• Title/Summary/Keyword: Jeon Chang-geun

Search Result 104, Processing Time 0.027 seconds

Studies on the Optimization of Contact Oxide Etching Process Using Taguchi Method (Taguchi 방법을 사용한 콘택 산호막 식각 공정 최적화 연구)

  • Jeon, Yeong-Jin;Kim, Chang-Il;Gu, Jin-Geun;Yu, Hyeong-Jun
    • Korean Journal of Materials Research
    • /
    • v.5 no.1
    • /
    • pp.63-74
    • /
    • 1995
  • Process optimization experiments based on the Taguchi method were performed in order to set up the optimal process conditions for the contact oxide etching process module which was built in order to be attached to the cluster system of multi-processing purpose. From the two times experiments of Taguchi method, the overall behaviors of the etchmg characteristics depending upon the equipment parameters were understood at the 1st Taguchi experiment, the detail and optimal process conditions were extracted from the 2nd Taguchi experiment. As a final analysis of experimental results, the optimal etching characteristics were obtalned at the process conditions of $CHF_{3}/CF_{4}$ gas flow rate=72/8 sccm, chamber pressure=50 mTorr, RF power=300 Watts, magnetic field intensity=90 Gauss.

  • PDF

Study on the Development of Sensors for Distance Measure Using Ultrasonic (초음파 이용 거리측정을 위한 센서 개발에 관한 연구)

  • Park, Geun Chul;Lee, Seung Hee;Park, Chang Soo;Kim, Dong Won;Kim, Won Taek;Jeon, Gye Rok
    • Journal of Sensor Science and Technology
    • /
    • v.23 no.1
    • /
    • pp.46-50
    • /
    • 2014
  • In this paper, we report a novel algorithm based on phase displacement, which supplements conventional TOF methods for distance measurement using an ultrasonic wave. The proposed algorithm roughly measures the distance between the transmission part and the receiving part by using the initial TOF. Thereafter, the precise distance is determined by measuring the phase displacement value between the synchronizing transmission signal and the signal obtained at the receiving end. A distance measurement experiment using a micrometer was performed to verify the accuracy of the ultrasonic wave sensor system. We found that the mean errors from the one adopting the distance measurement algorithm based on phase displacement varied from a minimum of 0.03 mm to a maximum of 0.09 mm. In addition, the standard deviation varied from a minimum of 0.04 mm to a maximum of 0.07 mm, thus giving a precision of ${\pm}0.1$ mm.

Simple Obesity Treatment by Single Intervention of Herbal Medicines without Ephedra Herba: A Case Report (마황을 포함하지 않은 한약처방 단일중재에 의한 단순비만 치료 : 증례보고)

  • Jeung, Chang-woon;Jeon, Sun-woo;Jeong, Sin-yeong;Jo, Hee-geun
    • The Journal of Internal Korean Medicine
    • /
    • v.40 no.6
    • /
    • pp.1294-1302
    • /
    • 2019
  • Objective: Glucagon-like peptide 1 (GLP-1), one of the gut peptide hormones, has an action to induce satiety, and its effect as an anti-obesity agent is known. Recently, it has been reported that many herbal medicines have an anti-diabetic effect through inhibition of DPP-4 enzyme and inducing of GLP-1 secretion. It is therefore suggested that GLP-1 may be effective for the treatment of obesity. In this study, we report a case of male obese patients treated with herbal medicine as a GLP-1 secretagogue. Methods: In this study, the patient took a fixed prescription of herbal medicine for 10 weeks and recorded his weight at each visit. Results: This prescription produced significant weight loss (BMI loss>5%). In the follow-up period after two weeks, the trend of weight loss was observed continuously. Conclusion: This prescription can be an alternative to ephedra herba-based obesity treatment.

Design and Ground Test of Propeller for 50 m-long Airship Propulsion (50 M급 비행선 추진용 프로펠러 설계 및 지상성능시험)

  • Kim,Hyeong-Jin;Lee,Chang-Ho;Jeon,Seong-Min;Im,Byeong-Jun;Lee,Jin-Geun;Yang,Su-Seok
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.31 no.10
    • /
    • pp.112-119
    • /
    • 2003
  • Design analysis and grow1d test on propellers for 50 m-long airship propulsion were conducted. The design analysis code developed by adopting the vortex-blade-element theory was applied to the design of optimum propeller at the condition of maximum flight speed at sea level. In order to validate the performance of the propeller, ground test of the propeller was performed, and thrust and torque were measured for several different pitch angles at static condition. The power coefficients and thrust coefficients obtained by the test compared well with the analysis results.

