• Title/Summary/Keyword: Tae-yong Jeon

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Air Handling Unit Utilizing Water/Air Direct Contact Heat Exchanger with Mesh (공기조화기내 메쉬삽입 물-공기 직접접촉의 열전달 특성 연구)

  • Jeon, Yong-Han;Kim, Jong-Yoon;Kim, Nam-Jin;Seo, Tae-Boem;Kim, Chong-Bo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.1
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    • pp.75-80
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    • 2008
  • The objective of this research was to investigate the enhancement of heat transfer by mesh in water/air direct contact air conditioning system. Mesh is inserted as a turbulent promoter in front of the water injection nozzle. The heat transfer characteristics with and without mesh and the effect of the number of inserted mesh and mesh porosity size have been studied experimentally. Inserted mesh improves heat transfer efficiency compared to non~inserted mesh system and heat transfer efficiency increased as the number of mesh is increased. Meanwhile, heat transfer efficiency decreased as the porosity of the mesh is increased. With inserted mesh, inlet and outlet temperature difference of air increased more than 50%. Heat exchange time of water/air to reach the 100% humidity decreased less than 30%. This result shows inserted mesh can enhance the performance of the water/air direct contact air conditioning system.

Magnetic Properties and Microstructure of Nanocrystalline NdFeB Magnets Fabricated by a Modified Hot Working Process

  • Kim, Hyoung-Tae;Kim, Yoon-Bae;Jeon, Woo-Yong;Kim, Hak-Shin
    • Journal of Magnetics
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    • v.7 no.4
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    • pp.138-142
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    • 2002
  • Magnetic properties, microstructure and texture of NdFeB magnets fabricated by a modified hot working process from commercial melt-spun powders (Magnequench; MQPA, MQPB and MQPB+) have been investigated. The hot-pressed isotropic magnet made from MQPA powder, which contains higher Nd content than that of MQPB or MQPB+, shows higher coercivity. The magnet also shows homogenous and fine grains with higher coercivity for higher consolidation pressure. The hot-deformed MQPA magnet shows a strong anisotropy along the press direction with homogeneous platelet Nd$_2$Fe$_{14}$B grains of 50∼100nm in thickness and 200∼500nm in length. The hot-deformed MQPB+ magnet, however, shows low remanence and low coercivity. The microstructure of the magnet consists of two areas; undeformed Nd$_2$Fe$_{14}$B grains and well-aligned but large grains with 3∼4 $\mu$m in length. Low Nd content attributes to the formation of the two different area.

A Study on the Economic Analysis of ESS (ESS의 경제성 분석기법에 관한 연구)

  • Yoon, Young-Sang;Jeon, Weon-Young;Shin, Yong-Tae;Kim, Jong-Bae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.679-681
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    • 2014
  • 에너지저장시스템(Energy Stroage System, ESS)은 잉여 전력과 에너지를 필요한 시점에 적절하게 공급할 수 있도록 에너지를 저장해두는 기술로 전기에너지의 픔질 및 효율성을 극대할 수 있는 에너지 활용 시스템이다. 미국을 비롯한 유럽 선진국들은 다양한 ESS 관련 제도정비 및 개선을 통해 ESS 산업의 활성화를 유도하고 있다. 우리나라의 경우, 신재생에너지 확대 정책을 수립하고 에너지 저장기술을 그린에너지 분야의 주요 핵심과제 선정하여 체계적인 육성전략을 추진 중에 있다. 그러나, ESS 도입 및 활성화를 위한 법제도적 기반이 마련되어 있지 않고, ESS도입에 대한 경제적 효과성에 대한 객관적인 기준이 없어, ESS의 보급 및 활성화가 제대로 이루어지지 않고 있는 실정이다. 본 연구에서는, ESS의 보급과 활성화를 위해 효과적으로 ESS의 경제성 분석하기 위한 기법을 제시하는 것을 목적으로 한다. 세부적으로는 전기요금 산정방식에 따라 ESS의 운영모형을 정의하고, 운영모형별 경제성을 분석하기 위한 기법을 제시한다. 그리고, 실제 데이터를 활용하여 ESS로 절감할 수 있는 피크 크기를 구할 수 있는 알고리즘을 구현한다. 또한, 저감 피크와 온도, 습도에 대한 회귀 분석을 통하여 최대저감피크를 예측할 수 있는 해법을 제시한다.

