Development of methodology for daily rainfall simulation considering distribution of rainfall events in each duration

Jung Jaewon,Kim Soojun,Kim Hung Soo 한국수자원학회 2019 한국수자원학회논문집 Vol.52 No.2

기존의 Markov Chain 모형으로 일강우량 모의시에 강우의 발생여부를 모의하고 강우일의 강우량은 Monte Carlo 시뮬레이션을 통해 일강우 분포 특성에 맞는 분포형에서 랜덤으로 강우량을 추정하는 것이 일반적이다. 이때 강우 지속기간에 따른 강도 및 강우의 시간별 분포 등의 강우 사상의 특성을 반영할 수 없다는 한계가 있다. 본 연구에서는 이를 개선하기 위해 강우 사상을 1일 지속강우, 2일 지속강우, 3일 지속강우, 4일이상 지속강우로 구분하여 강우의 지속기간에 따라 강우량을 추정하였다. 즉 강우 사상의 강우 지속일별로 총강우량의 분포형을 비매개변수 추정이 가능한 핵 밀도추정(Kernel Density Estimation, KDE)를 적용하여 각각 추정하였고, 강우가 지속될 경우에 지속일별로 해당하는 분포형에서 강우량을 구하였다. 각 강우사상에 대해 추정된 총 강우량은 k-최근접 이웃 알고리즘(k-Nearest Neighbor algorithm, KNN)을 통해 관측 강우자료에서 가장 유사한 강우량을 가지는 강우사상의 강우량 일분포 형태에 따라 각 일강우량으로 분배하였다. 본 연구는 기존의 강우량 추정 방법의 한계점을 개선하 고자 하였으며, 연구 결과는 미래 강우에 대한 예측에도 활용될 수 있으며 수자원 설계에 있어서 기초자료로 활용될 수 있을 것으로 기대된다. When simulating the daily rainfall amount by existing Markov Chain model, it is general to simulate the rainfall occurrence and to estimate the rainfall amount randomly from the distribution which is similar to the daily rainfall distribution characteristic using Monte Carlo simulation. At this time, there is a limitation that the characteristics of rainfall intensity and distribution by time according to the rainfall duration are not reflected in the results. In this study, 1-day, 2-day, 3-day, 4-day rainfall event are classified, and the rainfall amount is estimated by rainfall duration. In other words, the distributions of the total amount of rainfall event by the duration are set using the Kernel Density Estimation (KDE), the daily rainfall in each day are estimated from the distribution of each duration. Total rainfall amount determined for each event are divided into each daily rainfall considering the type of daily distribution of the rainfall event which has most similar rainfall amount of the observed rainfall using the k-Nearest Neighbor algorithm (KNN). This study is to develop the limitation of the existing rainfall estimation method, and it is expected that this results can use for the future rainfall estimation and as the primary data in water resource design.

Global Productivity and Market Structure Implications of the US-China Trade War: A CGE Modeling Approach

Jaewon Jung 한국무역학회 2020 Journal of Korea trade Vol.24 No.8

Purpose – As the US-China trade war intensifies and lasts long time, there is growing concern about its potential effects on the global economy. In particular, for the countries like Korea that have a large economic dependence on the economy of the two countries, the US-China trade war may have a great repercussion in many ways. The aim of this paper is to investigate the global productivity and market structure implications of the US-China trade war for Korea, as well as for other surrounding countries and regions. Design/methodology – In this paper, we develop a full multi-country/region multi-sector computable general equilibrium (CGE) model of global trade incorporating heterogeneous workers and firms in individual skill levels and used technologies. We then calibrate the model using a global Social Accounting Matrix (SAM) dataset extracted from the recently released GTAP 10 Database, and assess the potential effects of the US-China trade war on the aggregate real productivity and the market structure for Korea, as well as for other surrounding countries and regions. Findings – We show that the US-China trade war may largely affect the aggregate productivity in each sector in each country/region, as well as the global market structure through entry and exit of firms, which results finally in considerable changes in the industrial comparative advantage of each country/region. Though the effects are diverse sector by sector, the results show that Korea may also be affected significantly: concerning the real productivity implications, it is shown that the machinery industry may be affected the most negatively; on the other hand, it is shown that the number of exporting firms may decrease the most in the other transports industry. Originality/value – As the US-China trade war intensifies, many studies have tried to estimate the possible implications, and for this usually the CGE models have largely been used as the standard tool for evaluating the impacts of changes in trade policies. Standard CGE models, however, cannot be used to assess the global productivity and market structure implications due to the symmetric and simplified base assumptions. This paper is the first to analyze and quantify the possible impacts of the US-China trade war on the aggregate productivity and global market structure using a CGE model incorporating endogenous skill-technology assignment of heterogeneous workers and firms.

