• Title/Summary/Keyword: 최정환

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A Newly Recognized Desmometopa Loew, 1866 (Diptera: Milichiidae), A Commensalistic Dipteran Genus, in South Korea (한국의 미기록속 이마줄불청객파리속(신칭)(파리목: 불청객파리과)에 대한 보고)

  • Seung-Su Euo;Jeong-Hwan Choi;Il-Kwon Kim;A Young Kim
    • Korean journal of applied entomology
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    • v.62 no.4
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    • pp.325-331
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    • 2023
  • Desmometopa Loew, 1866 is newly recognized in the Korean Peninsula, based on Desmometopa microps Lamb, 1914 that is new to Korean insect fauna. The species is known to have commensalistic habits with predacious insects and spiders. Diagnosis, description, images and DNA barcode sequences are provided, based on the obtained adult specimens.

Postoperative Change in Hypertrophic Rhinitis(Study Using Nasometer, CSL and Acoustic Rhinometer) (비후성 비염환자에서 음성검사 및 음향비강통기도검사를 이용한 수술전후 비교)

  • 유영삼;우훈영;윤자복;최정환;조경래
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.12 no.1
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    • pp.34-38
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    • 2001
  • Background and Objectives : With the development of computerized systems, an objective evaluation methods of nasal speech and nasal geometry have become readily available by means of a simple, noninvasive technique. In this study, we assessed the nasality, nasal formant, nasal volume and nasal area in patients with hypertrophic rhinitis before and after turbinate surgery. Material and Method : With the nasometer, we measured nasalance, which reflects the ratio of acoustic energy output of nasal sounds from the nasal and oral cavities. With CSL 4300B, we measured nasal formants. We used acoustic rhinometer to measure nasal area and nasal volume. Postoperative changes of above factors were compared with preoperative values. Paired t-test and Pearson's correlation were used for statistical analysis. Results : The first nasal formant frequency, nasalance scores of three passages(baby, mamma and rabbit passages), minimal cross sectional area(MCA) of narrow side, nasal volume of narrow side and nasal volume of wide side had increased significantly after turbinate surgery (p <0.05). The MCA and nasal volume of narrow side and MCA of wide side showed significant correlation with nasalance score of rabbit passage and baby passage showed significant correlation with nasal volume of narrow side(p<0.05). Conclusion : There were significant increases in nasalance scores, first nasal formant frequency, MCA and nasal volume after turbinate surgery. Thus, we must consider the possibility of voice changes postoperatively in professional voice users.

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An Adaptive Recommendation Service Scheme Using Context-Aware Information in Ubiquitous Environment (유비쿼터스 환경에서 상황 인지 정보를 이용한 적응형 추천 서비스 기법)

  • Choi, Jung-Hwan;Ryu, Sang-Hyun;Jang, Hyun-Su;Eom, Young-Ik
    • Journal of KIISE:Software and Applications
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    • v.37 no.3
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    • pp.185-193
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    • 2010
  • With the emergence of ubiquitous computing era, various models for providing personalized service have been proposed, and, especially, several recommendation service schemes have been proposed to give tailored services to users proactively. However, the previous recommendation service schemes utilize a wide range of data without and filtering and consider the limited context-aware information to predict user preferences so that they are not adequate to provide personalized service to users. In this paper, we propose an adaptive recommendation service scheme which proactively provides suitable services based on the current context. We use accumulated interaction contexts (IC) between users and devices for predicting the user's preferences and recommend adaptive service based on the current context by utilizing clustering and collaborative filtering. The clustering algorithm improves efficiency of the recommendation service by focusing and analyzing the data that is collected from the locations nearby the users. Collaborative filtering guarantees an accurate recommendation, even when the data is insufficient. Finally, we evaluate the performance and the reliability of the proposed scheme by simulations.

Craniosynostosis Occurring between Siblings (남매간에 발생한 두개골조기유합증)

