• Medical Lasers
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• 제9권2호
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• pp.103-109
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• 2020

Transoral microsurgery has come a long way as a go-to surgical intervention technique for head and neck cancers. This minimally invasive procedure had gained acceptance through comparative clinical studies against radical neck surgical procedures, radiotherapy, and chemotherapy. Laser technology has vastly improved the oncological outcomes of this procedure and brought about an appreciation of transoral laser surgery (TLM) as a mainstay for re-sectioning malignant tumors along the throat. As an established procedure, TLM has undergone several upgrades regarding the different energy devices used for cutting, ablation, and hemostasis. Continued advances in automation have eventually led to surgical robotics, resulting in the emergence of transoral robotic surgery (TORS) as a viable advanced alternative for TLM. Similarly, expansions and enhancements (image-based guidance, fluorescence spectroscopy, and advanced robotic system) have also been investigated as potential upgrades for TORS. This paper reviews a selection of publications on the significant technological advancements to TLM and TORS over the past five years.

• Medical Lasers
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• 제9권2호
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• pp.134-141
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• 2020

The use of stem cell therapy to treat various diseases has become a promising approach. The ability of stem cells to self-renew and differentiate can contribute significantly to the success of regenerative medical treatments. In line with these expectations, there is a great need for an efficient research methodology to differentiate stem cells into their specific targets. Photobiomodulation (PBM), formerly known as low-level laser therapy (LLLT), is a relatively non-invasive technique that has a therapeutic effect on damaged tissue or cells. Recent advances in adapting PBM to stem cell therapy showed that stem cells and progenitor cells respond favorably to light. PBM stimulates different types of stem cells to enhance their migration, proliferation, and differentiation in vitro and in vivo. This review summarizes the effects of PBM on targeted differentiation across multiple stem cell lineages. The analytical expertise gained can help better understand the current state and the latest findings in PBM and stem cell therapy.

• 대한두경부종양학회지
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• 제12권2호
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• pp.206-211
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• 1996

On 147 patients with early laryngeal cancer undertaken surgery or radiation therapy at Seoul National University Hospital from January 1987 through December 1994, retrospective analysis with reviewing the medical record was performed. The number of recurred cases was twenty six. The recurrence rate was higher in the cases with radiation therapy than in those with surgical therapy. And the recurrence rate was remarkable in the cases with T2 in supraglottic cancer and in those with T1 in glottic cancer. Of the patients undertaken surgery, recurrence rate was higher in the patients with laser operation than in those with other procedures. It was, however, lower in the patients with laryngofissure with cordectomy than in those with other surgical techniques. The overall three year disease free survival rate was 72 % in early laryngeal carcinoma.

• 항공우주기술
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• 제4권2호
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• pp.60-64
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• 2005

과학기술위성 2호의 주요 임무는 주 탑재체인 마이크로웨이브파 라디오미터(DREAM: Dual-channel Radiometers for Earth and Atmosphere Monitoring)개발, 부 탑재체인 레이저 반사경(SLR: Satellite Laser Ranging) 개발, 그리고 위성체 핵심기술 선행연구를 위한 Frame-Type 위성구조체, 복합소재 태양전지판, Dual-Head 별추적기, CCD 태양센서, 펄스형 플라즈마 추력기, 소형 탑재 컴퓨터 및 고속 X-band 송신기 개발 등을 포함한 100kg급 저궤도 소형위성 개발이다. 본 논문에서는 과학기술위성 2호 시스템에 대하여 설명을 한다. 과학기술위성 2호의 시스템 정의 및 기본적인 운영개념, 과학기술위성 2호의 주 탑재체인 마이크로웨이브파 라디오미터, 부 탑재체인 레이저 반사경, 그리고 이들을 지원하기 위한 위성본체 등을 포함한다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1423-1426
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• 2008

This paper describes current work regarding two EC funded projects, MUTED and HELIUM3D whose objective is to produce an autostereoscopic display system which is well suited to domestic television applications. Both of these projects have common roots in a previous EC funded project (ATTEST) and both employ laser illumination and viewer head tracking.

