Level Set Methods and Image Processing

Myungjoo Kang 한국산업응용수학회 2005 한국산업응용수학회 학술대회 논문집 Vol.- No.-

Using modern techniques from scientific computing and numerical analysis, natural phenomena or scientific experiment can be simulated effectively with a computer and used for computer graphics, for example as special effects for the film industry and manufacturing the thin film. The Level Set Methods can make those things happen without a lot of difficulties. This method was devised by Osher and Sethian(1988) to represent dynamically moving interfaces as the zero level set of a scalar function that evolves in time. Since then, many researchers have worked on many applications using a Level Set Methods. I will introduce the recent developments using the Level Set Methods which are including Fluid Simulation, Image Processing, Geometric Optics, Geospatial Data Compression.

THE MATHEMATICAL MODELING AND NUMERICAL SIMULATIONS FOR THE MOTION OF SOAP BUBBLES

Myungjoo KANG 한국산업응용수학회 2006 한국산업응용수학회 학술대회 논문집 Vol.1 No.2

In this paper, we develop the appropriate equations for bubble motions depending on curvature using the level set methodology. Our method consists of an appropriate finite difference scheme for solving our model equations and a level set approach for capturing the complicated motion between the bubbles. Results indicate that our models and the level set methods can handle complicated interfacial motions and topology changes, and that they can numerically simulate many of the physical features of bubble motions.

The Effects of Internal Marketing and Career Motivation for the PROTECTION of Dermatology Hospital Workers on Job Satisfaction and Organizational Commitment

Myungjoo Kim,Eunsook Kim J-INSTITUTE 2021 Protection Convergence Vol.6 No.2

Purpose: The purpose of this study is to provide implications for efficient manpower management and suc-cessful organizational performance by identifying the influential factors that internal marketing and career mo-tivation have on job satisfaction and organizational commitment for medical skincare workers Method: This study used the SPSS 22.0 program as an empirical method of analyzing 350 copies of an online survey conducted among medical skincare workers in 17 cities and provinces nationwide and performed multi-ple regression analysis to examine the effects of internal marketing and career motivation on job satisfaction and organizational commitment. Results: As a result of this study, the hypothesis 1, internal marketing will affect job satisfaction, showed that internal communication has a significant positive(+) effect on intrinsic satisfaction and management support, internal communication, and compensation systems have a significant positive(+) effect on extrinsic satisfaction. In the hypothesis 2, career motivation will affect job satisfaction, it was found that career insight, career resili-ence, and career identity have a significant positive(+) effect on intrinsic satisfaction while career resilience and career identity have a significant positive(+) effect on extrinsic satisfaction.Similarly,in hypothesis 3, job satis-faction will affect organizational commitment, intrinsic satisfaction and extrinsic satisfaction were found to have a significant positive(+) effect on organizational commitment. Conclusion: Identifying and presenting internal marketing factors to achieve career goals and satisfy workers through this studyiscrucial for organizational performance.Therefore, it is deemed necessary to provide oppor-tunities for career development activities through smooth communication between management and workers, education, training, and compensation policiesto protect the work of medical skincare workers by creating a work environment that satisfies and encourages them to actively concentrate on their work even in unfavorable situations.

NUMERICAL COMPARISON OF WENO TYPE SCHEMES TO THE SIMULATIONS OF THIN FILMS

MYUNGJOO KANG,CHANG HO KIM,YOUNGSOO HA 한국산업응용수학회 2012 Journal of the Korean Society for Industrial and A Vol.16 No.3

This paper is comparing numerical schemes for a differential equation with convection and fourth-order diffusion. Our model equation is ht + (h² - h³)x = -(h³hxxx)x, which arises in the context of thin film flow driven the competing effects of an induced surface tension gradient and gravity. These films arise in thin coating flows and are of great technical and scientific interest. Here we focus on the several numerical methods to apply the model equation and the comparison and analysis of the numerical results. The convection terms are treated with well known WENO methods and the diffusion term is treated implicitly. The diffusion and convection schemes are combined using a fractional step-splitting method.

