Effects of intermittent media replacement on the gene expression of differentiating neural progenitor cells

Kim, Hye Young,Kim, Min Jung,Yang, Jung Eun,Kim, Bo Kyung,Han, Jinil,Lee, Yong Sung,Kim, Jin Hyuk The Royal Society of Chemistry 2012 Molecular bioSystems Vol.8 No.2

<P>A culture medium provides the major environmental conditions for cells <I>in vitro.</I> Replenishment of a culture medium causes an abrupt change in the extracellular environment for maintaining cells in a certain state. As a primitive form of a complex system, a stem cell is likely to be influenced by culture conditions that can change the destination of development. To understand how the change in extracellular environment can influence a biological system, we studied the effect of culture media replacement on the gene expression of differentiating neural progenitor cells. From time-series microarray gene expression data of neural progenitor cells, we observed a periodic wave that was synchronized with intermittent culture media replacement. We identified three modes that mostly contribute to the periodic patterns in gene expression and investigated mode-related genes that are sensitive to the changes in the extracellular environment. The biological significance of the three modes was explored, such as progressive development and cell fate decision, extracellular matrix reassembly, and cell growth regulation in response to stress. In addition, we explored systemic influences of media replacement on differentiating neural progenitor cells. Intermittent culture media replacement interrupts expression of genes that participate in the major processes of differentiating neural progenitor cells. This study shows how the abrupt changes in the cell environment influence gene expression systematically.</P> <P>Graphic Abstract</P><P>We identified three modes in genome activity and investigated mode-related genes that are influenced by periodic perturbations in the extracellular environment. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1mb05284e'> </P>

Aseptic Humeral Nonunion: What Went Wrong? What to Do? A Retrospective Analysis of 20 Cases

( Jinil Kim ),( Jae-woo Cho ),( Won-tae Cho ),( Jun-min Cho ),( Namryeol Kim ),( Hak Jun Kim ),( Jong-keon Oh ),( Jin-kak Kim ) 대한외상학회 2016 大韓外傷學會誌 Vol.29 No.4

Purpose: Due to recent advances in internal fixation techniques, instrumentation and orthopedic implants there is an increasing number of humeral shaft fracture treated operatively. As a consequence, an increased number nonunion after operative fixation are being referred to our center. The aim of this study is to report the common error during osteosynthesis that may have led to nonunion and present a systematic analytical approach for the management of aseptic humeral shaft nonunion. Methods: In between January 2007 to December 2013, 20 patients with humeral shaft nonunion after operative procedure were treated according to our treatment algorithm. We could analysis x-rays of 12 patients from initial treatment to nonunion. In a subgroup of 12 patients the initial operative procedure were analyzed to determine the error that may have caused nonunion. The following questions were used to examine the cases: 1) Was the fracture biology preserved during the procedure? 2) Does the implant construct have enough stability to allow fracture healing? Results: In 19 out of 20 patients have showed radiographic evidence of union on follow up. One patient has to undergo reoperation because of the technical error with bone graft placement but eventually healed. There were 2 cases wherein the treatment algorithm was not followed. All patients had problems with mechanical stability, and in 13 patients had biologic problems. In the analysis of the initial operative fixation, only one of 12 patients had biologic problems. Conclusion: In our analysis, the common preventable error made during operative fixation of humeral shaft fracture is failure to provide adequate stability for bony union to occur. And with these cases we have demonstrated a systematic analytic management approach that may be used to prevent surgeons from reproducing the same fault and reduce the need for bone grafting. [ J Trauma Inj 2016; 29: 129-138 ]

그래프 탐색 기법을 이용한 효율적인 웹 크롤링 방법들

김진일(Jinil Kim),권유진(YooJin Kwon),김진욱(Jin Wook Kim),김성렬(Sung-Ryul Kim),박근수(Kunsoo Park) 한국정보과학회 2010 정보과학회논문지 : 시스템 및 이론 Vol.37 No.1

