A comprehensive sharp-interface simulation-optimization model for fresh and saline groundwater management in coastal areas

Park, Namsik,Shi, Lei Verlag Heinz Heise 2015 Hydrogeology journal Vol.23 No.6

<P> Both fresh and saline groundwater may be of some value to coastal communities. A comprehensive simulation-optimization model was developed to identify optimal solutions for managing both types of groundwater in coastal areas. The model may be used for conventional management problems of fresh groundwater development and of seawater intrusion control. In addition, the model can be used for problems of concurrent development of fresh and saline/brackish groundwater for beneficial uses. A set of hypothetical examples is given to demonstrate the applicability of the proposed model. In the protection of an over-exploiting freshwater pumping well, the saltwater pumping scheme was less efficient than the freshwater injection scheme. Although the former scheme may be more advantageous in some limited cases, the latter should be considered first as it retains more freshwater in the aquifer. The example of the concurrent development of fresh and brackish groundwater exhibited two different sets of optimal solutions: one with a large amount of freshwater and a small amount of brackish water with high salinity, and the other with a small amount of freshwater and a large amount of brackish water with low salinity. </P>

Genetic polymorphism in the pregnancy-associated plasma protein-A associated with acute myocardial infarction

Park, Sungha,Youn, Jong-Chan,Shin, Dong-Jik,Park, Chan-Mi,Kim, Jung-Sun,Ko, Young-Guk,Choi, Donghoon,Ha, Jong-Won,Jang, Yangsoo,Chung, Namsik Lippincott Williams Wilkins, Inc. 2007 Coronary artery disease Vol.18 No.6

BACKGROUND: Pregnancy-associated plasma protein-A (PAPP-A) is a high-molecular-weight, zinc-binding matrix metalloproteinase that is known to be abundantly expressed in ruptured plaques. Previous studies have shown PAPP-A to be a significant marker of plaque instability and cardiovascular events in patients with acute coronary syndromes. Because the activity of PAPP-A may be modulated by genetic variants in the PAPP-A genes, we tried to determine the association of PAPP-A gene with acute myocardial infarction (AMI). METHODS: We analyzed four single nucleotide polymorphisms (SNPs) of PAPP-A gene variants and seven other polymorphisms of cytokine genes that have been reported to have functional significance (RANTES G-403A, MCP1 G-2518A, CRP A2147G, CRP G-717A, AGER G557A, LTA T26A, IL-6 G-572C) for possible association with AMI in 170 unrelated AMI patients and unrelated age-matched controls, respectively. RESULTS: The average age of the study population was 62.2±11.4 years in AMI patients and 62.6±10.4 years in healthy controls. Multiple logistic regression analysis with risk factors such as age, male sex, smoking, hypertension, diabetes mellitus, and dyslipidemia revealed the PAPP-A IVS6+95 C allele to be associated with an increased risk of AMI (dominancy: odds ratio, 2.13; 95% confidence interval, 1.12–4.07; P=0.022; codominancy: odds ratio, 1.89; 95% confidence interval, 1.14–3.16; P=0.015). CONCLUSIONS: We found, for the first time, that PAPP-A IVS6+95 C allele is an independent risk factor for AMI even after adjustment for traditional risk factors. The determination of such genotype contributing to AMI could provide a new tool for identifying high-risk individuals.

Analytical Design Curves to Maximize Pumping or Minimize Injection in Coastal Aquifers

Park, Namsik,Cui, Lei,Shi, Lei Wiley (Blackwell Publishing) 2009 Ground water Vol.47 No.6

<P>Explicit algebraic equations are derived to determine approximate maximum pumping rates or minimum injection rates to limit sea water intrusion to a prespecified distance from the coastline. The equations are based on Strack's (1976) single-potential solution. The maximum pumping rates and minimum injection rates applied at wells with uniform spacing to control the inland movement of the fresh water-salt water interface in a coastal aquifer could be calculated from Strack's (1976) solution without the need of a numerical optimization algorithm. When wells are distributed in a simple fashion, the maximum intrusion location can be identified precisely for pumping cases and approximately for injection cases. For pumping cases, critical points are the limit of allowable salt water intrusion, whereas no such limit exists for injection cases. Once an application site is identified, a series of design curves for pumping and injection rates can be developed for arbitrary intrusion limits. When a user is interested only in the largest pumping rates associated with critical points, one design curve can yield complete information.</P>

대규모 청정 지하 저수지 기술개발에 대하여

박남식(Namsik Park),정은태(Euntae Jung),남병희(Byunghee Nam) 대한토목학회 2016 대한토목학회지 Vol.64 No.3