Is OCIO superior in asset allocation performance?

( Myungjoo Kang ),( Inwook Song ),( Seiwan Kim ) 한국파생상품학회 2023 선물연구 Vol.31 No.2

This study aims to empirically analyze the asset allocation capabilities of Outsourced Chief Investment Officers (OCIOs) in Korea. The empirical analysis used data from 35 funds that were evaluated by the Ministry of Strategy and Finance from 2012 to 2020. The results of the analysis are summarized as follows. First, this study found that funds that adopted OCIO improved their asset allocation performance. Second, the sensitivity between risk-taking and performance decreased for funds that adopted OCIO. Third, it is found that OCIO adoption improves a fund’s asset management execution (tactical capabilities). This study has methodological limitations in which the methodology used in this study is not based on theoretical prior research, but on practical applications. However, considering the need to clearly analyze the capabilities of OCIO and the timeliness of the topic, this study is valuable and can provide meaningful information to funders who are considering adopting OCIO in the future.

Analytic solution for American strangle options using Laplace–Carson transforms

Kang, Myungjoo,Jeon, Junkee,Han, Heejae,Lee, Somin Elsevier 2017 Communications in nonlinear science & numerical si Vol.47 No.-

<P><B>Abstract</B></P> <P>A strangle has been important strategy for options when the trader believes there will be a large movement in the underlying asset but are uncertain of which way the movement will be. In this paper, we derive analytic formula for the price of American strangle options. American strangle options can be mathematically formulated into the free boundary problems involving two early exercise boundaries. By using Laplace–Carson Transform(LCT), we can derive the nonlinear system of equations satisfied by the transformed value of two free boundaries. We then solve this nonlinear system using Newton’s method and finally get the free boundaries and option values using numerical Laplace inversion techniques. We also derive the Greeks for the American strangle options as well as the value of perpetual American strangle options. Furthermore, we present various graphs for the free boundaries and option values according to the change of parameters.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We derive analytic formula of Laplace–Carson transforms (LCT) for the price of American strangle options. </LI> <LI> By LCT, we can derive the nonlinear system of equations satisfied by the transformed value of two free boundaries of American strangle option. </LI> <LI> We then solve this nonlinear system using Newton’s method and finally get the free boundaries and option values using numerical Laplace inversion techniques. </LI> </UL> </P>

VoIP 서비스의 음성 품질에 대한 연구

채명주(MyungJoo Chae),조평동(PyungDong Cho),유승화(SeungWha Yoo) 한국통신학회 2000 한국통신학회 학술대회논문집 Vol.2000 No.11

『이운지(怡雲志)』 「절신상락(節辰賞樂)」에 관한 소고(小考)

