• Journal of the Korean Society for Precision Engineering
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• v.19 no.3
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• pp.131-136
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• 2002

A design system of dies for hot extrusion of structural shapes such as Z's, L's, T's, U's and H's from aluminium alloys was developed in this study. The developed design system of dies is based of estimated die design rule system. The design rules for die design are obtained from the handbooks, plasticity theories and relevant references. The environment of the system is AutoCAD and AutoLISP, the graphic programming language was used for the configuration of the system. This system includes five major modules such as section shape design module, die opening number module, die opening layout module, die correction module and die bearing design module that are used to determine design variables. This system would be used to design of dies for hot extrusion from aluminum alloys and widely used in manufacturing course.

• Transactions of Materials Processing
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• v.14 no.3 s.75
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• pp.245-250
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• 2005

Recently, micro machining technology for high precision mold becomes more interested for mass production of high performance optical parts micro-grooved on the surface, which is under very active development due to its effectiveness in the view point of optical performance. Mechanical micro machining technology now has more competitiveness on lithography, MEMS or LIGA processes which have some problems to fabricate especially cylinder type of groove in such as lenticular lens for illumination angle modulation system. In this study. a lenticular lens mold with U-type micro groove is fabricated making utilizing of the benefit of the mechanical micro machining technology. A shaping machining process is adapted using 3 axis degree of freedom micro machining system and single crystal natural diamond tool. A brass and a electroless nickel materials are used for mold fabrication. Machining force, chip shape and machined surface are investigated from the experiment and an optimal machining condition is found based on the examined problems from the micro cutting process.

• Korean Journal of Applied Biomechanics
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• v.23 no.4
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• pp.319-326
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• 2013

The objective of this study is to help golfers to select adequate putters and to provide golfers basic scientific data for improving athletic performance by showing differences of kinematic variables according to the shape of putter head. In this research three right-handed male pro-golfer who are listed at KPGA were studied and three video camera (GR-HD1KR, JVC, Japan) were used and recording speed was 60 frame/sec during the research. In this study kinematic variables were calculated using Kwon3D XP program and analysed on the 4 events and 3 phases. This study showed the following results : (1) The swing of heel-toe putter showed longer time than that of face balanced putter, and there are statistical significant difference of kinematic variables of each objective (2) As of the trajectory of putter head, heel-toe putter showed more approximating curve trajectory than that of in-between, face balanced putter on the X-axis (3) heel-toe putter showed longer distance follow-through than that of other putters by statistically significant difference on the Y-axis (4) Heel-toe putter showed longer distance swing trajectory over the ground than that of other putters by statistically significant difference on the Z-axis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.35.1-35.7
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• 2015

After cleft lip repair, many patients suffer from nasolabial fistulas, asymmetrical nasal floor, or an indistinct nostril sill, as well as intraoral wound dehiscence and subsequent scar contracture of surgical wounds leading to vestibular stenosis. For successful primary nasolabial repair of complete cleft deformity of the primary palate, cleft surgeons need special care in reconstructing the sound nasal floor. Especially when the cleft gap is wide or when any type of nasoalveolar molding therapy was not performed, three-dimensional reconstruction of the nasal floor is critical for a balanced nasal shape. In this study, the author describes an effective method for reconstructing a double-layered nasal floor using two mucosal flaps from both sides of the fissured upper lip. This is a report of six patients with unilateral or bilateral complete cleft of the primary palate with a detailed description of the surgical technique and a literature review.

• Journal of Species Research
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• v.4 no.1
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• pp.49-56
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• 2015

Zeuzera is one of the most important wood borer pests in South East Asia. Like of most other genera of moths, the systematic of this genus is still in dispute, especially on the monophyly and the relationship within this genus due to the fact that genus is very varied. This genus was defined based on external characters only such as cross vein Sc-Rs present, humeral plate approximately triangular in shape and anal plate moderately long to moderately short. Therefore, the monophyly of this genus need to be evaluated based on more comprehensive data. To clarify the monophyly of the genus Zeuzera, to reveal the phylogenetic relationships among the Indonesian species, and to establish the genetic characters of Indonesian Zeuzera, we analyzed seven species of Indonesian Zeuzera including three other species distributed around the world based on nucleotide sequence variation across a 580-bp region in the CO I gene. The results showed that the monophyly of Zeuzera was supported by bootstrap tests at the MP and ML tree building methods (>95%). Genus Zeuzera was divided into two groups (A and B) with Z. borneana was excluded from the two groups and occupied at the basal node. Indonesian species was distributed into two different clades. CO I gene alone was able to fully resolve the relationships among species within clade B. However, further investigations were needed by including more species and other genes that the more conserved to test the validity of the phylogenetic hypothesis proposed here.

