Xanthogranulomatous inflammation of the lower jaw bone: a rare case report

Hyesung Bae,Kil-Hwa Yoo,Min-Seok Oh 대한구강악안면외과학회 2023 대한구강악안면외과학회지 Vol.49 No.6

Xanthogranulomatous inflammation (XGI) is an uncommon type of chronic inflammation and is histologically characterized by foamy histiocytes and giant cells. The most common sites of occurrence are kidneys and gallbladder. The etiology remains controversial. Involvement of the lower jaw bone is rare. In this study, we report a case of XGI presenting in the lower jaw.

Evaluation of forecasting methods in aggregate production planning: A Cumulative Absolute Forecast Error (CAFE)

Ha, Chunghun,Seok, Hyesung,Ok, Changsoo Elsevier 2018 COMPUTERS & INDUSTRIAL ENGINEERING Vol.118 No.-

<P><B>Abstract</B></P> <P>The purpose of forecasting error measures is to estimate forecasting methods and choose the best one. Most typical forecasting error measures are designed based on the gap between forecasts and actual demands and, consequently, a forecasting method yielding forecasts in accordance with real demands is considered as good. However, in some applications such as aggregate production planning, these measures are not suitable because they are not capable for considering any effects caused by forecasting error such as increasing cost or decreasing profit. To tackle this issue, we propose a new measure, CAFE (Cumulative Absolute Forecast Error), to evaluate forecasting methods in terms of total cost. Basically, the CAFE is designed to consider not only forecasting errors but also costs occured by errors in aggregate production planning which is set up based on forecasts. The CAFE is a product sum of cumulative forecasting error and weight factors for backorder and inventory costs. We have demonstrated the effectiveness of the proposed measure by conducting intensive experiments with demand data sets from M3-competition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new measure for forecasting error is designed to consider the cost which the error causes. </LI> <LI> The proposed measure enables to calculate the real effect of forecasting error. </LI> <LI> Extensive experiments with datasets from M3 competition. </LI> </UL> </P>

죽음의 계곡 벤처기업 비즈니스 프로세스 개발

황은석(Eunseok Hwang),석혜성(Hyesung Seok),정광헌(Kwanghun Chung) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.3

2017년 청년 실업률이 역대 최고치를 기록한 가운데, 본 상황을 타파하기 위한 대안으로 창업 활성화가 떠오르고 있다. 벤처 기업 수 및 신규 벤처 투자 금액은 매년 역대 치를 갱신하고 있으며 정부에서는 중소기업청을 중소벤처기업부로 격상시켰다. 문제는 스타트업의 성공률이 높지 않다는 데 있다. 한국 신생기업 생존율은 최근 3년 39.1%에 불과하며, 죽음의 계곡(Valley of Death) 단계에서 90%에 달하는 기업들이 실패하고 있다. 초기 스타트업은 죽음의 계곡을 넘어갈 수 있느냐가 관건이며 이를 위해투자가 어느 정도 규모와 적시성을 가지고 이루어지느냐가 중요한 변수로작용한다. 하지만, 현재 스타트업의 비즈니스 모델을 정립하기 위한 모델들은 투자 시 실질적인 기업 평가 변수가 반영되어 있지 않아 투자 유치에 어려움이 있다. 본 논문에서는 주요 투자 주체인 엔젤투자기관 및 벤처캐피탈이 투자를 위해 중점적으로 고려하는 변수 및 비즈니스 모델이 혼합된 프로세스를 개발했다. 또한, 새로 개발한 Death Valley Venture(DVV) 비즈니스 프로세스를 기존의 기법들과 비교하고, 적용 사례를 제시하였다. Youth unemployment reached a record high in 2017, and business revitalization is emerging as a means of overcoming this situation. The number of venture companies and amounts of new venture investments are increasing year on year, and the government has upgraded Small and Medium Business Administration to the Ministry of SMEs and Startups. However, the success rate of startups is relatively poor. Over the past three years only 39.1% of Korean startups survived and 90% of companies failed in the Valley of Death phase. Survival this phase is critical for early startups, and thus, the amount and timing of investments are critical. Current models for establishing business startups do not effectively attract investments because they lack practical, corporate evaluation variables. In this paper, we develop a mixed process that incorporates the factors and business models focused on by venture capital investors. In addition, we compared our Death Valley Venture (DVV) process with current methods and provide an example of its application.

Fairness-based Bidding Model for Renewable Portfolio Standard Policy in South Korea Standard Policy in South Korea

Kim Youngdong,Kim Kyungdoh,Seok Hyesung 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.4

The share of renewable energy has already exceeded that of nuclear power in the United Kindom, Germany (by 30%), and Japan (10%), whereas the supply of alternative energy in South Korea is significantly less than that of advanced countries. In 2011, South Korea ended the feed-in-tariff operation and implemented renewable portfolio standards (RPSs), which require producers or sellers of electricity to supply a specified percentage of electricity generated or sold from renewable energy sources. Each operator receives renewable energy certificates corresponding to the amount of electricity supplied from renewable energy sources, allowing them to sell excess electricity or buy electricity to manage a deficit. Although the RPS ensures fairness by specifying separate quantities that can be sold based on each operator’s capacity, it focuses more on effectiveness. In this study, RPSs are investigated from the perspectives of effectiveness and fairness, and a new bidding model that further considers fairness is developed.