  • Choi, Jeong-Hwan;Kim, Myung-Hoon;Kim, Min-Su;Jung, Gyu-Yong;Lee, Keun-Cheol;Kim, Seok-Kwun
    • Archives of Craniofacial Surgery
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    • v.14 no.2
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    • pp.115-118
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    • 2013
  • Craniosynostosis is a congenital anomaly in which cranial sutures close prematurely and restrict skull growth. In this paper, the case of two siblings, a male and a female, who were both diagnosed as craniosynostosis is reported. They underwent corrective osteotomy for cranial vault remodeling. A 22-month-old female infant who was brought to the department of plastic and reconstructive surgery of the authors' hospital was diagnosed with plagiocephaly. At the same time, her 7-month-old brother was diagnosed with brachycephaly. In the case of the female infant, corrective coronal osteotomy and supraorbital bar advancement were performed. Her brother underwent frontal advancement osteotomy using Tessier's tongue in the groove procedure. After the correction of the craniosynostosis, the two patients recovered in several days later, and the results were good in both cases cosmetically and functionally. They showed normal head circumference increasing curves and no symptom of functional disorder in their last follow-up. Isolated or nonsyndromic craniosynostosis is sporadic but mostly autosomal dominant. This paper presents a case of craniosynostosis with a genetic tendency; and although it occurred between siblings, the affected lesions differed. Thus, appropriate diagnosis and management in patients are needed.

Dial Menu User Interface Using Touch Screen (터치스크린을 이용한 다이얼 메뉴 유저 인터페이스)

  • Choi, Jung-Hwan;Kim, Youn-Woo;Jang, Hyun-Su;Eom, Young-Ik
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.584-589
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    • 2008
  • The in put system using the touch screen directly makes the input signals by the contact on the screen without the assistance of peripherals such as a pen or hands. These kinds of input systems using the flexible hands is maximizing suppleness and intuition of the input rather than those systems using a keyboard or a mouse which are moving a cursor or typing a word. However, using hands for an input may give rise to a mistake in control. And there are few interfaces utilizing the touch screen. Incorrectness and insufficiency of the interface are the weak point of the touch screen systems. In this paper, we propose the dial menu user interface for the mobile devices using touch screen for an efficient input. In this method, it consists of 2 states(Inactive states, Active states) and 4 actions(Rotation, Zoom in, and Zoom out, and Click). The intuitive control utilizing the suggested method overcomes the incorrect pointing, weak point of the touch screen system, and boosts the searching menu by utilizing the drag function of the touch screen.

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Review on the detailed standards for Quantitative Risk Analysis in High Speed Railway Tunnels (고속철도 터널의 정량적 위험도 분석(QRA)을 위한 세부기준에 관한 고찰)

  • Choi, Won-Il;Choi, Jeong-Hwan;Moon, Yeon-Oh;Kim, Seon-Hong;Yoo, Ho-Sik
    • Tunnel and Underground Space
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    • v.18 no.6
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    • pp.393-407
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    • 2008
  • To protection of fire accident and to minimize danger of spreading the disaster. in railway tunnel, MCT (the Ministry of Construction and Transportation) published "Rules about the Safety Standard of Railroad (2005.10.27)" and "The Detailed Safety Standard of Railroad (2006.9.22)". QRA(Quantitative Risk Analysis) results are applied to establish the fire protection facilities in railway tunnel so that institute the reasonable application about the fire safety facilities However, it is difficult to perform the fire safety design due to lack of the detailed standards about event scenario, fire intensity, incidence rate of accidents etc. Therefore, This paper introduces the practical method about detailed standards of QRA.

The Experience of Using Current Perception Threshold in Bilateral Thoracic Outlet Syndrome (TOS) Patient -A case report- (흉곽출구증후군 환자에서 Current Perception Threshold (CPT) 사용 경험)

  • Choi, Jeong-Hwan;Choi, Jin-Hwan;Sung, Choon-Ho;Park, Jong-Wook
    • The Korean Journal of Pain
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    • v.13 no.1
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    • pp.97-100
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    • 2000
  • Thoracic outlet syndrome (TOS) is a combination of signs and symptoms caused by the compression of the vital neurovascular structure at the thoracic outlet region. It may stem from a number of abnormalities, including degenerative or bony disorders, trauma to cervical spine, fibromuscular bands, vascular abnormalities and spasm of the anterior scalene muscle. CPT (current perception threshold) is defined as the minimum amount of current applied transcutaneously that an individual consciously perceives. It enables quantification of the hyperesthesia that precedes progressive nerve impairment, as well as hypoesthetic conditions. We experienced a case of thoracic outlet syndrome caused by fibrosis of anterior scalene muscle. The patient was a 30 years old woman with a 3 years history of numbness on the ulnar side, progressive weakness and coldness of both hand, tiredness in the left arm, nocturnal pain in the left forearm, and pain in the left elbow, shoulder and neck. Conservative treatment, stellate ganglion block, cervical epidural block, anterior scalene block and previous operation, including both carpal tunnel release, provided no remarkable relief to the patient. A left scalenectomy and first rib resection were performed by transaxillary approach and left cervical root neurolysis was done. After surgery, we measured CPT using neurometer and found conditions worsening in the opposite arm. We performed the same procedure on right side, and followed by CPT measurement. This case suggests that CPT is a useful measurement of recovery and progression of TOS.

