• Title/Summary/Keyword: Oh Gyu-won

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A review of 3D printing technology for piezoresistive strain/loadcell sensors (3D 프린팅 센서 연구 동향 소개-전왜성 변형/로드셀 센서 중심으로)

  • Cho, Jeong Hun;Moon, Raymond Hyun Woo;Kim, Sung Yong;Choi, Baek Gyu;Oh, Gwang Won;Joung, Kwan Young;Kang, In Pil
    • Journal of Sensor Science and Technology
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    • v.30 no.6
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    • pp.388-394
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    • 2021
  • The conventional microelectromechanical system (MEMS) process has been used to fabricate sensors with high costs and high-volume productions. Emerging 3D printing can utilize various materials and quickly fabricate a product using low-cost equipment rather than traditional manufacturing processes. 3D printing also can produce the sensor using various materials and design its sensing structure with freely optimized shapes. Hence, 3D printing is expected to be a new technology that can produce sensors on-site and respond to on-demand demand by combining it with open platform technology. Therefore, this paper reviews three standard 3D printing technologies, such as Fused Deposition Modeling (FDM), Direct Ink Writing (DIW), and Digital Light Processing (DLP), which can apply to the sensor fabrication process. The review focuses on strain/load sensors having both sensing material features and structural features as well. NCPC (Nano Carbon Piezoresistive Composite) is also introduced as a promising 3D material due to its favorable sensing characteristics.

Improvement of Heat Resistant of Adhesion between m-Aramid Sheet and Metal Materials using Epoxy/Phenolic Resin (Epoxy/Phenolic resin을 활용한 메타-아라미드 시트지와 금속 소재의 내열접착성 향상)

  • Kang, Chan Gyu;Chae, Ju Won;Choi, Seung Jin;Lee, Ji Su;Kim, Sam Soo;Lee, Sang Oh;Lee, Jaewoong
    • Textile Coloration and Finishing
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    • v.34 no.3
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    • pp.157-164
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    • 2022
  • This study tried to analyze the heat resistance properties by blending epoxy and phenolic resin in a certain ratio, and to analyze the adhesive properties at the time of metal-polymer hetero-adhesion by applying Epoxy-phenolic resin between a silicon steel sheet and m-aramid sheet, the viscosity, adhesive peel strength, and adhesive cross section were measured using a rotational rheometer, a tensile tester(UTM), and a field emission scanning electron microscopy(FE-SEM). The thermal stability and heat resistance were confirmed by measuring the mass loss according to the temperature increase using Thermogravimetric analysis(TGA). After blending with epoxy and Phenolic resin(1:0.25 ratio) curing at 110℃ for 10 min, high adhesive strength was improved more than 40% compared to the adhesive strength using epoxy alone. When the space between the silicon steel sheet and m-aramid sheet, which is created during curing of the E-P blend, is cured with a slight weight, it is possible to control the empty space and improve adhesion.

Synergistic antibacterial effect of disinfectants and microbubble water to Salmonella Typhimurium

  • Seung-Won, Yi;Young-Hun, Jung;Sang-Ik, Oh;Han Gyu, Lee;Yoon Jung, Do;Eun-Yeong, Bok;Tai-Young, Hur;Eunju, Kim
    • Korean Journal of Veterinary Service
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    • v.45 no.4
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    • pp.277-284
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    • 2022
  • Salmonella is a pathogenic bacterium that has long been important industrially because it has a wide host range and can be transmitted to humans through direct contact as well as indirect contact such as food contaminated with animal waste. Understanding how to reduce Salmonella contamination in pig farms is important for public health and the livestock industry from an economic perspective. In the swine industry, high concentrations of disinfectants have been applied because it is difficult to effectively control Salmonella in environments contaminated with organic substances. In order to evaluate the synergetic effect of disinfectants, the efficacy of two commercial disinfectants diluted in hard water and microbubble water (MBW) were compared under the laboratory condition. Different concentrations of both disinfectants combined with 1% detergent diluted in the two diluents were evaluated for their antibacterial effect. In the case of monopersulfate-based disinfectant groups, the growth of Salmonella was not observed at 1:200 dilution with both the hard water and MBW combined with 1% detergent. In the case of citric acid-based disinfectant, the bacterial growth was not observed at 1:800 dilution with MBW combined with 1% detergent. Our results show that the use of MBW as a diluent might improve the biological activities of acid-based disinfectant.

