Influence of an External Electrode on a Plasma Plume Ejected from a Syringe Electrode inside a Glass Tube

정종윤,김윤중,Min Kyung Lee,한국희,김현철,Dongjun Jin,김정현,최은하,Han Sup Uhm,조광섭 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.4

An atmospheric plasma jet device consisting of a syringe electrode inserted into a glass tube has been introduced. A high voltage is applied to the syringe electrode with a DC-AC inverter at a few tens of kHz. The external electrode on the outside surface of the glass tube is grounded. The current-voltage characteristics and the plume length are investigated with respect to the electrode gap distance d and the external electrode width w. The breakdown voltage depends on the gap distance d while the width w acts as a capacitance in the AC-discharge circuit. When the gap distance is short and the width is narrow, the breakdown voltage is lower and is accompanied by a low current by which the plume length is adjustable from 0 mm initially to a saturated value of about 10 mm as the voltage is increased after breakdown. If the device has a long gap and a wide width, a high breakdown voltage and a high current initially make a plume of finite length at the breakdown, which saturates shortly thereafter. This allows the plasma emission current and the plume length to be controlled with a short gap distance d and a narrow width w of the external electrode.

Verification of Design and Safety of a Nozzle Plate for Steam Turbines

정종윤,박희성,김준섭 한국산업경영시스템학회 2018 한국산업경영시스템학회 학술대회 Vol.2018 No.춘계

대형선박의 발전에 사용되는 증기터빈에는 핵심부품으로서 노즐플레이트가 활용되는데 정밀 산업 이 발전한 요즘에도 오래 전의 설계와 생산방식을 답습하고 있다. 노즐플레이트는 많은 터빈 블레이드와 이너링, 아우터링으로 구성되어 있고 이들을 서로 용접하여 제작한다. 용접 시에 블레이드의 뒤틀림 등으로 인하여 그 용접위치에 약간의 변위가 발생하여 각 블레이드 간의 pitch가 불균일하여지고 이로 인해 플레이트의 성능 저하가 우려된다. 이러한 점을 개선하기 위해 용접식 보다는 pitch의 등간격을 유지시키는데 유리한 조립식 설계로 전환하는 것이 필요하다. 이는 설계 변경을 해야 하며 또한 새로운 설계 시에 그에 대한 응력을 기초로 하는 구조해석과 장시간 사용되었을 경우에 대비하여 내구성 시험이 수반되어야 한다. 본 연구는 터빈 블레이드의 구조 설계를 조립식으로 변경하고 이의 결합성을 검토한 후 사이버 공간상에서 안전성 검증을 통하여 실용 가능성을 입증하고자 한다.

Analysis of Effect of Eggshell Membrane Patching for Moderate-to-Large Traumatic Tympanic Membrane Perforation

정종윤,윤희철,김태민,주재우,송인식,나윤찬,장지원,임기정,최준 대한청각학회 2017 Journal of Audiology & Otology Vol.21 No.1

Background and Objectives: To evaluate the effect of eggshell membrane (ESM) patching for tympanic membrane (TM) perforation, and to investigate correlations between healing time and age, gender, patching time, perforation size, and perforation location. Subjects and Methods: One hundred and seventy-five patients diagnosed with traumatic TM perforation at the Department of Otorhinolaryngology-Head and Neck Surgery, Korea University Ansan Hospital, between January 2008 and October 2013. Patients were divided into two groups, according to perforation edge approximation or ESM patching treatment. Healing time was compared between the group that received perforation edge approximation and the group that received ESM patching. Perforation grade, age, onset, and location were also compared between the two groups. Results: ESM patching significantly improved healing time compared to spontaneous healing, especially in patients with moderate or large traumatic TM perforations (≥grade II). However, patient age, gender, perforation location, and especially timing of procedure, did not significantly affect healing time. Conclusions: ESM patching can be a good treatment choice to promote tympanic membrane healing in large traumatic TM perforations.

Bezier Patch의 자유곡면 보간

정종윤 國立 昌原大學校 産業技術硏究所 2000 産技硏論文集 Vol.14 No.-

산업사회가 발달해지고 인간의 욕구가 다양해질수록 소비자는 기능이 다양하고 외형이 심미적인 제품을 요구하게 된다. 현대의 소비자들에게 제품의 외형이 구매를 결정하는 중요한 요인으로 작용하기 시작했다. 이러한 관점으로 볼 때 부드럽고 안정감을 주는 곡면의 형성은 매우 중요한 역할이라고 할 수 있다. 본 연구에서는 제품의 외형을 보다 부드럽게 형성하기 위해 Bezier patch를 이용하여 곡면을 보간하는 방법을 제시하였다. 곡면을 형성하기 위한 자료는 모형의 표면을 측정하여 얻는다. 이러한 이산형 data로부터 Bezier patch의 곡면식을 구하고 여러개의 patch를 서로 부드럽게 연결시켜 하나의 부드러운 곡면을 형성하여 연속형 곡면 data를 구한다.