• 한국정밀공학회지
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• 제20권3호
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• pp.187-193
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• 2003

This paper presents an on-machine measurement method of flatness error fur surface machining processes. There are two kinds of on-machine measurement methods available to measure flatness errors in workpieces: i.e., surface scanning method and sensor scanning method. However, motion errors are often engaged in both methods. This paper proposes an idea to realize a measurement system of flatness errors and its rigorous application for estimation of motion errors of the positioning system. The measurement system is made by modifying the straightness measurement system, which consists of a laser, a CCD camera and processing system, a sensor head, and some optical units. The sensor head is composed of a retroreflector, a ball and ball socket, a linear motion guide unit and adjustable arms. The experimental .results show that the proposed method is useful to identify flatness errors of machined workpieces as well as motion errors of positioning systems.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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• pp.777-783
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• 2001

This paper is mainly concerned with the state of the practical developments of a constants PWM bridge type resonants DC-DC suitable converter for Nd:YAG Laser with a Microprocessor. (PIC16C54 & 8051) The use of IGBT power supply with feedback control of flashLamp currents imparts a advantages to Nd:YAG Laser for materials processing. these include the alility to tailor the pulseshape and modify pulse parameters on a pulse- by pulse basis. And Correct choice of pulseshape can enhance the repeatability of the process. as higher power IGBT became available, act ive pulseforming power supplies will find greater user in deep hole drilling machine By Using certain control tecniques, utililized in designing Pic16c54 from Microchip technology and Intel 8051, also Mornitoring from Microsoft Visual Basic 5, And it allowed us to designed and fabricate ahigh repel it ion rate and high power(HRHP) pulsed Nd:YAG laser system, As a result of that, the current pulsewidth could be contort led 200s to 350s(step 50s) , and the pulse repetition rate could be adjusted 500pps to 1150pps. In addition, in the case of one laser head consisting of a Nd:YAG laser rod and two flashlamps , the maximum laser output of 240w was produced at the condition of 350s and 1150pps, and that of about 480w was generated at the same condition when two laser heads were arranged in cascade.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.35-44
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• 2009

The purpose of this paper is to describe experimental results about the T-joint welding of the high power continuous wave (CW) fiber laser for SAPH steel plate for seat frame of car. The seat rail is a part of seat frame of cars. The assembling method is mostly fix up using a bolt and nut. But this assembling method has many demerits in productivity such as increasing work process and material cost. This paper presents an experimental study about Laser T-Joint weldability of seat rail. Laser welding has many advantages in lightness and saving material costs of seat frame. The laser beam was moved along the work pieces by six axis robot with process optical fiber. The laser beam is focused with a welding head within incident angle $15{\sim}45^{\circ}$ for the purpose of the T-joint welding through two side full penetration. The range of the root gap size is less than ${\leq}0.4mm$. Optical microscopy SEM were performed to observe the micro structures and determine the structures of welded zone.

• 대한기관식도과학회지
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• 제4권2호
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• pp.159-164
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• 1998

The developmental and subsequent addition of laser technology to existing surgical techniques offered new and exciting Possibilities for improving traditional endoscopic operations and expanding the scope of the specialty of otolaryngology-head and neck surgery. Lasers were found to be Precise, but potentially dangerous, surgical instruments whose use was associated with certain distinct and unprecedented advantages, but also with many unique and potentially serious, and sometimes catastrophic complications. The Purpose of this study was to evaluate the of elation technique of $CO_2$laser, kinds of anesthesia, equipments of operating room, and education of medical staff. Four hundreds 4 cases of $CO_2$laser laryngeal microsurgery were reviewed for the safety of $CO_2$laser in laryngeal microsurgery. Vocal polyp (46,3%) was the most common pathology in our cases. The others were vocal nodule, Reinke`s edema, epiglottic cyst, laryngeal granuloma, laryngeal papilloma, intracordal cysts, laryngeal tuberculosis, laryngeal web, laryngotracheal stenosis, and laryngeal cancer. Following complete equipment controls, treatment area controls, maintenance, service and procedural controls, personel protective equipment, and warning signs, no complications were found in our cases. In conclusion, laryngeal microsurgery with $CO_2$laser could be done safely without complication if complete preoperative preparation and education of medical staff preceded.

• 대한후두음성언어의학회지
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• 제32권3호
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• pp.118-123
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• 2021

The pulsed photoangiolytic 532-nm potassium-titanyl-phosphate (KTP) laser has emerged in recent years as an efficacious treatment modality for vocal fold lesions. It also has broadened the indications for other laryngeal laser surgery. Features of KTP laser that it is a fiber-based delivery system and its energy is selectively absorbed by oxyhemoglobin make it suitable for office-based laryngeal procedures. An office-based KTP laser surgery provides an alternative management option for benign laryngeal diseases and can be performed comfortably under flexible endoscopic guidance which is placed through the nose of a fully awake patient. Office-based laryngeal surgery with a KTP laser can alleviate the need for general anesthesia. However, there are some limitations to apply due to reduced visual precision and the fact that the vocal folds are moving during procedures. Clinicians should carefully weigh the advantages and disadvantages of office-based procedures before a treatment option is selected. Patient selection and standardized laser energy parameters may help in decreasing complications and improving the treatment results.