The effect of personalized bowel preparation using the smartphone camera application: A pilot study

( Jaewon Jung ),( Jongha Park ),( Seunghyun Park ),( Ju Won Lee ),( Jonghwa Park ),( Gi Jung Jeon ) 대한내과학회 2015 대한내과학회 추계학술대회 Vol.2015 No.1

Background: Despite several attempts to improve the bowel preparation quality, they were not enough improved patients’ satisfaction and compliance during bowel preparation for colonoscopy. We aimed to investigate the effectiveness of the smartphone application which analyze and judge the optimal dosage of polyethylene glycol (PEG) for bowel preparation. Design: This prospective randomized controlled trial was investigator-blinded. Patients were assigned to usethe smartphone camera application (app group, n=30) for bowel preparation or just received the written instructions (non-app group, n=30). The app group used the smartphone camera application which was programmed to judge the bowel preparation quality automatically from the bowel preparation status. Application let them stop taking more PEG solution if their bowel preparation was appropriate as “pass or fail”. In contrast the non-app group took 4 liters of PEG solution as the provided manual. Results: The primary outcome was the quality of bowel preparation based on blinded ratings by the Ottawa bowel preparation scale (OBPS). The secondary outcomes were the difference of dosage of PEG between two groups and the acceptability of the camera application in the app group. The primary outcome showed no statistically significant difference of OBPS total score between the two groups (mean OBPS 2.53 ±1.264 vs. 2.79 ± 2.064, p=0.950). The secondary outcomes revealed that the app group took lower dose of PEG than non-app group (mean dosage (mL): 3713.16 ± 405.81 vs. 3979.17 ±102.06, p=0.001). The acceptability of the camera application showed good response in the app group (5-point Likert scale; 1=not acceptable, 5=very acceptable; mean score 4.37± 0.895, p<0.001). Conclusions: Although taking lower dose PEG, the bowel preparation using the smartphone camera application showed the similar quality of bowel preparation compared to conventional preparation group. Moreover, personalized bowel preparation using the smartphone camera application enhanced compliance of bowel preparation and patients’ satisfaction.

Improving visual relationship detection using linguistic and spatial cues

Jung, Jaewon,Park, Jongyoul Electronics and Telecommunications Research Instit 2020 ETRI Journal Vol.42 No.3

Detecting visual relationships in an image is important in an image understanding task. It enables higher image understanding tasks, that is, predicting the next scene and understanding what occurs in an image. A visual relationship comprises of a subject, a predicate, and an object, and is related to visual, language, and spatial cues. The predicate explains the relationship between the subject and object and can be categorized into different categories such as prepositions and verbs. A large visual gap exists although the visual relationship is included in the same predicate. This study improves upon a previous study (that uses language cues using two losses) and a spatial cue (that only includes individual information) by adding relative information on the subject and object of the extant study. The architectural limitation is demonstrated and is overcome to detect all zero-shot visual relationships. A new problem is discovered, and an explanation of how it decreases performance is provided. The experiment is conducted on the VRD and VG datasets and a significant improvement over previous results is obtained.

Openness, Productivity and Welfare with Heterogeneous Firms

JUNG Jaewon 한국무역학회 2017 한국무역학회 국제학술대회 Vol.2017 No.11

Label-Free Flexible DNA Biosensing System Using Low-Temperature Solution-Processed In-Zn-O Thin-Film Transistors

Jung, Joohye,Kim, Si Joon,Jung, Tae Soo,Na, Jaewon,Yoon, Doo Hyun,Sabri, Mardhiah Muhamad,Kim, Hyun Jae Institute of Electrical and Electronics Engineers 2017 IEEE transactions on electron devices Vol.64 No.2