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A Double-blind Comparison of 0.125% Ropivacaine with Fentanyl and 0.125% Bupivacine with Fentanyl for Labor Analgesia Using Patient-Controlled Epidural Infusion (지속적 통증조절기를 이용한 경막외강으로 Fentanyl을 첨가한 0.125% Ropivacaine과 0.125% Bupivacaine 주입시 분만통 조절에 대한 효과)

  • Choi, Jeong-Hwan;Lee, Hae-Jin;Sung, Choon-Ho
    • The Korean Journal of Pain
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    • v.13 no.1
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    • pp.67-73
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    • 2000
  • Background: This study intends to evaluate the benefits of the administation of continuous infusion and demand doses of 0.125% ropivacaine compared with 0.125% bupivacaine after addition of fentanyl using patient controlled epidural analgesia (PCEA) for pain control during labor. Methods: Thirty-nine American Society of Anesthesiologists physical status 1 or 2 parturients were randomized by double blind design to receive either 0.125% bupivacaine with fentanyl 1 ug/ml or equivalent concentration of ropivacaine/fentanyl using PCEA; with 6~8 ml/hr basal rate, 3 ml bolus, 5 min lockout, 30 ml/hr dose limit. We assessed analgesia, the amount of study solution used in PCEA, sensory levels, motor block (0~3 scales), side effects and patient satisfaction. A postpartum questionnaire was carried out afterward. Results: There were no differences in visual analogue scores (VAS) for pain, hourly study solution use, sensory levels, side effects and patient satisfaction between groups. However, patients administered ropivacaine/fentanyl had significantly less demand, less administered in PCEA, less numbness and restriction of movement compared with patients in the bupivacaine/fentanyl group. Conclusions: Ropivacaine 0.125% with fentanyl, when administerd epidurally by PCEA for labor analgesia, was equally efficious as bupivaciane 0.125% with fentanyl, having with minimal numbness and restriction of motion.

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Hull Strength Evaluation of Dissemination 12ft Bass Fishing Boat Using FEA (보급형 12피트 배스 낚시보트의 유한요소해석을 통한 선체강도평가)

  • Oh, Young-Cheol;Ko, Jae-Yong;Chung, Se-Yun;Choi, Jeong-Hwan;Kim, Hyeon-Jin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2012.06a
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    • pp.225-226
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    • 2012
  • Recently, In the domestic is used mainly fiberglass reinforced plastic(GRP) and is built for maritime leisure vessel & structures. but it less attention is insufficient for ship of structural strength assessment of maritime leisure vessel. Therefore, The structural strength evaluation suitable for the domestic situation formulate and is applied to domestic regulations of "Guidance for Recreational Crafts" of Korea register of shipping(KR) & "Reinforced plastic line structure standards" of Ministry of Land, Transport and Maritime Affairs. the structural design and finite element analysis(FEA) to ensure the reliability.

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Radial Performances of Spiral-Grooved Spherical Air Bearings (나선홈을 갖는 반구형 공기 베어링의 반경 방향 성능 측정)

  • Park, Keun-Hyung;Choi, Jeong-Hwan;Choi, Woo-Chon;Kim, Kwon-Hee;Woo, Ki-Myung;Kim, Seung-Kon
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.2 s.95
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    • pp.23-30
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    • 1999
  • This paper investigates the radial performance of self-acting spiral-grooved air bearing, used to support small high-speed rotating bodies. Repeatable runout, nonrepeatable runout, stiffness and supporting load are selected as the performance. The clearance between rotor and stator, the stator groove depth, and the rotating speed are chosen as three main parameters affecting the performances. Force application and displacement measurement are done in a noncontact manner, in order not to disturb operation: electromagnetic force is applied to the rotor and gap sensors are used to measure the displacement of the rotor. Experimental results show that repeatable runout decreases as speed, groove depth and clearance decrease. Nonrepeatable runout decreases as clearance decreases, and it has a minimum value at $5.5{\mu}m$ of grove depth and a maximum value at speed of 18.000rpm. Stiffness increases as speed increases and clearance decreases, and has a maximum value around $5.5{\mu}m$ of groove depth. The relationship between force and displacement is linear for small displacement, but becomes nonlinear for large displacement. Supporting load is linearly proportional to the stiffness, and it is a maximum value around $4.75{\mu}m$ of clearance.

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