Nano-indenter를 통한 유기발광소자(OLED)용 Ag전극의 표면처리에 따른 물성변화 연구

  • Kim, Ju-Yeong;Kim, Su-In;Lee, Gyu-Yeong;Kim, Hyeong-Geun;Jeon, Jae-Hyeok;Jeong, Yun-Jong;Kim, Mu-Chan;Lee, Jong-Rim;Lee, Chang-U
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2011.08a
    • /
    • pp.224-224
    • /
    • 2011
  • OLED (Organic Light-Emitting Diode) 디스플레이에서는 반사율이 가장 높은 silver (Ag)가 쓰이고 있지만, 소자에서 요구되는 일함수의 불일치 때문에 전극과 유기물간에 에너지 장벽이 발생하여 발광효율을 낮추는 요인이 되고 있다. 본 논문에서는 Ag 전극의 work function을 조절하기 위한 연구를 진행하였다. Ag를 rf magnetron sputter를 이용해 glass위에 증착한 후 furnace에서 300$^{\circ}C$, 30분간 공기중에서 열처리 하였고. 또 다른 샘플은 산소분위기에서 표면에 상압플라즈마로 처리 시간(30, 60, 90, 120 sec)을 각기 다르게 하여 샘플을 제조하였다. Ag전극은 Nanoindentation을 통해 국부 영역에 대한 물리적 특성의 변화를 측정하였고 Kelvin Probe Force Microscopy (KPFM)을 이용해 샘플의 포텐셜을 측정했다. 그 결과 열처리한 샘플은 포텐셜값은 가장 커졌지만 균일도가 낮아졌다. 30 sec, 120 sec 플라즈마 처리한 샘플은 탄성계수, 경도값, 및 Weibull modulus를 극히 낮게 만들었지만 60s, 90s 플라즈마 처리는 샘플의 경도값 균일도를 증가시켰다.

  • PDF

Literature Review on Herbal Medicine Treatment of Psoriasis Based on Chronic Low-grade Inflammation Theory (만성 저등급 염증이론을 바탕으로 한 건선의 한약치료에 대한 문헌고찰)

  • Jeung, Chang-Woon;Jeon, Sun-Woo;Jo, Hee-Geun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.31 no.4
    • /
    • pp.22-30
    • /
    • 2018
  • Objectives : The aim of this study is to investigate the relationship between chronic low grade inflammation theory, psoriasis, and herbal medicine. Methods : We reviewed recent studies on the relationship between chronic low-grade inflammation, psoriasis, and herbal medicine through Pubmed. Results : The pathological basis for psoriasis is the action of inflammatory mediators by the activation of the immune response, which can be a cause of various cardiovascular, metabolic and psychological symptoms of psoriasis patients, in addition to skin lesions. The herbal medicines improve these inflammatory conditions and improve local lesions through herbal medicine such as Qingdai, which have a strong inhibitory effect on IL-17,22 production. Conclusions : Herbal medicines used in psoriasis are thought to be effective not only for the improvement of local psoriasis lesions through anti-inflammatory effect but also for the improvement of systemic inflammation associated with chronic low grade inflammation.

Investigation of the electric currents on the skin of twelve meridian collaterals' meridian points below the elbow-knee joints ( I ) (십이경맥중(十二經脈中) 주슬관절이하(?膝關節以下) 경혈(經穴)의 생체전류량(生體電流量) 측정(測定) ( I ))

  • Jeon, Byeong-Hun;Kim, Jae-Hyo;Son, In-Cheol;Jeong, Dong-Myeong;Hwang, Geun-Chang;Jeong, U-Yeol
    • The Journal of Korean Medicine
    • /
    • v.17 no.1 s.31
    • /
    • pp.84-110
    • /
    • 1996
  • Meridian collateral and meridian points have been the base of acupuncture and moxibustion therapy. Also the theory have composed the main portion of Oriental Medicine. But the mechanism and scientific background has not been completely eatablished, and the research on the objectification of diagnosis of meridian collateral and meridian points, and acupuncture & moxibustion therapy has been necessary nowadays. A new understanding of value of Oriental Medicine has been increasing, the scientific understanding of meridian collateral and meridian points should have been examined. The system of meridian collateral and meridian points was very interesting topics between the scientists in the world. Especially, the elucidation of function and mechanism of Qi(氣) was very important in the scientific theme of 21th century. But there has been many difficulties in the study of meridian collateral and meridian points, since the system of meridian collateral and meridian points has the complexed function and vague structure in the organism. As the one of index of meridian points, the electric current has been used. In this report, the volume of electric current on the skin around the meridian points was investigated. The results of investigation showed the meridian points have higher electric current volume than non-meridian points.