Influence of the Vibration Exposure on Shoulder and Back Extensor Muscles Activity During Forward-head and Over-head Task

  • Cheon-jun Park;Duk-hyun An;Jae-seop Oh;Won-gyu Yoo
    • Physical Therapy Korea
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    • v.30 no.1
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    • pp.23-31
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    • 2023
  • Background: Several factors contribute to shoulder pain, including abnormal neck posture, repeated use of the upper limbs, work involving raising the upper limbs above the head, and the effects of vibration. However, previous study has reported that constant vibration exposure could impact improvement of the stability on joints related with muscle recruitment and activation. For this difference reason, we need to verify for the complex study of relationship with repetitive upper limb movements, poor head posture, and constant vibration exposure. Objects: Our study was made to investigate the influence of vibration exposure on the shoulder muscle activity during forward-head and over-head tasks with isometric shoulder flexion. Methods: In a total of 22 healthy subjects, surface electromyography (EMG) data were collected from shoulder muscles (upper/lower trapezius, serratus anterior, and lumbar erector spinae) on tasks (neutral-head task [NHT], forward-head task [FHT], and over-head task [OHT]) with and without vibration exposure. Results: In all tasks, the EMG data of the upper trapezius and serratus anterior significantly increased with vibration exposure (p < 0.05). Furthermore, the EMG data of the lumbar erector spinae significantly increased with vibration exposure in the NHT and FHT (p < 0.05). Conclusion: We suggest that continuous vibration exposure during the use of hand-held tools in the tasks could be associated with harmful effects in the workplace. Lastly, we clinically need to examine the guidelines regarding the optimal posture and vibration exposure.

Single-cell RNA sequencing identifies distinct transcriptomic signatures between PMA/ionomycin- and αCD3/αCD28-activated primary human T cells

  • Jung Ho Lee;Brian H Lee;Soyoung Jeong;Christine Suh-Yun Joh;Hyo Jeong Nam;Hyun Seung Choi;Henry Sserwadda;Ji Won Oh;Chung-Gyu Park;Seon-Pil Jin;Hyun Je Kim
    • Genomics & Informatics
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    • v.21 no.2
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    • pp.18.1-18.11
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    • 2023
  • Immunologists have activated T cells in vitro using various stimulation methods, including phorbol myristate acetate (PMA)/ionomycin and αCD3/αCD28 agonistic antibodies. PMA stimulates protein kinase C, activating nuclear factor-κB, and ionomycin increases intracellular calcium levels, resulting in activation of nuclear factor of activated T cell. In contrast, αCD3/αCD28 agonistic antibodies activate T cells through ZAP-70, which phosphorylates linker for activation of T cell and SH2-domain-containing leukocyte protein of 76 kD. However, despite the use of these two different in vitro T cell activation methods for decades, the differential effects of chemical-based and antibody-based activation of primary human T cells have not yet been comprehensively described. Using single-cell RNA sequencing (scRNA-seq) technologies to analyze gene expression unbiasedly at the single-cell level, we compared the transcriptomic profiles of the non-physiological and physiological activation methods on human peripheral blood mononuclear cell-derived T cells from four independent donors. Remarkable transcriptomic differences in the expression of cytokines and their respective receptors were identified. We also identified activated CD4 T cell subsets (CD55+) enriched specifically by PMA/ionomycin activation. We believe this activated human T cell transcriptome atlas derived from two different activation methods will enhance our understanding, highlight the optimal use of these two in vitro T cell activation assays, and be applied as a reference standard when analyzing activated specific disease-originated T cells through scRNA-seq.