행동 지향적 예술로서의 인공생명 아트 연구

박남식(Namsik Park),정문열(Moonryul Jung) 한국HCI학회 2009 한국HCI학회 학술대회 Vol.2009 No.2

기술의 발전은 사회에 많은 변화를 일으키고 있다. 또한 기술의 발전은 예술 영역에 있어서도 형식과 내용에 많은 변화와 영향을 주고 있다. 컴퓨터 아트, 인터액티브 아트, 뉴 미디어 아트라고 불리는 새로운 예술 장르들이 탄생하였으며 예술가들은 다양한 기술과 접목하여 새로운 작품을 만들어 내고 있다. 뉴 미디어 아트의 중요한 특징 중 하나는 상호작용성인데 이것은 예술작품, 예술가, 그리고 관람자의 수용방식에 결정적인 변화를 가져왔다. 즉 뉴미디어 아트서의 예술작품은 완성태가 아닌 과정(process)으로 주어지고, 예술가는 작업의 초안자 또는 작업의 맥락을 규정하는 자로 규정되며, 작품과 관람자간의 상호작용이 무엇보다 강조된다. 그러나 기존의 뉴 미디어 작품에서 일어나는 상호작용성은 미리 계산된 범위 안에서 일어나는 제약이 있기에 진정한 상호작용성이라고 보기 힘들다는 비판도 있다. 이런 상호작용성은 공학적 세계관에 갇힌 닫힌 시스템으로서의 상호작용성이라고 말하며 미적인 상호작용성의 도구로서 열린 시스템으로서의 새로운 작품의 필요성을 제시한 예술가들이 있다. 본 논문은 이러한 예술가들의 발자취를 따라 더 본질적인 미학적 상호작용성에 대한 고민과 함께 그에 따른 새로운 상호작용적 예술인 행동지향적 예술로서 인공지능, 인공생명 아트에 대하여 살펴보고자 한다.

Association of RAGE gene polymorphisms with coronary artery disease in the Korean population

Yoon, Se-Jung,Park, Sungha,Shim, Chi Young,Park, Chan Mi,Ko, Young-Guk,Choi, Donghoon,Park, Hyun-Young,Oh, Bermseok,Kim, HungTae,Jang, Yangsoo,Chung, Namsik Lippincott Williams Wilkins, Inc. 2007 Coronary artery disease Vol.18 No.1

BACKGROUND AND OBJECTIVES: AGEs (advanced glycation end products)–RAGE (receptor for advanced glycation end products) interaction in vessel wall may lead to inflammation, smooth muscle cell proliferation and extracellular matrix production, culminating in exaggerated intimal hyperplasia and restenosis. We focused on the putative association of five candidate RAGE gene polymorphisms on the risk of coronary artery disease in the Korean population. METHODS: A total of 1555 male patients who underwent coronary angiography were enrolled in the study; 805 patients (mean age: 53.18±9.74 years) had normal coronary artery and 750 patients (mean age: 55.73±8.31 years) had significant coronary artery disease. Among the coronary artery disease patients, 269 had single-vessel disease (35.87%), 242 had two-vessel disease (32.27%) and 239 had three-vessel disease (31.87%). The genotypes of RAGE were determined by the methods of single base extension with amplifying primers and probes for TaqMan. Genotype analysis was performed on five single nucleotide polymorphisms of the RAGE gene, namely −443T>C, −388T>A, −257G>A, +557G>A and +1704G>T. Analysis for the association with coronary artery disease was performed. RESULTS: Analysis of four single nucleotide polymorphisms, except +557G>A (G82S), with regard to the association with coronary artery disease was not significant. Only the +557 gene allele (G/A) showed significant association with coronary artery disease (coronary artery disease vs. normal; G allele: 0.87 vs. 0.84, A allele: 0.13 vs. 0.16, P=0.0326). The +557G>A (G82S) showed strong tendency of association with coronary artery disease (coronary artery disease vs. normal; GG: 75.2 vs. 69.8%, GA: 23.2 vs. 28.6%, AA: 1.6 vs. 1.6%, P=0.0524). The presence of AA or GA genotype, assuming codominant effect of the A allele, was independently associated with decreased risk of coronary artery disease when controlled for age, body mass index, smoking and diabetes mellitus [odds ratio=0.749 (95% confidence interval, 0.579–0.969), P=0.0280]. Subgroup analysis demonstrated the significant protective effect of AA or GA genotype in nondiabetic patients as well [odds ratio=0.741 (0.570–0.962), P=0.0244]. CONCLUSIONS: The results of this large population study demonstrate that the AA/GA genotypes of the RAGE +557G>A polymorphism are associated with a significantly decreased risk of significant coronary artery disease. Other polymorphisms of RAGE were not significantly associated with the risk of coronary artery disease in this study population.