  • PDF

Adverse Drug Reaction of Chinese Herbal Injection: Focusing on the Anaphylaxis Reaction (중약주사제의 약물유해반응: 아나필락시스 반응을 중심으로)

  • Jeung, Chang-woon;Jeon, Sun-woo;Jo, Hee-Geun
    • Journal of Korean Medicine Rehabilitation
    • /
    • v.30 no.4
    • /
    • pp.133-142
    • /
    • 2020
  • Objectives Studies on Chinese herbal injections are increasing. But, its safety are still not well reported. We have reviewed the literature related to the safety of Chinese herbal injection, especially those related to anaphylaxis. Methods The PubMed database was used to select the literatures related to anaphylaxis in China and to study the quality control and safety of Chinese herbal injection. Results Chinese herbal injection is a major traditional medical treatment in China, but it is the cause of adverse drug reactions including anaphylaxis. In order to solve this problem, various proposals have been made to identify the pharmacological and chemical causes of major side effects and to use them safely clinically. In addition, various researches have been conducted from preclinical to postmarketing surveillance to secure the safety of Chinese herbal injection. Based on this, it was found that various efforts are needed to secure the safety of bee sting needles. Conclusion In order to secure the safety of chinese herbal injections, it is necessary to identify the main mechanism of action and the pharmacological components contributing to it, and to develop a standardized formulation based on this. In addition, institutional pharmacovigilance is required.

DRDoS Attacking Scenario and Countermeasure for Using Weakness of SSDP Protocol in IoT Device (IoT기기에서 SSDP프로토콜 취약점을 이용한 DRDoS공격시나리오 및 대응방안)

  • Hong, Geun-Mok;Won, Jun Hee;Lee, Keun-Ho;Jeon, You-Boo;Lee, Chang-Jun
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2016.04a
    • /
    • pp.280-282
    • /
    • 2016
  • 오늘날 IoT 사물기기들의 사용 범위가 늘어나면서 해커들은 IoT 기기에서 네트워크상의 서비스 및 정보검색의 기능을 하는 프로토콜인 SSDP의 취약점을 악용하여 SSDP DRDoS(분산 반사 서비스 거부) 공격이라는 새로운 형태의 공격을 만들어 공격을 시도하고 있다. 이는 단순히 우리 생활에서 쓰이는 IoT 기기의 위협뿐만 아니라 사람의 생명이나 주요 기반시설 등에서 사용되어지는 IoT기기들의 공격으로 이어지면 큰 위험을 나타낼 수 있다. 앞으로 IoT기기들이 점차 증가되어 생활에 편리함과 실용성을 가지고 오는 반면에 해커들은 더욱더 교묘하고 복잡하게 공격을 시도를 할 것이다. 특히 본 논문에서는 DRDoS의 몇 가지 공격방법을 알아보고 그중에 IoT 기기에서 사용되어지는 SSDP프로토콜의 관련연구 및 공격방법들을 알아보고 공격시나리오 및 대응방안을 제안한다.

Blue OLEDs Utilizing Spiro[fluorene 7,9'-benzofluorene]-type Compounds as Hosts and Dopants

  • Kim, Joo-Han;Jeon, Young-Min;Jang, Ji-Geun;Ryu, Sang-Ouk;Chang, Ho-Jung;Lee, Chil-Won;Kim, Joon-Woo;Gong, Myoung-Seon
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.3
    • /
    • pp.647-652
    • /
    • 2009
  • A novel spiro-type host material, 5-[4-(1-naphthyl)phenyl]-spiro[fluorene-7,9'-benzofluorene] (BH-1PN) and three new dopants, namely, 5-[diphenylamino)phenyl]-spiro[fluorene-7,9'-benzofluorene] (BH-1TPA), 5-[4-(N-phenyl (m-tolyl)amino]-spiro[fluorene-7,9'-benzofluorene] (BH-1MDPA) and 5-[(N-phenyl)-2-naphthyl]amino-spiro[fluorene- 7,9'-benzofluorene] (BH-1NPA) were designed and successfully prepared using the Suzuki or amination reactions. The electroluminescence characteristics of BH-1PN as a blue host material doped with each of the blue dopants were evaluated. The structure of the device is ITO/DNTPD/NPB/BH-1PN:5% dopant/Alq3/Al-LiF. The device obtained from BH-1PN doped with diphenyl-[4-(2-[1,1;4,1]terphenyl-4-yl-vinyl)phenyl]-amine (BD-1) showed good color purity, efficiency, luminance, and current-density characteristics.