A retrospective study of age-specific disease incidence in major popular breed dogs in Republic of Korea

  • Seung-Won Yi;Sang-Ik Oh;Yoon Jung Do;Jae Gyu Yoo;Eunju Kim
    • Korean Journal of Veterinary Research
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    • v.63 no.4
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    • pp.34.1-34.9
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    • 2023
  • Dogs exhibit patterns of health issues that vary by life stage. An understanding of disease incidence with respect to breed and age/life stage could be an important component of canine health management and welfare. This study aimed to describe the age-specific disease incidence of 3 small dog breeds that attended veterinary clinics in the Republic of Korea, based on data from electronic veterinary medical records (EVMRs). A total of 40,785 EVMRs from Maltese (n = 21,355), Miniature Poodle (n = 11,658) and Shih Tzu dogs (n = 7,772) were analyzed. Common health problems in 3 small dog breeds were 'diseases of the skin' and 'diseases of the ear,' respectively. Among dogs aged ≤ 3 years, 'preventive medicine' was the most common cause cited for veterinary clinic visits. Among dogs aged 4 to 8 years, the most frequent health problems were 'diseases of the skin.' Among dogs aged 9 to 13 years, 'heart diseases,' 'kidney diseases,' 'mammary gland tumor,' and 'neoplasia (unspecified)' were considerably more frequent, compared to the rates in dogs ≤3 years. Among dogs aged ≥ 14 years, 'heart diseases' and 'sneezing/cough' were the main health problems. In all breeds, the frequencies of 'diseases of circulatory system,' 'diseases of respiratory system,' 'diseases of the nervous system,' 'endocrine' and 'neoplasia' increased rapidly with aging. This surveillance could inform strategies for disease screening tests and management based on life stage in these dog breeds and enable more effective health management.

Design of an Integrated Monitoring System for Constructional Structures Based on Mobile Cloud in Traditional Towns with Local Heritage

  • Min, Byung-Won;Oh, Sang-Hoon;Oh, Yong-Sun;Okazaki, Yasuhisa;Yoo, Jae-Soo;Park, Sun-Gyu;Noh, Hwang-Woo
    • International Journal of Contents
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    • v.11 no.2
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    • pp.37-49
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    • 2015
  • Sensors, equipment, ICT facilities and their corresponding software have a relatively short lifetime relative to that of constructional structure, so these devices have to be continuously fixed or exchanged during maintenance and management. Furthermore, software or analysis tools should be periodically upgraded according to advances in ICT and analysis technology. Conventional monitoring systems have serious problems in that it is difficult for site engineers to modify or upgrade hardware and analysis algorithms. Moreover, we depend on the original system developer when we want to modify or upgrade inner program structures. In this paper, we propose a novel design for integrated maintenance and management of a monitoring system by applying the mobile cloud concept. The system is intended for use in disaster prevention of constructional structures, including bridges, tunnels, and in traditional buildings in a local heritage village, we analyze the status of these structures over a long term or a short-term period as well as in disaster situations. Data are collected over a mobile cloud and future expectations are analyzed according to probabilistic and statistical techniques. We implement our integrated monitoring system to solve the existing problems mentioned above. The final goal of this study is to design and implement a monitoring system for more than 10,000 structures spread within Korea. Furthermore, we can specifically apply the monitoring system presented here to a bridge made from timber in Asan Oeam Village and a traditional house in Andong Hahoe Village to monitor for possible disasters. The entire system design and implementation can be developed on the LinkSaaS platform and the monitoring services can also be implemented on the platform. We prove that the proposed system has good performance by performing a TTA authentication test, web accommodation test, and operation test using emulated data.