심명주 ( Shim Myungjoo ) 이화여자대학교 한국문화연구원 2021 한국문화연구 Vol.41 No.-

「절신상락(節辰賞樂)」은 『임원경제지 이운지』 제8권 말미에 수록되어 있는 세시에 따른 풍속과 놀이에 관한 저술로서, 조선후기 세시풍속 및 놀이와 관련된 상세한 내용과 함께 서유구(徐有榘, 1764~1845)만의 독특한 관점과 지향이 반영된 저술 특색을 보여준다. 18세기 말에서 19세기 중반사이에 조선의 세시풍속과 관련하여 체계를 갖춘 저술들이 다수 출현하는데, 『경도잡지』, 『열양세시기』, 『동국세시기』가 조선후기를 대표하는 3대 세시기로 알려져 있다. 이와 비슷한 시기에 저술된 것으로 추정되는 서유구의 「절신상락」은 그간 『임원경제지』의 방대한 내용 속에 묻혀 본격적인 세시풍속기로 거의 주목받지 못한 측면이 있다. 본고에서는 먼저 「절신상락」이 조선후기 3대 세시기에 비견할 만한 세시풍속 자료로 중요성을 갖는다는 점을 밝히기 위해 두 가지 점에 주목하고자 한다. 첫번째로 「절신상락」의 구성과 내용을 살펴 서유구가 3대 세시기의 내용을 모두 포괄하며 일 년의 세시풍속을 독자적인 관점에서 재구성한 점과, 세시 풍속과 놀이를 향촌의 실생활에서 유용하게 사용할 방안에 대해 고민한 측면을 살펴보기로 한다. 두 번째로 「절신상락」이 한양을 중심으로 한 기존 세시풍속서의 고증을 위주로 한 서술을 뛰어넘어, 향촌 공동체 구성원들의 소통과 화합을 위한 놀이문화와 일상생활 지침서로서 저술되었다는 점을 살펴 서유구가 지향하는 향촌 생활 공동체의 면모를 이해해 보도록 한다. This essay discusses seasonal customs manuals in 「Jeolsin-Sangnak(節辰賞樂)」. described in ‘Yiwunji (怡雲志)’ of ImwonGyeongjeji (林園經濟志). The writing shows the characteristics that reflects his unique perspective and orientation. In the late Joseon Dynasty, the Three Major Almanacs(Sesigi)- Gyeongdojapji(京都雜志), Yeolyang-sesigi(列陽歲時記), and Dongguk-sesigi (東國歲時記) was published. Seo Yu-gu's 『Jeolsin Sangnak』, presumed to have been written around the same time, but has been hidden in the vast content of 『Imwon Gyeokji』 so that it has received little attention as a full-fledged seasonal customs manual. This paper debates two major topics in order to clarify the importance of Jeolsin-Sangnak as a seasonal customs manual comparable to the Three Major Almanacs(Sesigi). First, by examining the composition and contents of 「Jeolsin Sangnak」, Seo Yu-gu not only covers all the contents of the Three Major Almanacs(Sesigi), but with his perspectives and understanding of seasonal customs considers seasonal manuals’s practical application in the rural life. Second, this paper will discuss the fact that 「Jeolshin-Sangnak」 was written as a guide book for communication and harmony among members of rural communities, also going beyond the narratives which focused on the historical evidence of Hanyang oriented seasonal customs. Therefore, this paper has developed existing discussions about seasonal customs manual to examine the specific characteristics and the contents of Seo Yu-gu’s ideal rural living community.

보행자 속도 변경 행태의 영향요인 분석

한명주(HAN, Myungjoo),정동재(JUNG, Dongjae),이영인(LEE, Young-Ihn),신성일(SHIN, Seongil) 대한교통학회 2018 대한교통학회지 Vol.- No.-

