Yerim Chung - Academia.edu (original) (raw)

Papers by Yerim Chung

The Korean Society Of Computer And Information, 2019

Innovation Enterprise Research

Journal of Korea Technology Innovation Society

Korean Operations Research And Management Society, Mar 1, 2013

Journal of the Korea Society of Computer and Information, Oct 1, 2019

In this paper, we study a polynomially solvable case of the inverse interval graph coloring probl... more In this paper, we study a polynomially solvable case of the inverse interval graph coloring problem. Given an interval graph associated with a specific interval system, the inverse interval graph coloring problem is defined with the assumption that there is no proper -coloring for the given interval graph, where  is a fixed integer. The problem is to modify the system of intervals associated with the given interval graph by shifting some of the intervals in such a way that the resulting interval graph becomes -colorable and the total modification is minimum with respect to a certain norm. In this paper, we focus on the case    where all intervals associated with the interval graph have length 1 or 2, and interval displacement is only allowed to the righthand side with respect to its original position. To solve this problem in polynomial time, we propose a two-phase algorithm which consists of the sorting and First Fit procedure.

The Knowledge Management Society of Korea, Sep 1, 2016

Journal of the Korea Society of Computer and Information, Sep 1, 2019

In this paper, we study the university timetabling problem, which consists of two subproblems, th... more In this paper, we study the university timetabling problem, which consists of two subproblems, the university course timetabling problem and the examination timetabling problem. Given a set of classrooms, students, teachers, and lectures, the problem is to assign a number of courses (and examinations) to suitable timeslots and classrooms while satisfying the given set of constraints. We discuss the modeling and solution approaches to construct course and examination timetables for one of the largest Korean university. By using binary integer programming formulations, we describe these two complex real-world problems. Then, we propose a solution method, called NOGOOD, to solve the examination timetabling model. The computation results show that NOGOOD finds the optimal examination schedule for the given instance. Although we consider a specific instance of the university timetabling problem, the methods we use can be applicable to modeling and solving other timetabling problems.

Journal of The Korean Chemical Society, 2018

The Korean Society Of Hospital Administration, Sep 1, 2018

Journal of the Korea Society of Computer and Information, 2021

Yonsei Business Review, 2021

European Journal of Operational Research, 2022

본 논문에서는 대규모 물류 시스템의 최적제어를 위하여, 계층적 분산 제어이론을 적용하여, 수치해법 알고리즘을 검토하고, 이를 적용 예제에서 테스트 하여본다. 알고리즘은 연결된... more 본 논문에서는 대규모 물류 시스템의 최적제어를 위하여, 계층적 분산 제어이론을 적용하여, 수치해법 알고리즘을 검토하고, 이를 적용 예제에서 테스트 하여본다. 알고리즘은 연결된 고리의 동적 시스템에서 잘 활용될 수 있도록 고안 하였으며, 시스템을 선형 미분 방정식으로 모형화 하고,목적함수는 볼록 2차함수로 설정 했으며, 최적조건을 유도하였고, 수치해법을 검토하였다. 그리고 여러 예제의 수치해를 구하여 알고리즘의 수렴을 검토하였다.

We examine the characteristics, methodologies, and general trends in social media studies publish... more We examine the characteristics, methodologies, and general trends in social media studies published in journals listed in the SSCI indexes from 2006 to 2013. A total of 437 articles published were examined with a content analysis. Our analysis focuses on the papers’ topics, subjects of analysis, methods, perspectives, and theoretical perspectives. The results show that the number of published social media studies dramatically increased from 2008. Descriptive analyses of users and the role of social media in social interactions were the predominant subjects of the articles. Individual-level of analysis and quantitative research methods were mainly used in social media researches. Social media researches have become independent fields in psychology and communication. Our study serves as the foundation from which to assess current findings and offers some recommendations for future research on social media, including the rigor and diversity of research methodologies, multidisciplinary ...

Antioxidants, 2021

Panax ginseng Meyer is used as a medicinal plant. The aim of this study was to ferment hydroponic... more Panax ginseng Meyer is used as a medicinal plant. The aim of this study was to ferment hydroponic ginseng with Lactococcus lactis KC24 and confirm its antioxidant activity and inhibitory effect on nitric oxide (NO) production. Flavonoid and phenol contents in fermented ginseng extracts were measured. Antioxidant activity was measured by DPPH, ABTS, reducing power, FRAP and β-carotene assays. Additionally, inhibitory effects on NO production and toxicity of the fermented extract were determined using RAW 264.7 cells. Phenol and flavonoid contents increased as the fermentation time increased, and the contents were higher in hydroponic ginseng than in soil-cultivated ginseng. The DPPH assay revealed that the antioxidant activity of the 24 h fermented extract significantly increased from 32.57% to 41% (p < 0.05). The increase in antioxidant activity may be affected by an increase in phenol and flavonoid contents. At 1 mg/mL solid content, the 24 h fermented hydroponic ginseng extract...

LWT, 2020

Probiotic characteristics of Lactobacillus brevis B13-2 isolated from kimchi and investigation of... more Probiotic characteristics of Lactobacillus brevis B13-2 isolated from kimchi and investigation of antioxidant and immune-modulating abilities of its heat-killed cells