웹 크롤러는 웹에서 링크를 따라다니며 웹 페이지들을 자동으로 다운로드하는 프로그램으로 주로 웹 환경을 연구하거나 검색 엔진을 만들기 위해 사용된다. 기존의 연구들에서는 웹 크롤러가 인기있는 웹 페이지들을 먼저 크롤링 할 수 있도록 몇 가지 방법들이 제안되었으나 그래프 이론 분야에서 연구되어 온 몇몇 그래프 탐색 기법들은 아직 웹 크롤링 방법으로 고려되지 않았다. 이 논문에서는 잘 알려진 너비 우선 탐색, 깊이 우선 탐색 뿐 아니라 사전식 너비 우선 탐색, 사전식 깊이 우선 탐색 및 최대 크기 탐색을 웹 크롤링 방법으로 고려하여 이 중에서 선형적인 시간복잡도를 가지면서도 인기 있는 웹 페이지를 효율적으로 수집할 수 있는 웹 크롤링 방법을 찾는다. 특히 선형 구현이 단순하지 않은 최대 크기 탐색과 사전식 너비 우선 탐색에 대해서는 분할 정제 방법을 이용한 선형 시간 웹 크롤링 방법을 제시한다. 실험 결과는 최대 크기 탐색이 다른 그래프 탐색 방법에 비해 시간 복잡도 및 크롤링 된 페이지들의 질에 있어서 바람직한 성질을 가짐을 보여준다. Web crawlers are fundamental programs which iteratively download web pages by following links of web pages starting from a small set of initial URLs. Previously several web crawling orderings have been proposed to crawl popular web pages in preference to other pages, but some graph search techniques whose characteristics and efficient implementations had been studied in graph theory community have not been applied yet for web crawling orderings. In this paper we consider various graph search techniques including lexicographic breadth-first search, lexicographic depth-first search and maximum cardinality search as well as well-known breadth-first search and depth-first search, and then choose effective web crawling orderings which have linear time complexity and crawl popular pages early. Especially, for maximum cardinality search and lexicographic breadth-first search whose implementations are non-trivial, we propose linear-time web crawling orderings by applying the partition refinement method. Experimental results show that maximum cardinality search has desirable properties in both time complexity and the quality of crawled pages.

한국은행의 역할과 정책수단: 금융안정정책을 중심으로

김인준 ( In June Kim ),김성현 ( Sunghyun Kim ),김소영 ( Soyoung Kim ),김진일 ( Jinill Kim ),신관호 ( Kwanho Shin ) 한국금융연구원 2017 韓國經濟의 分析 Vol.23 No.1

