벽면 온도가 선형적으로 증가하는 오발 덕트내의 유동 및 열전달 해석 ( Analysis of Flow and Heat Transfer in Oval Ducts with Linearly Increasing Wall Temperature )

고형종 대한기계학회 1992 대한기계학회 춘추학술대회 Vol.- No.-

오옥신 처리가 탱탱이나무 삽목 발근에 미치는 영향

고형종,소인섭,강훈 제주대학교 아열대농업생명과학연구소 2011 아열대농업생명과학연구지 Vol.27 No.1

오벌 덕트 내의 층류 강제 대류

고형종 金烏工科大學校 1997 論文集 Vol.18 No.-

A laminar forced convection in the oval ducts with peripherally uniform wall temperature is numerically studied. The wall temperature either varies linearly (constant-heat-rate case) or remains uniform (constant-wall-temperature case) along the axial direction. The flow is assumed to have developed thermally as well as hydrodynamically. The equations of the conservation of momentum and energy are discretized by using the control volume method, and solved by means of line successive over-relaxation. The friction factor and the Nusselt numbers are in good agreement with the known results. The plots of isovels and isothermal lines are also presented for some typical cases.

Slit 近傍의 Stokeslet 에 의한 2次元의 느린 粘性流動

고형종,김문언 대한기계학회 1983 대한기계학회논문집 Vol.7 No.4

Two-dimensional slow viscous flow due to a stokeslet near a slit is investigated on the basis of Stokes approximation. Velocity fields and stream function are obtained in closed forms by finding two sectionally holomorphic functions which are determined by reducing the problem to Riemann-Hilbert problems. The force exerted on a small cylinder is calculated for the arbitrary position of the cylinder translating in an arbitrary direction. The features of fluid flow are also investigated.

PINK1 and Parkin to control mitochondria remodeling

고형종,정종경 대한해부학회 2010 Anatomy & Cell Biology Vol.43 No.3

Parkinson’s disease (PD), one of the most common neurodegenerative diseases, is characterized by movement disorders and a loss of dopaminergic (DA) neurons. PD mainly occurs sporadically, but may also result from genetic mutations in several PD-linked genes. Recently, genetic studies with Drosophila mutants, parkin and PINK1, two common PD-associated genes, demonstrated that Parkin acts downstream of PINK1 in maintaining mitochondrial function and integrity. Further studies revealed that PINK1 translocates Parkin to mitochondria and regulates critical mitochondrial remodeling processes. These findings, which suggest that mitochondrial dysfunction is a prominent cause of PD pathogenesis, provide valuable insights which may aid in the development of effective treatments for PD.

PINK1 as a Molecular Checkpoint in the Maintenance of Mitochondrial Function and Integrity

고형종,정종경 한국분자세포생물학회 2012 Molecules and cells Vol.34 No.1

Parkinson’s disease (PD), the most prevalent neurodegenerative movement disorder, is characterized by an age-dependent selective loss of dopaminergic (DA) neurons. Although most PD cases are sporadic, more than 20 responsible genes in familial cases were identified recently. Genetic studies using Drosophila models demonstrate that PINK1, a mitochondrial kinase encoded by a PD-linked gene PINK1, is critical for maintaining mitochondrial function and integrity. This suggests that mitochondrial dysfunction is the main cause of PD pathogenesis. Further genetic and cell biological studies revealed that PINK1 recruits Parkin, an E3 ubiquitin ligase encoded by another PD-linked gene parkin, to mitochondria and regulates the mitochondrial remodeling process via the Parkin-mediated ubiquitination of various mitochondrial proteins. PINK1 also directly phosphorylates the mitochondrial proteins Miro and TRAP1, subsequently inhibiting mitochondrial transport and mitochondrial oxidative damage, respectively. Moreover, recent Drosophila genetic analyses demonstrate that the neuroprotective molecules Sir2 and FOXO specifically complement mito-chondrial dysfunction and DA neuron loss in PINK1 null mutants, suggesting that Sir2 and FOXO protect mitochondria and DA neurons downstream of PINK1. Collectively, these recent results suggest that PINK1 plays multiple roles in mitochondrial quality control by regulating its mitochondrial, cytosolic, and nuclear targets.

