• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.751-756
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• 2001

An experimental model of the advanced mixing control in the parallel supersonic-subsonic mixing jet (M$_1$=1.78 and M$_2$=0.30) is numerically simulated. An oscillating wall boundary condition is used as the modeling of a wall cavity for mixing enhancement. The obtained pitot pressure distributions along cross sections at the developing region of the turbulent jets are validated from the good agreement with equivalent experimental data. The similarity solution of dimensional analysis also coincides with this numerical result at the self-similar region sufficiently far from the jet exit.

• 소음진동
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• 제8권5호
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• pp.849-855
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• 1998

An analysis of lateral hydrodynamic forces of compressor labyrinth seals is presented. Basic equations are derived using a two-control-volume model for compressible flow. Blasius' wall friction-factor formula and jet flow theory are used for the calculaton of wall shear stresses and recirculation velocity in the cavity. Linearized zeroth-order and first-order perturbation equations are developed for a small motion about the centered position by expansion in the eccentricity ratio. Integraton of the resultant first-order pressure distribution over the seal defines the rotordynamic coefficients. As an application a rotordynamic analysis of the balance drum labyrinth seal found in an ethylene regrigeration copmressor is carried out. The rotordynamic characteristic results of the labyrinth seal are presented and compared with other types of seals, honeycomb seal and smooth seal.

• 한국주조공학회지
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• 제28권4호
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• pp.190-194
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• 2008

Thin-walled die casting of aluminum notebook computer housing with less than 1mm thickness was investigated by using computational solidification simulation and actual casting experiment. Three different types of gate design, finger, tangential and split type, were used and the results showed that sound thin-walled die casting was possible with tangential and split type gating design because those gates allowed aluminum melt flowed into the thin-wall cavity uniformly and split type gating system was preferable gating design than tangential type at the point of view of soundness of casting and distortion generated after solidification. Also, solidification simulation agreed well with the actual die-casting and the casting showed no casting defect and distortion.

• 한국동물위생학회지
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• 제21권4호
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• pp.407-411
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• 1998

Aspergillosis, caused by infection with Aspergillus fumigatus and less commonly by other Aspergillus species, is a prevalent and costly respiratory disease of poultry, In a flock of chicks, the number of birds, 4∼5 months old, had become gradually emaciated and subsequently died. Gross necropsy revealed multiple granulomatous masses on the abdominal serosa. The masses, 4∼15 mm in size, were attached on mainly intestinal wall. Also, the smaller masses in size were on mesentery and pancreas. However, only a few small white nodules were scattered throughout liver and lung in few samples. Microscopically, the mass were granulomatous with a central area of necrosis containing numerous septate, branched fungal hypae consistent with Aspergillus sp. These were surrounded by macrophages, giant cells, lymphocytes and fibrous tissues. Nodular lesions of liver and lung were seemed to spread hemotogenously from intestine and the possible route of infection was speculated by oral. This report is a Aspergillus-induced granuloma limited to the serosa of abdominal cavity, especially of intestinal wall.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.149-153
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• 2008

The cavity of mold is exposed to high pressure during injection molding operation. Injection molded articles with deep depth are often demanded as design variety increases. Mold becomes weak and deformation increases as the mold depth increases. Thus the injection molds for deep depth articles should be designed to hold out high pressure or stress and large deformation. Through this study, equation for mold design was examined and suggested novel method to determine equation for mold design with deep depth. Novel equation developed in this study was consisted with cantilever and two points bending while previous equation was modified from just cantilever bending. The validity of novel equation was verified through computer simulation.

• 한국임상수의학회지
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• 제14권2호
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• pp.352-356
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• 1997

5 years Poodle was referred to the Veterinary Teaching Hospital, Chonnam National University in January 1997, with progressive swelling on the rear xiphoid process after cesarean section last year in local-vet clinic. Physical, radiographic, ultrasonographic and intraoperative findings that were obtained from this case were as follow; Physical findings were known as no pain, no fever in the hernia] sal at palpation. Radiographic findings revealed the decreased density of swelling contents more than peritoneum and did not identify the abdominal wall defect line. Ultrasonographic findings showed abdominal wall defect line of 3mm and intra-abdominal originated fat contents with mixed echo(hypoechoic). During the operation, falciform ligament into the hernial sac was observed and not excised, manipulated back into the cavity. The dog was given an herniorraphy with no recurrence and infection.

• Journal of Chest Surgery
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• 제3권2호
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• pp.113-120
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• 1970

Since the turn of the century there has been a constant search for a satisfactory method of controlling a large intrathoracic space following lobectomy. Primarily these methods consist of thoracoplasty, plombage, and phrenic nerve paralysis which are not completely satisfactory for they may result in loss of chest wall motility or diaphragmatic function. Incising the diaphragm at its periphery and resuturing to the chest wall at a level several rib spaces higher is an effective method of reducing intrathoracic space with minimal interference with pulmonary function. It is of particular value when the anticipated space problem is in the lower part of the thoracic cavity. Five cases are presented in which the diaphragm was peripherally detached and advanced to higher levels. Two cases were following lower lobectomy and three cases were following decortication for chronic empyema in which expansion was not good enough to adequately fill the space. Results in these cases were satisfactory.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.301-304
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• 2008

The cavity of mold is exposed to high pressure during injection molding operation. Injection molded articles with deep depth are often demanded as design variety increases. Mold becomes weak and deformation increases as the mold depth increases. Thus the injection molds for deep depth articles should be designed to hold out high pressure or stress and large deformation. Through this study, equation for mold design was examined and suggested novel method to determine equation for mold design with deep depth. Novel equation developed in this study was consisted with cantilever and two points bending while previous equation was modified from just cantilever bending. The validity of novel equation was verified through computer simulation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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• pp.138-144
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• 1997

The analysis of lateral hydrodynamic forces from the compressor labyrinth seals is presented. The basic equations are derived using a two-control-volume model for compressible flow. Blasius' wall friction-factor formula and jet flow theory are used for the calculation of the wall shear stresses and the recirculation velocity in the cavity. Linearized zeroth-order and first-order perturbation equations are developed for small motion about a centered position by an expansion in the eccentricity ratio. Integration of the resultant first-order pressure distribution along and around the seal defines the rotordynamic coefficients of the labyrinth seal. The rotordynamic analysis for the balance drum labyrinth seal of an ethylene refrigeration compressor is carried out. The results of rotordynamic characteristic of the labyrinth seal and comparisons with other types of seal, honeycomb seal and smooth seal, are presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.457-460
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• 2004

This study examines the sound insulation of the light-weight wall using light-weight concrete and offers the basic datum for enhancing it. The sound insulation of the light-weight wall is determinated by the density, installation method, absorption materials, air layers etc. Among the factors, the solution of outlet that is the major cause of reducing sound insulation should be made. If absorption materials are installed in the cavity walls, it enhances to 15dB in 500Hz.