글로벌 금융위기 이후 전 세계적으로 나타나고 있는 저성장, 저물가, 금융불안의 시대를 맞아 기존의 물가안정이나 고용안정 외에 금융안정화가 중앙은행의 중요 목표로 인식되고 있다. 본 연구는 금융안정화를 위해 한국은행이 맡아야 하는 바람직한 역할이 무엇이며 중장기적으로 한국은행이 금융안정화를 위한 거시건전성 정책을 펼치는 데 있어 어떠한 변화가 필요한지에 대해 분석하였다. 본 연구는 한국은행이 신축적 물가상승률 목표제를 그대로 유지하면서 단기적으로 실물경기안정을 동시에 추구하기를 권고한다. 동시에 동 운영체제만으로 한국은행의 새로운 목표인 금융안정을 달성하기는 현실적으로 어렵다고 판단한다. 이번 글로벌 금융위기를 통해 얻은 교훈 중 하나는 전통적으로 가장 중요하게 여겨졌던 두 부문의 안정화, 즉 실물경기의 안정화와 물가의 안정화가 동시에 달성되더라도 금융부문의 불안정성이 커질 수 있고, 결국 금융불안이 증폭되면 일시에 실물과 물가도 불안정해질 수 있다는 사실이다. 따라서 금융불안이 너무 커지기 전에 사전적으로 이에 대응할 필요가 있다. 하지만 통화정책만으로 물가 및 실물 안정을 추구하면서 금융안정까지 추구하는 것에는 상당한 어려움이 따른다. 틴버겐의 법칙에 따르면 여러 목표를 달성하기 위해선 동일한 수의 수단이 필요하다. 경제전체의 금융불안에 사전적으로 대응할 수 있는 수단을 거시건전성 정책수단이라고 한다. 글로벌 금융위기 이후 2011년 새롭게 개정된 한은법에는 금융안정이 한국은행의 새로운 목표로 명시되었지만 이에 대응할 수 있는 수단의 확충에는 소홀히 하였다. 따라서 한국은행이 물가상승률 목표제와 금융안정을 동시에 달성하기 위해선 거시건전성 정책 수단의 확충이 필수적이다. 이를 위해 가장 손쉽게 시도해 볼 수 있는 방안은 금융위원회의 설치 등에 관한 법률을 개정하여 한국은행이 거시건전성 정책 운영에 참여하도록 하는 것이다. 즉 “금융위원회는 중요한 거시건전성정책을 결정할 때 이를 한국은행과 반드시 협의한 후 금융위원회에 부의해야 한다”라고 명시하는 것이다. 동시에 거시건전성정책에 대한 한국은행의 책임도 명시화할 필요가 있다. 보다 장기적인 관점에서 근본적으로 거시건전성 정책체계를 바꿀 수 있다는 가정을 염두에 두고 새로운 시스템을 설계하자면 다음의 세 가지 방안을 생각해 볼 수 있다. [방안 1]은 시스템 위기를 전담하는 금융안정위원회(가칭)를 상설기구로 신설하고 동 위원회에서 거시건전성 정책을 의결하도록 하는 것이다. [방안 2]는 거시건전성 정책의 주체로 한국은행을 지정하는 것이다. [방안 3]은 금융감독체계를 전면 개편하여, 한국은행으로 하여금 거시건전성 정책을 포함한 금융 건전성감독 전반을 책임지게 하는 것이다. 영국은 금융위기 이후 법체계를 정비하여 이러한 방안을 채택하였다. 하지만 [방안 3]을 채택하기 위해서는 전면적인 금융감독체계의 개편을 필요로 한다는 점에서 현실적으로 한계가 있다. Under the current economic environment characterized by slow growth, low inflation and financial instability, ojectives of central bank have expanded to include financial stability in addition to the traditional objectives of price and employment stability. This paper studies what the proper role of the Bank of Korea (BOK) should be in conducting macroprudential policy to enhance financial stability. This paper proposes that BOK should attempt to stabilize output while maintaining the flexible inflation targeting policy. The global financial crisis shows that price and output stability does not gaurantee financial stability and that financial instability can adversely affect price and output stability in turn. Therefore, the central bank should actively engage in achieving financial stability in advance. Monetary policy itself would not be sufficient to achieve financial stability. BOK needs proper tools to conduct macroprudential policy to satisfy the objective of financial stability added to the BOK Bylaws in 2011. One practical way is to amend the Bylaws to require that the Financial Supervisory Commission (FSC) should consult with BOK in macroprudential policy making process. At the same time, it is necessary to be explicit about the responsibility of BOK. For long-term solution, we suggest three proposals: (1) establishing the “Committee for Financial Stability” who is responsible for all policy making regarding macroprudential policy; (2) designating BOK as the main institution for macroprudential policy; (3) making BOK responsible for all policies regarding financial stability, replacing the role of FSC, following the case of U.K. in the post global financial crisis period. However, the last proposal is not so easy to implement in practice because it requires the overhaul of the whole banking and financial supervisory structure.

Application of Systems Engineering in Shipbuilding Industry in Korea

Kim, Jinil,Park, Jongsun The Korean Society of Systems Engineering 2011 시스템엔지니어링학술지 Vol.7 No.2

Modern naval ships are large complex systems with the number of requirements ranges from thousands to tens of thousands. To build a quality ship, the satisfaction of the requirements should be traced. In most shipbuilding projects it is almost impossible to manage all the requirements without a proper CASE (computer aided systems engineering) tool. And for effective management of the shipbuilding project, the integrated database for technical data is very important. This paper describes how the requirements are managed, and the integrated database is built in the naval shipbuilding industry in Korea.