삶의 질 향상과 지속가능 발전에 대한 관심이 커지면서 보행 편의 증진에 대한 사회 요구가 높아지고 있다. 보행관련 사업 및 정책을 효과적으로 추진하기 위해서는 보행자 행태에 대한 이해가 우선되어야 한다. 그러나 보행자가 어떤 보행환경에서 불편함을 느끼고 기존 보행 속력과 방향을 변경하는지, 어떤 보행자 특성 그룹이 보행환경에 민감한지 등에 관한 정보는 여전히 부족하다. 이 연구는 보행자가 기존의 보행 속력 또는 방향을 어떤 조건에서 바꾸려 하는지를 분석하였다. 또한 이 선택의 경향이 보행자 특성 그룹간에 차이가 있는지를 검토하였다. 이를 위해 이 연구는 보행자에게 가상적인 보행 환경을 제시하고 보행 속도를 유지 또는 변경할 것인지를 묻는 이산선택실험 기반의 진술선호 조사를 실시하였다. 장애물 또는 다른 보행자와 거리, 각도, 상대 속력, 보행밀도를 포함하는 사회적 보행환경과 보행공간의 폭, 경사와 같은 물리적 보행환경, 연령, 성별, 통행목적, 통행빈도와 같은 보행자 특성이 보행속도 변경 행태에 미치는 영향은 이항로짓 모형으로 규명하였다. 그 결과 장애물 또는 다른 보행자와 거리가 가까울수록, 측면보다 정면에 장애물이 있을수록, 장애물 또는 다른 보행자의 상대속력이 느릴수록, 보행공간의 폭이 좁을수록 보행 속력 또는 방향을 변경하는 선택 경향이 통계적으로 유의하게 높은 것으로 나타났다. 또한 고령자일수록 보행 속력 또는 방향의 변경 가능성은 줄었다. 비업무목적 보행자에 비해 업무목적 보행자가 보행속도를 변경할 가능성이 높았다. 성별에 따라서도 뚜렷한 차이가 있었다. 반면 보행공간의 혼잡수준, 경사, 통행빈도에 따른 보행 속도 선택 경향의 차이는 통계적으로 유의하지 않았다. 이 연구는 첫째, 미시적 관점으로 개별 보행자 단위의 보행정책 효과 또는 서비스수준을 평가하는 방안에 관한 시사점을 제공한다. 예컨대 보행자가 속도를 변경할 가능성이나 기대횟수가 평가지표로 고려될 수 있다. 둘째, 이 연구의 결과는 미시적 관점의 보행행태 시뮬레이터 개발에 기초 자료로 활용될 수 있다는 점에서 앞으로 그 중요성과 활용도가 높아질 것으로 기대된다. As interest in quality of life improvements and sustainable development has increased, societal need for walking expediency promotion is rising. In order to effectively promote walking related projects and policies, an understanding of pedestrian behavior must take precedence. However, information including, among others, the types of walking environments in which pedestrians feel uncomfortable and thus alter their existing walking speed and direction, and the types of pedestrian attribute groups that are particularly sensitive to walking environments is still insufficient. In this study, we analyze conditions under which the pedestrian changes their existing walking speed and direction. We also examine whether the tendency of this selection is different between pedestrian attribute groups. In order to achieve this, the research is conducted using a stated preference survey based on discrete choice experiments, asking for a preference between a maintenance or change in walking velocity in a virtual walking environment. Influences on changes in walking velocity is determined using the binary logit model for the following factors: (1) the social walking environment, including attributes such as distance, angle, relative speed, walking density with respect to another pedestrian or obstacle, (2) the physical environment regarding the width of the walking space and its slope, and (3) individual pedestrian attributes such as age, gender, trip purpose, and trip frequency. The result show that closer distance to the obstacle or other pedestrian, obstacles positioned in front than to the side, slower relative speeds of the obstacle or other pedestrians and narrower width of the walking space have statistical significance in affecting the change in walking speed and direction. Other findings from this research, we found that older people have lower likelihood of changing their walking speed and direction. Compared to non-business purpose trip pedestrians, the likelihood of pedestrians on business-purpose trips changing their walking velocity was higher. There was also a clear difference between genders. On the other hand, there was no statistical significance between differences in selection tendency of walking velocity according to congestion level, slope, and pass frequency in the walking space. With these findings, we first provide insights on how to evaluate walking policy effects and service levels for individual pedestrians from a micro-level perspective. For example, the possibility that a pedestrian changes velocity or the expected number of changes in velocity can be taken into consideration as an evaluation index. Secondly, the fact that results of this research can be utilized as basic data for the development of a walking behavior simulator at the micro-level will increase its importance and utilization factor in the future.

