jacket hemline is hipline and slacks length is the heel excluded length of shoe heels, the overall appearance was better. 6. The V-neckline looked better, when it was cut along a long acute angle to the waist line. Because of dividing along above factors 1-6 i.e., clothing design C-2 was overall harmonious. Appropriate division of costume forms made for an aesthetic composition, which flattered the body types of middle aged women and presented harmonious, beautiful costume design effects. It made the women look taller, slim and balanced, and highlighted middle aged women's sense of beauty.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.8
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• pp.1297-1309
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• 2007

The purpose of this study is to investigate the effect of shirt color, tie color, tone, perceiver' gender on impression formation by applying tone-in-tone coloration of shirt and necktie: coloration of two colors. This experiment was designed to utilize the $2{\times}6{\times}4{\times}2$ factorial designs. and they are shirt color(red, blue), tie color(red, yellow red, yellow, green, blue, purple), tone(vivid, light, dull, dark), and perceiver' gender(a male, a female). The experimental materials developed for this study were a set of stimulus and response scales. The stimuli were 48 upper body photographs which were color outputs by CAD system(4D-box program). The subjects of this research were 288 male and 288 female college students. There were established impression dimension from factor analysis 27 bi-polar adjectives and investigated the effect of interaction between each variable affected impression formations. The items of the adjectives are classified into 4 Impression dimensions: activity, potency, attractiveness, and tenderness. Shirt color, tie color, tone, and perceiver' gender influenced on impression formation. Specially, tie color and tone influenced on the 4 impression dimension greatly by interaction as well as independently. As a result tie is very important clue of impression formation in tone-in-tone coloration of shirt and necktie. Even though tie occupies only a small area in men's clothes it has great effect since it is close to the face.

• Korean Journal of Digital Imaging in Medicine
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• v.17 no.1
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• pp.33-41
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• 2015

This study attempts to examine the clinical usefulness of High b-value DWI (diffusion weighted imaging) for brain tumors with an edema. Subjects were seven patients selected from 65 patients who received an MRI scan for suspected encephalopathy and confirmed diagnosis at our hospital from February to July 2015 (male: 7, average age : 66 years old). As test equipment, 3.0T MR System (ACHIEVA Release, Philips, Best, The Netherlands) and 8Channel SENSE Head Coill were used. DWI checks on the use of the variable TR 5460ms, TE 132ms, Slice Thickness 4mm, gap 1mm, Slice number 29 is, 3D T1WI is TR 8.4ms, TE 3.9ms, matrix size $240{\times}240$, Slice can set 180 piecesIt was. b value of 0, 1,000, 2,000 s/mm2 with DWI acquisition and 3D T1WI enhancement five minutes after the Slice Thickness 3mm, gap 0mm to reconstruct the upper face axis (MPR TRA CE) was. As for the experiment, in b-value 1,000 and 2,000 images, SNR and the lesion at the lesion site and CNR in the normal site opposite to the lesion are measured. WW(window width) and WL(window level) are made equal in MRICro software, and the volume of the lesion is measured from each of b-value and MPR TRA CE image. Using SPSS ver. 1.8.0.0 Mann Whitney-test was analyzed for SNR and CNR, while Kruskal-Wallis test was analyzed for volume.

• Archives of Reconstructive Microsurgery
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• v.24 no.1
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• pp.7-12
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• 2015

Purpose: The rectus abdominis musculocutaneous (RAM) flap has contributed to the efficient reconstruction of soft tissue defects. The flap has the advantage of easy dissection, minimal donor site morbidity, and the constant vascular anatomy with long pedicle. Authors used the free RAM flap to reconstruct multi-located soft tissue defects while still considering functionality and aesthetics. We present the long-term outcomes and versatility of free RAM flaps. Materials and Methods: From 1994 to 2004, all patients who underwent soft tissue reconstruction with free RAM flap were reviewed retrospectively. The site of the reconstruction, vessels of anastomosis, type of RAM flap, and outcomes, including flap success rate, hospital stay after flap transfer, conduction of secondary procedure, flap complications, and donor-site complications were analyzed. Results: Twenty-one patients underwent 24 free RAM flaps in site of breast, face, upper extremity and lower extremity. Mean follow-up period was 36.1 months (range, 3~156 months). The overall success rate was 92% with only a loss of 2 flaps. Minor complications related to transferred flaps were necrosis of 2 partial flaps, hematoma formation in 3 cases, and a wound infection in 1 case. Donor site morbidity was not observed. Debulking surgery was performed in 4 patients, and scar revision was performed in 3 patients. Conclusion: Free RAM flap is a workhorse flap for general soft-tissue reconstruction with minimal donor site morbidity with aesthetically good results. Thus, the free RAM flaps are versatile, and sturdy for any sites of soft-tissue where reconstruction could be performed.