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Improvement of PM10 Forecasting Performance using Membership Function and DNN (멤버십 함수와 DNN을 이용한 PM10 예보 성능의 향상)

  • Yu, Suk Hyun;Jeon, Young Tae;Kwon, Hee Yong
    • Journal of Korea Multimedia Society
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    • v.22 no.9
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    • pp.1069-1079
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    • 2019
  • In this study, we developed a $PM_{10}$ forecasting model using DNN and Membership Function, and improved the forecasting performance. The model predicts the $PM_{10}$ concentrations of the next 3 days in the Seoul area by using the weather and air quality observation data and forecast data. The best model(RM14)'s accuracy (82%, 76%, 69%) and false alarm rate(FAR:14%,33%,44%) are good. Probability of detection (POD: 79%, 50%, 53%), however, are not good performance. These are due to the lack of training data for high concentration $PM_{10}$ compared to low concentration. In addition, the model dose not reflect seasonal factors closely related to the generation of high concentration $PM_{10}$. To improve this, we propose Julian date membership function as inputs of the $PM_{10}$ forecasting model. The function express a given date in 12 factors to reflect seasonal characteristics closely related to high concentration $PM_{10}$. As a result, the accuracy (79%, 70%, 66%) and FAR (24%, 48%, 46%) are slightly reduced in performance, but the POD (79%, 75%, 71%) are up to 25% improved compared with those of the RM14 model. Hence, this shows that the proposed Julian forecast model is effective for high concentration $PM_{10}$ forecasts.

Initial report of extraperitoneal pedicle dissection in deep inferior epigastric perforator flap breast reconstruction using the da Vinci SP

  • Jung, Ji Hyuk;Jeon, Yeo Reum;Lee, Dong Won;Park, Hyung Seok;Lew, Dae Hyun;Roh, Tae Suk;Song, Seung Yong
    • Archives of Plastic Surgery
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    • v.49 no.1
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    • pp.34-38
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    • 2022
  • The deep inferior epigastric perforator (DIEP) flap has been widely used for autologous breast reconstruction after mastectomy. In the conventional surgical method, a long incision is needed at the anterior fascia of the rectus abdominis muscle to obtain sufficient pedicle length; this may increase the risk of incisional hernia. To shorten the incision, several trials have investigated the use of endoscopic/robotic devices for pedicle harvest; however, making multiple additional incisions for port insertion and operating in the intraperitoneal field were inevitable. Here, we describe the first case, in which a DIEP free flap was successfully made using the da Vinci SP model. Our findings can help surgeons perform operations in smaller fields with a single port in the extraperitoneal space. Moreover, this method is expected to lead to fewer donor-related complications and faster healing.

Non-epitheliotropic Cutaneous T-cell lymphoma in a cat: a case report

  • Jeon, YeSeul;Bae, Hyeona;Shin, Sun Woo;Cho, ARom;Kim, Young Ju;Hwang, Tae Sung;Lee, Hee Chun;Hyun, Jae-Eun;Cho, Kyu-Woan;Jung, Dong-In;Kim, Dae-Yong;Yu, DoHyeon
    • Korean Journal of Veterinary Research
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    • v.62 no.2
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    • pp.13.1-13.5
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    • 2022
  • Cutaneous lymphoma is rare in cats. An 11-year-old spayed female Persian cat presented with crust, ulceration, and multiple nodules on the shoulder and forelimb for 2 months. Computed tomography revealed a diffuse, irregularly margined lesion in the dorsal cutis extending from cervical to thoracic vertebrae. Cytological evaluation predominantly revealed large round cells with multilobulated nuclei and basophilic cytoplasm. Histopathological examination confirmed round CD3+/PAX5-cells packed in the dermis. Thus, the diagnosis of non-epitheliotropic cutaneous lymphoma with a diffuse large T-cell type was made. The disease progressed rapidly for the next 2 weeks, and the owner elected humane euthanasia.