• Journal of Distribution Science
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• v.18 no.7
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• pp.37-48
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• 2020

Purpose: There has been an increasing focus on consumer ethics by researchers and practitioners alike with the former seeking to examine the general discrepancy between ethical attitude, intention and actual behaviour by proposing behavioural measures to understand ethical consumption. Research into the effects of generational cohorts and gender, two fundamental demographic factors that shape the consumer habituated repertoire, on consumer ethics has reported mixed findings. The present study investigates if there are differences in ethical consumer behavior by generational cohorts and by gender in the context of an emerging market - Vietnam. Research design, data and methodology: Data was collected using a quantitative survey (a link to the questionnaire was posted on relevant social media platforms). A total of 539 usable responses was used for ANOVAs and independent t-tests to test the hypotheses. Results: a) There are significant differences in terms of ethical consumer behavior between Gen Z and Gens Y/X, but no difference between Gen X and Gen Y; b) There is no gender difference in ethically minded consumer behavior. Conclusion: For consumer ethics, generational effects may be moderated by macroeconomic conditions, while gender alone as a biological variable may not be a reliable predictor.

• The Journal of Korean Physical Therapy
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• v.14 no.3
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• pp.373-406
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• 2002

This study was peformed to investigate the effects on skeletal muscle recovery with aqua-exercise; swimming to take the muscle endurance for 20 days on two group of white rats which were the low extremity atrophy group(control groups) by fixed for two weeks and aqua-exercise group(experimental groups) after it. The effects was observed with light and electron microcope to measure the morphological changes of muscle fibers. The results obtained were as follow. 1. Light microscope: In the case of control groups, quadriceps fibers had been irregular alignment, decreased muscle width and the irregular alignment nuclear appeared, as it is degenerative muscle fibers. In the case of experimental groups, the fibers had been regular alignment cells and fibers. The nucleus of muscle had been normal characterized by oval shape and fiber sarcomere clearly classified. 2. Electron microscope: In the case of control groups, there were the quadriceps which was Z-line streaming phenomenon induced at the sarcomere and cells nuclear separated from basal membrane. It was not only observed the sarcomere alignment irregularly and mitochondria damaged, but also vacuoles found. In the case of experimental groups, A band, I band, H band had been clearly appeared, classified at the myofibrils of quadriceps, and electronic dense M-line found in sarcomere. There were observed satellite cells and basal laminas that usually to be appeared at the time of mitochondrial development, skeletal muscle fiber regeneration or development. This results suggest that the aqua-exercise assisted to inhibit the degenerative morphological changes of skeletal muscle cells and help to recover from abnormal states. Especially, it is considered to effect on a normal structural formation.

• Archives of Plastic Surgery
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• v.32 no.1
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• pp.110-116
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• 2005

Male pseudohermaphroditism is individuals with Y chromosome whose external appearances fail to develop as expected as a normal male. Cytogenetic form of male pseudohermaphroditism was 46XY but external genital forms were variable. We reviewed data from 7 patients with male pseudohermaphroditism operated in Dong-A University Hospital from January 1996 to August 2002. They all had severe form of hypospadias (pseudovaginal perineoscrotal type). Only 1 of 7 cases was operated urethroplasty by one stage method, and all others by two stage method. Patients with mild chordee were operated by one stage method and patients with severe chordee were operated by two stage method. Complete chordee release was done by Z-plasty or FTSG on the first stage and posterior urethroplasty was done at level of mid-dorsum of shaft at the same time. Anterior urethroplasty was done completely on the second stage. Results were good from the viewpoint of shape and urination. Urethral fistula occurred in two cases, but other complications (infection, urethral stricture, etc.) didn't occur. In conclusion, two stage method was compatible to correct hypospadias in male pseudohermaphroditism, because hypospadias in male pseudohermaphroditism is in severe form.

• Structural Engineering and Mechanics
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• v.66 no.2
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• pp.161-172
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• 2018

The passive control of structures using a pendulum tuned mass damper has been extensively studied in the technical literature. As the frequency of the pendulum depends only on its length and the acceleration of gravity, to tune the frequency of the pendulum with that of the structure, the pendulum length is the only design variable. However, in many cases, the required length and the space necessary for its installation are not compatible with the design. In these cases, one can replace the classical pendulum by a virtual pendulum which consists of a mass moving over a curved surface, allowing thus for a greater flexibility in the absorber design, since the length of the pendulum becomes irrelevant and the shape of the curved surface can be optimized. A mathematical model for a building with a pendular tuned mass damper and a detailed parametric analysis is conducted to study the influence of this device on the nonlinear oscillations and stability of the main system under harmonic and seismic base excitation. In addition to the circular profiles, different curved surfaces with softening and hardening characteristics are analyzed. Also, the influence of impact on energy dissipation is considered. A detailed parametric analysis is presented showing that the proposed damper can not only reduce sharply the displacements, and consequently the internal forces in the main structure, but also the accelerations, increasing user comfort. A review of the relevant aspects is also presented.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.174-179
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• 2005

In the super slow speed die casting process, the casting defects due to melt flow should be controlled in order to obtain sound casting products. The casting defects that are caused by molten metal were cold shut formation, entrapment of air, gas, and inclusion. But the control of casting defects has been based on the experience of the foundry engineers. The calculation of simulation can produce very useful and important results. The calculation data of die casting process condition from the computer simulation by the Z-CAST is made to insure that the liquid metal is injected at the right velocity range and that the filling time is small enough to prevent premature solidification. The parameters of runner shape that affected on the optimized conditions that was calculated with simple equation were investigated. These die casting process control techniques of automobile valve body mid-plate have achieved good agreement with the experimental data of tensile strength, hardness test, and material structure photographies satisfactory results.