내시경 소모품 간소화로 인한 비용절감

정종윤 한국의료QA학회 2008 가을학술대회 Vol.2008 No.3

Turbocharger 용 Blade 개발을 위한 공정설계

정종윤,서광선,강재관 한국산업경영시스템학회 2016 한국산업경영시스템학회 학술대회 Vol.2016 No.추계

競技種目別로 본 優秀選手의 體格.體力의 比較 및 基準設定에 관한 硏究

朴哲浩,金榮俊,鄭琮潤 東亞大學校 附設 스포오츠科學硏究所 1985 스포츠科學硏究論文集 Vol.3 No.-

This research has the aims of making known what the characteristics of physique and physical fitness factors are and establishing a desirable model of standard evaluation for talented collegiate athletes according to their games. Method All 157 talented athletes of 11 items of sports who attend colleges in Pusan and chosen for the research, and standard evaluation by means of T-score was made on the basis of the measurement results of 18 physique and 28 physical fitness factors. The numbers of student athletes in each event are 29 in baseball, 27 in socer, 22 in wrestling, 16 in taegwondo, 15 in judo, 14 in ssirum, 12 in bosing, 7 in track & field, 5 in archery, and 3 in cycling. Conclusion 1. The first three groups which attained higher records in standing height, body weight of chest and sitting height were those of ssirum, field & track and judo, while those of Taegwondo and archery were the lowest 2. In such factors as length of upper arm and length of limb, the groups of field & track, ssirum and baseball were highest in order, while those of archery and cycling were the lowest in their scores. 3. In girths of upper arm, forearm and thigh, the athlete groups of ssirum, judo and field & track in order got higher scores than others, while the lowest two groups were those of Taegwondo and archer. 4. In strengths of grip, upper arm in extensor and flexor and leg in extensor and flexor, the groups of ssirum, field & track and judo were the highest three, and those of archery and boxing were the lowest two. 5. In the relative strength factor, the groups of field & track, archery and cycling in the score order were the highest, and judo and boxing groups were the lowest. 6. In the static muscular endurance factor, the player groups of wrestling, soccer and archery were in order the highest three, and those of baseball and boxing were the lowest two. 7. In the power factor, the collegiate athlete groups of field & track, fencing, ssirum and baseball were the highest four in the score order, and those of boxing and archery were the lowest two. 8. In the factor of flexibility, the athletic groups of fencing, archery and Taegwondo were the highest three, while those of field & track and boxing showed the lowest marks. 9. In the factor of cardiovascular funciton and endurance, the student player groups of field & track, ssirum and soccer were the highest three, while those of boxing and archery received the lowest scores. 10. A model of standard evaluation of physique and physical fitness for the subjects, namely talented athletes, by means of T-score were presented in Table 5-1, 2, 3 and 4.

시뮬레이션을 이용한 노즐플레이트의 구조안전성

정종윤,박희성,김준섭 한국산업경영시스템학회 2018 한국산업경영시스템학회지 Vol.41 No.3

Modern manufacturing industries is to produce both precise and robust mechanical parts without failure while they are in service. In order to prevent a part failure for its lifetime, a mechanical design for a part should be examined on a basis of mechanical simulation. A nozzle plate, being a key part in steam engines, changes flow directions of steam in a turbine used in power plant. This paper is to the design and test for part safety and durability. Currently, nozzle plates are fabricated by welding nozzles to their plates. Welding causes some defects on the used materials while they are being manufactured. Another major defect is un-even pitches between welded nozzles. Welding causes phase changes because of high melting temperature of metal. This leads to decay on the welding spots, which weakens their structural strength and then, may lead to early damages on mechanical structures. This research proposes assembly-typed nozzle plate without welding. From the beginning, nozzle and plate are designed for insertion-typed assembly. Nozzle head and foot are designed in accordance with the grooves on outer ring and inner ring of a plate to make mating surfaces. Then the nozzle plate should be proved for structural and fatigue safety before they are put in manufacturing. This research adopts commercial softwares for modeling and mechanical simulation. The test result shows that the design with smaller mating area and deeper insertion produces higher safety in terms of structure and durability. From the conclusion, this paper proposes the assembly-typed nozzle plate to replace the welding typed.

FEM 시뮬레이션을 이용한 유니버설 조인트의 구조안전성

정종윤 한국산업경영시스템학회 2018 한국산업경영시스템학회지 Vol.41 No.4

Mechanical components are to be produced with accurate dimensions in order to function properly in assemblies of a machine. Once designs of mechanical components are created, designers examine the designs by adopting many known experimental methods. A primary test method includes stress and strain evaluation of structural parts. In addition, fatigue test and vibration analysis are an important test method for mechanical components. Real experiments at a laboratory are established when products are manufactured. Since design changes should be done before producing the designs in factories, rapid modifications for new designs are required in production industries. FEM simulation is a proper choice for a design evaluation with speed at a detail stage in design process. This research focuses modeling and mechanical simulation of a mechanical component in order to ensure structural safety. In this paper, a universal joint, being used in driving axels of vehicles, is studied as a target component. A design model is created and tested in some ways by using commercial software of FEM. The designed component is being twisted to transmit heavy power and thus, torsional stress should be under strengths of the component’s material. The next is fatigue analysis to convince fatigue cycles to be within the endurance limit of the material. Another test is a vibration analysis for rotational components. This research draws final conclusions from these test analyses and recommends whether the designed model is under safety condition in terms of mechanical structure.

하드웨어, 소프트웨어 및 서비스산업 간의 연결에 관한 연구 : 창원공단을 중심으로 Based on Chang-Won Industrial Complex

김경훈,정종윤 昌原大學校 産業經濟硏究所 1994 産經硏究 Vol.11 No.-