단파장 자외선(254nm)에 노출된 고밀도 폴리에틸렌 수지의 카르보닐 지수(CI)와 기계적 물성 변화의 관계에 관한 연구

김창환 ( Chang Hwan Kim ),신진용 ( Jin Yong Shin ) 한국공업화학회 2013 공업화학 Vol.24 No.2

This paper studied the possibility to predict a mechanical property variation from changes in created carbonyl bands by irradiating the surface of high-density polyethylene with short-wavelength ultraviolet radiation of 254nm to induce a fast chemical degradation. The meaning of this study lies in checking whether a mechanical property change with the same chemical property as the induced optical deterioration is caused by using a UVC lamp with high photon energy instead of optical deterioration via xenon arc light source and outdoor exposure test via natural sunlight requiring a long time. The mechanical strength of high-density polyethylene checked by a tensile test and a creep destruction test showed a similar tendency with CI changes. In particular, the yield strength and elongation had a close relationship with the exposure time to ultraviolet radiation. Accordingly, this paper presented a method to grasp the mechanical property change outdoors requiring a long time more fast through the relationship between the mechanical property change and the carbonyl index using a UVC lamp causing the fast surface degradation.

後鼻漏를 主訴로 한 慢性 副鼻洞炎 患者의 治驗 1例

김창환,선영재,임웅경,김현기,Kim, Chang-hwan,Sun, Young-jae,Lim, Woong-kyoung,Kim, Hyun-gi 대한한방안이비인후피부과학회 2003 한방안이비인후피부과학회지 Vol.16 No.2

Paranasal sinusitis is a common disease in the otorhinolaryngology area. It is the change of inflammation at the mucous membrane which surrounds paranasal sinus. Chronic paranasal sinusitis is a chronic inflammation disease with purulent, mucous rhinorrhea, postnasal drip and cough. The attacked period continues above three months and it repeats exacerbation and remission. We diagnosed and treated an outpatient who complains postnasal drip of chronic paranasal drip of chronic paranasal sinusitis based on the Oriental medical theories and had good result.

안면신경마비에 대한 안륜근 미소안면침 증례보고

조아름,김지현,주경옥,원재선,김창환,Cho, Ah-Reum,Kim, Ji-Hyun,Chou, Ching-Yu,Won, Jae-Sun,Kim, Chang-Hwan 대한한방안이비인후피부과학회 2010 한방안이비인후피부과학회지 Vol.23 No.2

Objective : This study was designed to evaluate the effect of Miso Facial Acupuncture on Orbicularis Oculi muscle. Methods : Two men and four women with Facial nerve palsy were recruited. Miso Facial Acupuncture on Orbicularis Oculi muscle was performed two times a week for three weeks. The effects of the treatment were evaluated by H-B scale, Y-system and clinical symptom. Results : Before treatment with Miso Facial Acupuncture, three patients showed H-B scale improvement and the other three patients had no change. and four patients showed Y-system improvement and the other two patients had no change. In six cases, the patients had improvement in clinical symptom related with Orbicularis Oculi muscle function. Conclusion : Miso Facial Acupuncture on Orbicularis Oculi muscle showed significant improvement in facial nerve palsy.

하지길이균차에 대환 임상평가와 치료

김창환,김종덕,Kim, Chang-Hwan,Kim, Jong-Deog 척추신경추나의학회 2004 대한추나의학회지 Vol.5 No.1

Objectives : Visual check and X-ray are commonly used by chiropractors to estimate ieg length inequality, This study have three categories: diagnosis for anatomic leg length inequality; difference between anatomic and functional leg length inequality; theraphies for anatomic or functional leg length inequality. Methods : We referred to a PubMed site by using word of 'leg length [JU] J Manipulative Physiol Ther', only items with abstracts. Results : We searched 26 articles in J Manipulative Physiol Ther with the key word-Ieg length. Conclusion : 1. Radiographs were most accurate and commonly used by chiropractors to measure anatomic leg length inequality, clinically wood block, tape measure, visual check are acceptable. 2. There was no article about difference between anatomic and functional leg length inequality. 3. Heel lift was commonly used with conservative theraphy for anatomic leg length Inequality. 4. Chiropractors have not yet proved that the supposed positive effects are a result of a reduction of subluxation, The detection of the manipulative lesion in the sacroiliac joint depends on valid and reliable tests, Because such tests have not been established, the presence of the manipulative lesion remains hypothetical. Great effort is needed to develop, establish and enforce valid and reliable test procedures.