Role of extrinsic physical cues in cancer progression

  • Ok-Hyeon Kim;Tae Jin Jeon;Yong Kyoo Shin;Hyun Jung Lee
    • BMB Reports
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    • v.56 no.5
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    • pp.287-295
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    • 2023
  • The tumor microenvironment (TME) is a complex system composed of many cell types and an extracellular matrix (ECM). During tumorigenesis, cancer cells constantly interact with cellular components, biochemical cues, and the ECM in the TME, all of which make the environment favorable for cancer growth. Emerging evidence has revealed the importance of substrate elasticity and biomechanical forces in tumor progression and metastasis. However, the mechanisms underlying the cell response to mechanical signals-such as extrinsic mechanical forces and forces generated within the TME-are still relatively unknown. Moreover, having a deeper understanding of the mechanisms by which cancer cells sense mechanical forces and transmit signals to the cytoplasm would substantially help develop effective strategies for cancer treatment. This review provides an overview of biomechanical forces in the TME and the intracellular signaling pathways activated by mechanical cues as well as highlights the role of mechanotransductive pathways through mechanosensors that detect the altering biomechanical forces in the TME.

A Study on State Analysis of Substation Using PMU (PMU를 이용한 변전소 상태 해석에 관한 연구)

  • Tae-Hee Kim;Kyung-Min Lee;Cheol-Won Park;Dong-Hoon Jeon;Dae-Yoon Kwon;Yong-Sung Choi
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.3
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    • pp.304-308
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    • 2024
  • In this paper, in order to analyze the PMU data of the accident section, we collected the raw data of a total of 35 PMU installed at the Yeonggwang substation and tried to find a way to analyze the data, and analyzed the data using Excel format and formula. As a result, the three-phase voltage and current data of the PMU were calculated using formulas in Excel and interpreted as effective and reactive power, and it was possible to check the effective and reactive power of the accident section through the graph to see why it was different from before the accident. As a result, it was confirmed that each power was greatly reduced in the graph of the effective and reactive power of the accident section, and it was confirmed that the loss occurred as the power of the accident section was greatly reduced.

Artificial Intelligence Plant Doctor: Plant Disease Diagnosis Using GPT4-vision

  • Yoeguang Hue;Jea Hyeoung Kim;Gang Lee;Byungheon Choi;Hyun Sim;Jongbum Jeon;Mun-Il Ahn;Yong Kyu Han;Ki-Tae Kim
    • Research in Plant Disease
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    • v.30 no.1
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    • pp.99-102
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    • 2024
  • Integrated pest management is essential for controlling plant diseases that reduce crop yields. Rapid diagnosis is crucial for effective management in the event of an outbreak to identify the cause and minimize damage. Diagnosis methods range from indirect visual observation, which can be subjective and inaccurate, to machine learning and deep learning predictions that may suffer from biased data. Direct molecular-based methods, while accurate, are complex and time-consuming. However, the development of large multimodal models, like GPT-4, combines image recognition with natural language processing for more accurate diagnostic information. This study introduces GPT-4-based system for diagnosing plant diseases utilizing a detailed knowledge base with 1,420 host plants, 2,462 pathogens, and 37,467 pesticide instances from the official plant disease and pesticide registries of Korea. The AI plant doctor offers interactive advice on diagnosis, control methods, and pesticide use for diseases in Korea and is accessible at https://pdoc.scnu.ac.kr/.

Small Black Soybean (Glycine max Merr.) Inhibits Mast Cell-mediated Allergic Reaction and Inflammatory Cytokine Secretion

  • Shin, Hye-Young;Lim, Jong-Pil;Kim, Dae-Keun;Chae, Byeong-Suk;Kwon, Young-Ee;Oh, Chan-Ho;Cho, Moon-Gu;Lee, Tae-Kyoo;Park, Jeong-Suk;Lee, Jae-Hyeok;Jeon, Hoon;Shin, Tae-Yong
    • Natural Product Sciences
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    • v.13 no.3
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    • pp.263-267
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    • 2007
  • The mast cell-mediated immediate-type allergic reaction is involved in many allergic diseases such as asthma, allergic rhinitis, and sinusitis. The discovery of drugs for the treatment of mast cell-mediated immediate-type allergic diseases is a very important subject in human health. In this study, we investigated the effect of small black soybean (Glycine max Merr.) (Leguminosae) on mast cell-mediated allergic reaction and pro-inflammatory cytokine secretion. Small black soybean (SBS) inhibited compound 48/80-induced systemic reaction. SBS attenuated immunoglobulin (Ig) E-mediated local allergic reaction. In addition, SBS decreased the phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated tumor necrosis factor $(TNF)-{\alpha}$ and interleukin (IL)-8 secretion in human mast cells. These results indicate that SBS may be beneficial in the treatment of mast cell-mediated immediate-type allergic reactions.