<P>We investigated a novel deoxyribonucleic acid (DNA) sensing system based on low-temperature solution-processed In-Zn-O (IZO) thin-film transistors (TFTs) suggesting an alternative evolutionary line to the traditional DNA biosensors. The IZO TFTs exhibited a favorable microenvironment for adsorbed biomolecule such as DNA to transfer electron, which emerges potential sensing behavior. Superior sensing ability to detect and distinguish 0.45 mu L of 0.1 mu M of target DNA oligomers was secured, and indeed selectivity based on oxidation potentials of each oligomer was achieved. Our IZO TFT had a turn-on voltage (V (ON)) of -1.2 V, on/off ratio of 3.55 x 10(6), and on-current (I (ON)) value of 9.02 mu A in pristine condition. A dry-wet method was applied to immobilize target DNA oligomers on the IZO surface, after which we observed a negative shift of the transfer curve accompanied by a significant increase in the I (ON) and the degradation of the V ON and ON/OFF ratio. Furthermore, the variances in these parameters became increasingly severe following the concentration of target DNA. In addition, the sensing mechanism, oxidation of DNA that had been figured out in our previous research offered selectivity in different types of oligomer based on their capabilities to be oxidized; our biosensors were more sensitive to guanine and cytosine compared with adenine. The biosensor applied on a flexible substrate under the same fabrication conditions obtained exactly analogous sensing behavior. These results suggest a prominent candidate to conventional biosensor area and also its posterior applications by demonstrating remarkable sensitivity, selectivity, and feasibility of flexible device.</P>

SnSe₂ nanoplate–graphene composites as anode materials for lithium ion batteries

Choi, Jaewon,Jin, Jaewon,Jung, Il Gu,Kim, Jung Min,Kim, Hae Jin,Son, Seung Uk Royal Society of Chemistry 2011 Chemical communications Vol.47 No.18

<P>Through a solution approach, SnSe<SUB>2</SUB> nanoplate–graphene composites were prepared and applied as anode materials in lithium ion batteries, showing promising storage performance superior to SnSe<SUB>2</SUB> nanoplates or graphene alone.</P> <P>Graphic Abstract</P><P>Through a solution approach, SnSe<SUB>2</SUB> nanoplate–graphene composites were prepared and applied as anode materials in lithium ion batteries, showing promising storage performance superior to SnSe<SUB>2</SUB> nanoplates or graphene alone. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1cc10317b'> </P>

Helical rib의 각도 변화에 따른 원통형 복합재 격자 구조물의 좌굴 해석

정재원(Jaewon Jung),김평화(Pyunghwa Kim),박정선(Jungsun Park) 항공우주시스템공학회 2019 항공우주시스템공학회 학술대회 발표집 Vol.2019 No.11

국내 하천수의 수열에너지 활용 가능성 분석

정재원(Jaewon Jung),남지수(Jisu Nam),정성은(Sungeun Jung),김정욱(Jungwook Kim),김형수(Hung Soo Kim) 한국신재생에너지학회 2018 신재생에너지 Vol.14 No.4

In recent years, there has been continued interest in the utilization of river discharge as a new energy source. Before this can be achieved, it is essential to examine the stability of the flow rate. In Korea, however, there are no guidelines for calculating the water availability of river water. Therefore, this paper proposes a method of estimating the water availability of river water based on the permissible standard flow rate according to the permission system of river water in Korea, and the amount of domestic river water available is estimated. In addition, the area where sufficient hydrothermal energy can be taken is analyzed considering the heat pump installation conditions of the river water. These results can be utilized as an indicator for evaluating river water hydrothermal energy as an alternative to fossil fuels and the contribution of river water to greenhouse gas reduction.

해성Ⅰ의 공기흡입식 엔진 성능 검증을 위한 지상시험평가

정재원(Jaewon Jung),김종진(Jongjin Kim),박상우(Sangwoo Park),김상용(Sangyong Kim),김무곤(Moogon Kim),김태훈(Taehoon Kim) 한국추진공학회 2009 한국추진공학회 학술대회논문집 Vol.2009 No.5

해성Ⅰ에 사용되는 공기흡입식 엔진은 초기 발사추력을 제공하는 부스터가 분리된 후 목표물까지 비행할 수 있는 2차 추진기관이다. 유도탄이 비행을 하는 동안 이동방향 및 고도를 원하는 대로 제어하기 위해서는 체계종합에서의 엔진 성능 검증이 필수적이며, 이를 위해 비행시험 전 지상에서 유도탄 체계의 엔진시동시험을 수행하여야 한다. 본 논문은 해성Ⅰ에 사용되는 공기흡입식 엔진의 성능검증을 위한 지상 시험, 평가 방법을 제시한다. The Air-breathing engine like Sea-StarⅠ is a second propulsive force generator to fly to the target after the booster generating initial propulsive force is separated. The performance of Sea-StarⅠ engine should be verified because the cruise missile controls direction and altitude during flight, so ground engine test is executed before flight test. This these presents evaluation method of ground engine test to verify performance of Sea-StarⅠ"s engine.