환형 오벌 덕트 내의 완전히 발달된 유동에 대한 수치해석

김진태,고형종 國立金烏工科大學校附設生産技術硏究所 1995 産業技術開發硏究 Vol.11 No.-

The fully developed laminar flow in oval annular ducts is numerically analyzed. The discretized flow equation is obained on the basis of finite control volume method, and solved by using the line successive over-relaxation(LSOR) method. The friction factor is calculated for varying values of radius ratio(α) and aspect ratio(β). The product of the friction factor and the Reynolds number lies between two limiting values of 16 and 24, which correspond to the circular duct and the two-dimensional channel respectively. The plot of isovelocity contours are also presented for some typical cases.

Fontan Procedure이후 심장혈관계의 혈류역학적 특성에 관한 수치적 연구

고형종,김경훈,심은보 金烏工科大學校 1998 論文集 Vol.19 No.-

The aim of this study is to develop a computational model representative of the circulation in patients with a uni-ventricular heart sugically palliated by a total atrio-pulmonary connection. A model of the cardiovascular system is built using standard Iumped components such as resistance, voltage source, check valve and capacitor. We assume that there is only an atrium in the right heart part of the model after the Fontan procedure. In this study, baroreceptor reflex and cardiopulmonary reflex control model are implemented to explain the autoregulation of cardiovasculasr system. Another important aspect of the model is to utilize a beat-to-beat approach in sensing pressure deviations, in transferring these to autonomous nerve system, and in regulating the control variables such as heart rate, heart contractility, peripheral resistance, and venous tone. To verify the present code. we have computed the LBNP(Lower Body Negative Pressure)simulation and compared its results with the existing experimental data. The hemodynamic changes after the Fontan procedure are simulated and compared with the existion clinical data. After Fontan procedure, heart rate, CVP(Central venous pressure) and diastolic pressure increase whereas pulse pressure and systolic pressure go down. Increased CVP, induced by the removal of right ventricle, makes the heart rate go up via baroreceptor reflex control. The effects of known hazardous exposures after Fontan procedure are also investigated. We assume increased peripheral resistance to simulate the situation of exposure to cold. In this case increased arterial pressure induces the decrease of heart rate. which results in decrease of cardiac output. On the other hand, exposure to heat increases heart rate and cardiac output. Hemorrhage in cardiovascular system results in increase of ABP(Arterial Blood Pressure) and decrease of heart rate and cardiac output.

환형 오벌 덕트 내의 층류 강제 대류

고형종,김진태 金烏工科大學校 1996 論文集 Vol.17 No.-

The hydrodynamically and thermally fully developed laminar forced convection in oval annular ducts is numerically investigated. For the temperature field, both the constant- wall- temperature case(first kind) and the constant- heat- flux case(second kind) are dealt with. The momentum equation and the energy equation are discretized by using the control volume method. The friction factor and the Nusselt number are calculated for the varying values of radius ratio and aspect ratio. The results for the limiting cases are in good agreement with the known results. The plots of isovels and isothermal lines are also presented for some typical cases.

틈새가 있는 벽면 위를 지나는 2차원 전단류

고형종,정재택 國立金烏工科大學校附設生産技術硏究所 1994 産業技術開發硏究 Vol.10 No.-

Two-dimensional shear flow over a plane wall with a slit is investigated on the basis of Stokes approximation. The flow fields are obtained in a closed form by finding two complex analytic functions which are determined by solving a pair of Riemann-Hilbert problems. The stress distributions on the plate, and the streamline pattern including the local behavior near the sharp edges are calculated. The features of flow are also discussed for the cases where a stagnation point flow or a flow due to pressure difference is superposed to the shear flow.