RTP-Based Residential Energy Consumption Scheduling Model with an Energy Storage System as an Independent Provider

Kim Sehwan,Ok Changsoo,Seok Hyesung 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

Various real-time pricing (RTP)-based residential consumption scheduling models have been developed to deal with the blackout problem and supply electricity more stably. However, most RTP-based models cause a rebound peak problem. Hence, we propose an innovative RTP-based model with an energy storage system (ESS) as an independent power provider, which is a more reliable and practical solution (called RTP with ESS in this study) than previous models. The price competition between the ESS power provider and wholesale market reduces the power consumption cost of the consumer and peak load of the supply. We compared three models: (1) Non-scheduling, (2) RTP-based Scheduling, and (3) RTP with ESS Scheduling models. Test results reveal that the RTP with ESS Scheduling model reduced consumer power usage costs by 35.24% and 25.86% more than the two models above, respectively. In addition, the RTP with ESS Scheduling model reduced the peak-to-average power ratio of power consumption by 35.10% and 8.71% more than those of the non-scheduling and the existing RTP models, respectively. The consumer standard deviation of power consumption cost was 25.70% and 49.25% lower than those of the non-scheduling and existing RTP models, respectively, and had a fair distribution of power usage costs

Multifaceted Role of a Dibutylhydroxytoluene Processing Additive in Enhancing the Efficiency and Stability of Planar Perovskite Solar Cells

Kumar, Sujit,Choi, Yunseong,Kang, So-Huei,Oh, Nam Khen,Lee, Junghyun,Seo, Jihyung,Jeong, Mingyu,Kwon, Hyoung Woo,Seok, Sang Il,Yang, Changduk,Park, Hyesung American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.42

<P>Significant research efforts are currently being devoted to improving both the crystalline quality and stability of lead halide perovskite absorbers to advance the commercial prospects of perovskite-based solar cells. Herein, we report a simple one-step dibutylhydroxytoluene (BHT) additive-based approach for simultaneously improving the crystallinity and resistance of perovskite films under adverse degradation conditions. We found that BHT, commonly known for its antioxidant properties, can considerably improve the performance of methylammonium lead iodide perovskite solar cells by modulating the chemical environment within the precursor medium to form intermediate complexes, and it can also suppress photooxidation, which results in perovskite degradation under environmental operating conditions. Consequently, a device exhibited a significant power conversion efficiency improvement to 18.1% with the BHT-additive-based perovskite absorber, exceeding the 17.1% efficiency achieved for the control device. The BHT additive also improved the perovskite stability by quenching intermediate reactions resulting in perovskite degradation to an undesirable lead iodide phase, as evidenced by detailed analysis of absorption spectra, grazing-incidence wide-angle X-ray scattering, X-ray photoelectron spectra, and photoluminescence measurements.</P> [FIG OMISSION]</BR>

Most facile synthesis of Zn-Al:LDHs nanosheets at room temperature via environmentally friendly process and their high power generation by flexoelectricity

Choi, Min-Ju,Eom, Ji-Ho,Shin, Sung-Ho,Nah, Junghyo,Choi, Jin-Seok,Song, Hyun-A.,An, Hyesung,Kim, Hyun You,Pammi, S.V.N.,Choi, Goeun,Choy, Jin-Ho,Swathi, Ippili,Jella, Venkatraju,Park, Byeong-Ju,Choi, ELSEVIER SCIENCE B.V. AMSTERDAM 2018 Materials today energy Vol.2018 No.10

얼굴인식 기술을 통한 온라인 시험 부정행위 방지 시스템 설계

김병운(Byeongun Kim),김수현(Suhyeon Kim),박종봉(Jongbong Park),한승태(Seungtae Han),석혜성(Hyesung Seok) 대한산업공학회 2016 대한산업공학회 추계학술대회논문집 Vol.2016 No.11

본 논문에서는 얼굴인식 기술을 통한 온라인 시험 부정행위 방지 시스템을 제안한다. 제안된 시스템의 특징은 다음과 같다. 첫째, 이 시스템은 온라인 시험 도중 발생하는 가장 치명적이며 원초적인 부정행위를 방법을 방지하는 형식을 지니고 있다. 둘째, 이 프로젝트의 목표는 온라인 강의 시험의 부정행위 비율을 줄이는 것에 있다. 셋째, 이 시스템은 온라인 시험 시 부정행위를 줄일 수 있는 잠재성을 가지고 있고, 다양한 온라인 가의 시험에 사용될 수 있다. 제안된 시스템의 성능평가 결과 일정 수준 이상의 부정행위 시도를 잡아낼 수 있는 우수한 성능을 보여주었다. In this paper, we propose an online exam cheating prevention system based on facial recognition technology. Features of the proposed system are as follows. First, this system has the format, how to prevent the most fatal and primitive cheating that occurs during online exams. Second, the goal of this project is cheating on reducing the proportion of online teaching test Thirds, this system has the potential to reduce cheating during online exam, it can be used to test a variety of online courses. Performance evaluation of the proposed system, results showed an excellent performance to catch a certain level or more cheating attempts.