The influence of tube and membrane structure on dynamic instability in furnace wall tubes of a fossil fired once-through in a simulated furnace environment

Jinil Kim,최상민 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.11

A numerical model was developed to investigate dynamic instability in fossil fired once through boilers and the influence of the dynamics of tube and membrane structure furnace wall tubes on the stability boundary was examined. In order to predict density wave oscillation (DWO), the most common type of dynamic instability, a time domain nonlinear analysis approach was used to give a transient flow field in the tubes. The tubes were divided into one-dimensional finite volumes along their lengths and equations of conservation of mass, momentum and energy were discretized to give algebraic equations. The SIMPLE algorithm was adopted to solve these equations. Analysis of two-dimensional transient conduction across a tube-membrane section of each volume was performed concurrently and the resulting heat transfer between tube inner wall and fluid was included in the source term of the energy equation. After verification with results in available literature, the model was applied to a wall tube section of a 700 MW boiler furnace in subcritical once-through condition. The stability boundaries for three types of tube configuration were predicted, and it was found that the dynamics of tube configuration can have a significant effect on the flow instability in the boiler furnace wall tubes.

Conditional Versus Unconditional Utility as Welfare Criterion: Two Examples

Kim, Jinill,Kim, Sunghyun Springer-Verlag 2018 Computational economics Vol.51 No.3

<P>This paper provides two illustrative examples on how a choice of social welfare criterion (conditional vs. unconditional utility) can generate different welfare implications. The first example is based on the standard linear-quadratic permanent income model, and the other example uses a simple two-country DSGE model under autarky and under complete markets. When the conditional welfare criterion is used-with the social discount factor set at the private discount factor-we obtain the well-known results that the government should not intervene when there are no market imperfections and that complete markets generate risk sharing gains over autarky. In contrast, using an unconditional welfare criterion-which effectively implies that the social discount factor is set to unity-can generate unconventional welfare results.</P>

Welfare of Incomplete Markets Economy with Permanent as well as Transitory Shocks

Jinill Kim 서울대학교 경제연구소 2002 Seoul journal of economics Vol.15 No.3

Under the assumption that shocks are transitory, the welfare properties of the incomplete markets economy with only bonds are well known. As agents become more patient, its behavior get closer to that of the complete markets economy. As shocks become more persistent, the incomplete markets economy behave much differently from the complete markets economy. This paper shows that, when shocks have permanent as well as transitory components, neither of these two properties is true. More patience does not always move the incomplete markets economy closer to the complete markets economy, and more persistence in growth rate shocks induces similarity between the incomplete markets economy and the complete markets economy.

A New Measure for Core Inflation Based on Generalized Dynamic-Factor Model

Kim, Jinill,Ahn, Byung Kwun 한국은행 2012 經濟分析 Vol.18 No.2

Many central bankers pay attention to measures for core inflation when deciding how to adjust policy from meeting to meeting even though their statutory targets are set in terms of headline inflation. It is because what central bankers are truly concerned with is underlying inflation going forward. For example, while the official target is set in terms of headline CPI inflation, the Bank of Korea considers a variety of core inflation measures. However, those core inflation measures are somewhat volatile and do not provide a reliable signal of medium-term underlying inflation. Continuing inflation in oil and food prices causes headline CPI inflation rate to deviate from core inflation measures for an extended period of time. In order to provide a clearer picture of underlying inflation pressures to policy makers, we need to develop a new core inflation measure that tracks underlying inflation more closely. Consistent with the current objective of the Bank of Korea that is based on headline CPI inflation, we review several core inflation measures that have been used or proposed by various authors - including those currently used by the Bank of Korea - and propose a new core inflation measure that is based on generalized dynamic-factor modeling. We discuss the behavior of our proposed core inflation measure starting in the 1990s and show that it performs better than the conventional core inflation measures that are currently used.

Indeterminacy under Social Constant Returns and Costs of Adjusting Capital

Jinill Kim THE KOREAN ECONOMIC SOCIETY 2012 JOURNAL OF ECONOMIC THEORY AND ECONOMETRICS Vol.23 No.3

It has been shown that, in a small open economy with traded and nontraded goods, indeterminacy occurs under constant returns to scale for the social technology with an arbitrarily small degree of externalities. This paper claims that costs of adjusting capital increase the required degree of externalities for indeterminacy to arise. Under empirically plausible levels of adjustment costs and externalities, indeterminacy does not arise in a model with social constant returns.