주사탐침현미경을 이용한 Si 표면 국부 산화피막 형성시 선 높이에 대한 탐침 전위, 편향 셋포인트, 탐침 속도의 영향

김창환,최정우,신운섭,Kim Chang-Hwan,Choi Jeong-Woo,Shin Woon-Sup 한국전기화학회 2006 한국전기화학회지 Vol.9 No.2

본 연구에서는 주사탐침현미경을 이용한 Si 표면의 국부 산화피막 형성에 있어서, 탐침이 움직이면서 생기는 $SiO_2$의 일차원적인 선의 높이가 탐침 전위, deflection setpoint, 탐침 속도에 의해 어떻게 영향을 받는지 고찰해 보았다. -3 V 보다 작은 탐침 전위에서는 국부 산화피막 형성이 관찰되지 않았으며 -3 V 보다 큰 탐침 전위에서는, 탐침 속도가 $1{\mu}m/s$일 때, 1 V씩 증가함에 따라 0.47nm의 비율로 선의 높이가 높아졌다. Deflection setpoint는 탐침이 가하는 기계적인 힘의 표지가 되는데, $12\sim18nN$ 정도의 힘이 가해지지 않으면 국부 산화피막 형성이 관찰되지 않았다. 그 이상의 힘이 가해져야 국부 산화피막 형성이 관찰되는데 이때 선의 높이는 기계적인 힘과 무관하였다. 탐침 속도가 빨라짐에 따라 선의 높이는 낮아졌으나, 탐침 전위가 -5V인 경우, 0.7nm 이하로 낮아지지는 않았다. The effects of tip voltage, deflection setpoint, and tip velocity on height of $SiO_2$ line drawn by local anodization on Si wafer using scanning probe microscope were investigated. No local anodization was detected at smaller than -3 V of tip voltage. The line height increased at rate of 0.47 nm/V when the tip voltage is stronger than -3 V at $1{\mu}m/s$ tip velocity. From deflection setpoint, mechanical force between tip and substrate could be calculated and the threshold farce was $12\sim18nN$. The height of anodized $SiO_2$ lines is independent of the magnitude of force above the threshold force. The line height decreased as increasing the tip velocity and limited to 0.7 nm at -5 V tip voltage.

디지털 치의학의 과거와 현재 그리고 미래

김창환,Kim, Chang Hwan 대한심미치과학회 2015 Journal of the Korean Academy of Esthetic Dentistr Vol.24 No.1

치과계에서 캐드캠이 보급되면서 본격적으로 사용한 지 15년이 넘었다. 코핑 정도의 역할에서 구치부 전부관으로 확대되었고, 최근에는 전치부에서도 많이 사용하는 추세이다. 장비의 발전도 비약적이었지만 지르코니아 블록의 발전이 가장 많이 이루어졌다. 개개인의 능력이나 경험 차에 의해 차이는 있을 수 있겠지만, 도재를 올리지 않고 지르코니아에 컬러링만으로도 얼마든지 색을 표현 할 수 있다. 또한 캐드 디자인 만으로도 표면의 질감을 표현하는 것에 우리가 알고 있는 만큼 가능하다. 본 논문에서는 이러한 디지털 치과학의 변천과정을 정리해 보고자 한다. Since its introduction to the dentistry, the CAD/CAM technology has been used over fifteen years. The application of CAD/CAM started from coping fabrication, expanded to the posterior full crown, and anterior restoration manufacture has also become widespread recently. While the development of machine was rapid, the advance of zirconia block was the fastest. Although some differences exist among individuals, the various natural tooth color can be expressed through the zirconia coloring itself without porcelain build up. And the texture characteristics can be reproduced just by CAD design. In this article, the development history of digital dentistry was summarized.

차세대 수동 광네트워크 기술

김창환,Kim, Chang-Hwan 한국광산업진흥회 2003 광산업정보 Vol.17 No.-

방송.통신 융합 서비스 동향

김창환,Kim, Chang-Hwan 한국정보통신집흥협회 2003 정보화사회 Vol.163 No.-

향후 2~3년간 통신 기술과 방송 기술의 융합 시도는 급속히 가속화될 것으로 보인다. 이 같은 기술 통합은 서비스간 융합으로 나타나 단기적으로 각각의 사업자는 가입자 확보를 위해 치열한 경쟁을 벌일 것이며, 방송.통신망의 디지털화 완성에 의한 망의 융합화가 더욱 진전돼 궁극적으로는 통합형 비즈니스 모델로 귀결될 것으로 예측된다.

농외소득개발저책의 현황과 장기발전방향

김창환,Kim, Chang-Hwan 한국조경수협회 1991 造景樹 Vol.5 No.11

이상경상돌기증의 치험례

김창환,김은관,박효상,박노부,이용오,Kim, Chang-Hwan,Kim, Eun-Goan,Park, Hyo-Sang,Park, No-Boo,Lee, Yong-Oh 대한악안면성형재건외과학회 1994 Maxillofacial Plastic Reconstructive Surgery Vol.16 No.3

Styloid process is a slender pointed bone of variable length, which project downward, forward, and slightly medialward from the posteroinferior portion of the tympanic part of the temporal bone. Embryologically, the styloid process is derived from Reichert's cartilage, a structure of second branchial arch origin. Most patients with elongated styloid process remain asymptomatic, but some patients complain pain and sensation of foreign body in the throat, dysphagia, dysphonia, referred otalgia. Recently, we have experienced a case of elongated styloid process in a fifty-nine year old man. He had been suffered from Rt. side sore throat, headache and pharyngeal discomfort during head movement. Through various X-ray examination, Xeroradiography, and palpation of tonsillar fossa, elongated styloid process on Rt. side was confirmed. Under the general anesthesia, it was successfully removed out via transoral approach technique, described by Eagle. The resected styloid process was 2.5cm in it's length and he was freed from the symptoms without further complication.