Spatial Optical Modulator (SOM);Samsung's Light Modulator for the Next Generation Laser Display

  • Yun, Sang-Kyeong;Song, Jong-Hyeong;Lee, Tae-Won;Yeo, In-Jae;Choi, Yoon-Joon;Lee, Yeong-Gyu;An, Seung-Do;Han, Kyu-Bum;Victor, Yurlov;Park, Heung-Woo;Park, Chang-Su;Kim, Hee-Yeoun;Yang, Jeong-Suong;Cheong, Jong-Pil;Ryu, Seung-Won;Oh, Kwan-Young;Yang, Haeng-Seok;Hong, Yoon-Shik;Hong, Seok-Kee;Yoon, Sang-Kee;Jang, Jae-Wook;Kyoung, Je-Hong;Lim, Ohk-Kun;Kim, Chun-Gi;Lapchuk, Anatoliy;Ihar, Shyshkin;Lee, Seung-Wan;Kim, Sun-Ki;Hwang, Young-Nam;Woo, Ki-Suk;Shin, Seung-Wan;Kang, Jung-Chul;Park, Dong-Hyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.551-555
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    • 2006
  • A new type of diffractive spatial optical modulators, named SOM, has been developed by Samsung Electro-Mechanics for projection display and other applications. A laser display in full HD format $(1920{\times}1080)$ was successfully demonstrated by using prototype projection engines having SOM devices, signal processing circuits, and projection optics.

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Organic Rice (Oryza sativa L.) Production in Eco-friendly Complex using Gelatin·Chitin Microorganisms (친환경 광역단지 내 젤라틴·키틴분해미생물을 이용한 유기 벼 생산)

  • Choi, Seung-Hee;Cha, Kwang-Hong;Seo, Dong-Jun;Park, Hung-Gyu;Kwon, Oh-Do;An, Kyu-Nam;Lee, Jai-Hak;Kim, Kil-Yong;Jung, Woo-Jin
    • Korean Journal of Organic Agriculture
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    • v.26 no.4
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    • pp.629-647
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    • 2018
  • This study was carried out to investigate the economic value of organic rice production using gelatin chitin microorganisms in eco-friendly complex, Gongsan, Naju city. The soil condition of experiment paddy field was Jeonbuk series and silt loam with a slightly poor drainage. Except for the high effective silicate, the chemical characteristics of soils used were included in the optimum range of paddy soils in Korea. In growth, plant length, tiller number, ear number, and ear length were observed to be higher in conventional paddy fields than organic paddy fields. However, number of grain per panicle and grain filling ratio (%) were higher in organic paddy fields than conventional paddy fields. Incidences of diseases and insect pests were slightly higher in the organic paddy fields. Water weevil, sheath blight, rice leaf roller and rice blast were more occurred in organic paddy field. On the other hand, false smut was higher occurred in conventional paddy field. There was a significant negative correlation between rice sheath blight and rice leaf roller, and rice yield. In the milled rice quality, the quality of organically cultivated milled rices was lower by the increase of broken rice than that of conventionally cultivated milled rices. The quality and palatability of rice were higher in organic cultivation with decreasing of protein content. Net income of conventionally and organically cultivated rice was 360,000 won/10a and 610,000 won/10a, respectively. Premium net income of the organically cultivated rice was 68%.

Superficial Esophageal Cancer Treated with Multidisciplinary Care: A Case Report (다학제 접근을 통해 치료에 성공한 표재성 식도암 1례)

  • Oh, Gyu Man;Park, Moo In;Jung, Kyoung Won;Kang, Sung Min;Son, Min Young;Kim, Jae Hyun;Moon, Won;Park, Seun Ja
    • Journal of Digestive Cancer Reports
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    • v.8 no.1
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    • pp.71-75
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    • 2020
  • Esophageal cancer is easy to infiltrate and metastasize because esophagus does not have serosa, and is difficult to remove it because esophagus is in the middle of the chest. Because of this, treatments of esophageal cancer do not always follow the guideline. In this situation, efforts to increase treatment efficiency and improve survival rate through multidisciplinary treatment are increasing. In this case, we report the patient with three superficial esophageal cancers (one in cervical esophagus and two in thoracic esophagus). The patient was treated with concurrent chemoradiotherapy instead of surgery through multidisciplinary discussion. The patient reached a complete remission through this discussion. This case is intended to inform the usefulness of multidisciplinary treatment in patients with esophageal cancer.