『이운지(怡雲志)』의 농업공간에 관한 고찰

심명주 ( Shim Myungjoo ) 이화여자대학교 한국문화연구원 2019 한국문화연구 Vol.36 No.-

본고는 『임원경제지(林園經濟志)』 『이운지(怡雲志)』 권1 「형비포치(衡泌鋪置)」에 수록된 ‘농업 공간’에 관한 연구이다. ‘은자가 살아가는 집의 배치’라는 의미를 지니는 「형비포치」에는 향촌 거주와 관련된 다양한 접근과 구상이 수록되어 있는데, 본고에서는 이러한 다양한 내용 중 ‘농업 공간’에 국한해 논의를 진행하였다. 구체적인 논의에 앞서 제2장에서는 향촌 농업생산 공간의 전제라 할 수 있는 입지와 관련된 문제를 다루어 보았다. 서유구는 상택지에서 ‘복거사요’에 관해 언급하며 생업 활동이 가능하고 지리적, 사회적, 심미적 환경 조건이 구비된 곳을 ‘낙토’라 부르고 있는데, 낙토의 조건 중 가장 중요한 것이 지리적 조건과 함께 생계를 위한 농업 활동을 영위할 수 있는 제반 환경이라 밝히고 있다. 제3장의 농업 공간에 관한 제안에서는, 먼저 서유구가 구상했던 농업공간의 특색과 상세한 내용 및 함의에 대하여 알아보았다. 서유구는 이운지의 농업공간에 ‘사(社)’라는 명칭을 부여하며, 이들이 향촌의 ‘자치적 공동체’의 성격을 지니고 있음을 암시하고 있으며, 이들 공간에는 『임원경제지』에 집적된 서유구의 지식과 이상이 반영되어 있음도 살필 수 있다. 논농사를 위한 공간인 행포사는 지식과 노동력의 협력을 도모하여 운영하는 향촌의 공동 농업을 위한 ‘농업관제 센터’의 성격을 가지고 있고, ‘포정’의 경우 새로운 농법을 실험해 보는 공간으로 구상되었다. ‘전어사’는 향촌의 대규모 목축어업을 위한 단지의 구상이며, ‘경솔지사’는 양잠과 길쌈이 한 공간 안에서 모두 이루어질 수 있는 ‘통합 공간’을 구성하여 작업의 효율을 극대화 하고자 한 구상도 살펴 볼 수 있다. 지금까지 이운지의 공간에 대한 연구는 사대부의 심미적 취향을 반영한 공간 혹은 공간이 가진 공공성의 중요성에 대한 논의까지 진행된 바 있다. 본고에서 다룬 농업 공간에 관한 고찰의 중요성은 서유구가 공간 속에서 반영하고자 한 농업 개선과 관련된 구상과 이러한 구상이 반영된 공간의 구체적인 내용과 의미를 살펴본 점에 있다고 하겠다. This paper discusses agricultural spaces as described by Seo Yu-gu. The agricultural spaces described in ‘Yiwunji (怡雲志)’ of ImwonGyeongjeji (林園經濟志), Treatises on Management of Rural Life, consist of four different kinds: The first is the Hangposa (杏蒲社) which is a space for rice farming; the second is Pojeong (圃亭) for dry-field farming; the third is Jeoneosa (佃漁社), the space for livestock farming and fisheries; and lastly, Chungyeongryo (春鶊寮) and Chusolwa (秋蟀窩) for sericulture and weaving. These four types of space all contain the academic ideals of Seo Yu-gu, accumulated in ImwonGyeongjeji. The most important thing that can be learned from the analysis of the spaces is that he made an attempt to create an agricultural community; he organized an autonomous community of a village to devise a plan to increase agricultural production in the form of combined knowledge and labour. Second, it illustrates Seo Yu-gu ’s thoughts on agricultural management. It seems that he also considered selling the products outside the village beyond self-sufficiency by creating an integrated production space for a large-scale livestock fishing complex and sericulture enterprise. In addition, it can be seen that Seo Yu-gu was trying to test his new farming methods in these spaces. In Pojeong, Seo Yu-gu suggests the use of two farming methods together to increase the production of dry-field farming. It is thought that, in this way, he tried to experiment with many agricultural ideas he studied, as well as to reflect his ideal through the space of Hyungbipochi (衡泌鋪置). Until now, studies on the space of Hyungbipochi have been limited to discussions of space that reflect the personal taste of the nobility or the public nature of the space. Therefore, this paper has developed existing discussions to examine the specific characteristics of the agricultural spaces and identified that the contents of Seo Yu-gu’s ideal agriculture.