공기실을 이용한 수격현상 제어에 관한 실험연구

박남식,서헌명 동아대학교 건설기술연구소 1999 硏究報告 Vol.23 No.2

A pipe network model is used to conduct experiments on performance of an air vessel, which is used to control waterhammer phenomena. The network model consists of total length of 336m of 50mm-diameter PVC pipe and a data acquisition and control system. The height and the diameter of the stainless-steel air vessel are 1.2m and 0.9m, respectively. The performance is investigated using pressure data measured at four locations: inlet water pressure, air-vessel water pressure, air-vessel air pressure, and outlet pressure. Pressure transducers of the range 0-7bar are used. Preliminary experiments indicate that the pressure damping effects of the air vessel is over 75%.

The influence of serum aldosterone and the aldosterone–renin ratio on pulse wave velocity in hypertensive patients

Park, Sungha,Kim, Jin-Bae,Shim, Chi Young,Ko, Young-Guk,Choi, Donghoon,Jang, Yangsoo,Chung, Namsik Lippincott Williams Wilkins, Inc. 2007 Journal of Hypertension Vol.25 No.6

OBJECTIVE: The aldosterone–renin ratio (ARR) is widely used to screen for primary aldosteronism, and may reflect a relative excess of aldosterone secretion compared with renin secretion. Excess aldosterone may have a detrimental effect on vascular stiffness. We therefore hypothesized that ARR and aldosterone are independently correlated with pulse wave velocity (PWV) in hypertensive patients. METHODS: The study consisted of 438 hypertensive patients. Serum aldosterone and plasma renin activity were measured in a sitting position using standard techniques. The PWV was determined by measuring the heart to femoral PWV (hfPWV) and brachial to ankle PWV with a VP-2000 pulse wave unit. RESULTS: Group 1 was defined as patients with ARR of at least 20 (n = 53) with serum aldosterone ≥ 12 ng/dl, while the remainder comprised group 2. Comparisons between the two groups reveal group 1 tended to have higher age, significantly higher proportion of women and higher systolic/diastolic blood pressure. Patients in group 1 also had a significantly higher index of central arterial stiffness (hfPWV 1048 ± 202 vs 978 ± 182, P = 0.010) compared with group 2. Multiple linear regression revealed that aldosterone, but not the ARR, is significantly associated with hfPWV but not brachial to ankle PWV, after controlling for age, systolic blood pressure and heart rate at the time of PWV measurement, body mass index, gender, low-density lipoprotein-cholesterol, triglyceride, high-density lipoprotein-cholesterol, blood pressure medication and statins. CONCLUSIONS: Serum aldosterone is significantly associated with central aortic PWV in hypertensive patients. The results demonstrate a possible role for aldosterone in developing central aortic stiffness and increased PWV in hypertensive patients.

Gender-Related Difference in Arterial Elastance During Exercise in Patients With Hypertension

Park, Sungha,Ha, Jong-Won,Shim, Chi Young,Choi, Eui-Young,Kim, Jin-Mi,Ahn, Jeong-Ah,Lee, Se-Wha,Rim, Se-Joong,Chung, Namsik Ovid Technologies Wolters Kluwer -American Heart A 2008 Hypertension Vol.51 No.4

<P>Exercise intolerance and heart failure with preserved ejection fraction are common in females. Recently, arterial stiffness has been suggested to be a significant contributor in the development of heart failure. How gender difference affects arterial stiffening and its response to exercise is not well known. We hypothesized that arterial elastance index during exercise would be more abnormal in females with hypertension than males. Arterial elastance index was estimated as arterial end systolic pressure/stroke volume controlled for body surface area and was measured at rest and during graded supine bicycle exercise (25 watts, 3-minute increments) in 298 patients with hypertension (149 males; 149 females; mean age, 59). The subjects were divided into 2 groups by gender. Exercise duration was significantly shorter in females compared to males (692+/-222 versus 483+/-128 seconds, P<0.001). Although arterial elastance index at baseline was significantly higher in males, the magnitude of increase was steeper in females with the magnitude of change at 75 W of exercise being significantly higher in females compared to males (0.69+/-0.83 versus 0.43+/-0.69, P=0.018). Arterial elastance index at each stage of exercise up to 75 W was independently associated with decreased exercise duration. In conclusion, despite lower arterial elastance index at rest, the increase during exercise was steeper in women with hypertension, suggesting a gender-related difference in dynamic arterial stiffness. The arterial elastance index during exercise was significantly associated with exercise duration in patients with hypertension.</P>

귀농어·귀촌 인식 및 관련 교육 실태에 관한 연구 : 퇴직 예정 서울특별시 지방공무원을 대상으로

박성택(Park, Sungtaek),이태겸(Lee, Taegyeom),정남식(Jung, Namsik) 경기연구원 2020 GRI 연구논총 Vol.22 No.4