자동차 헤드램프 내의 에이밍 볼트의 풀림 해석 및 실험

문지승,백홍,박상신,박종명 한국트라이볼로지학회 2019 한국윤활학회지(윤활학회지) Vol.35 No.1

Self-loosening of bolts owing to external forces occurs in several machines that are clamped by bolts and nuts. This study focuses on the self-loosening of the aiming bolt of the head lamp in a vehicle. It is important to prevent the aiming bolt from self-loosening as it has a decisive effect on the angle of the head lamp. A nut clamped with a bolt, known as a retainer, is made of plastic and has a partial screw thread. In addition, a transverse load has a considerable impact on the self-loosening of a bolt. We concentrate on the self-loosening of a bolt by a transverse load. The aim of this study is to define the limits of the external force that loosen the bolt. Based on the above conditions, we derive a theoretical equation and develop a numerical analysis program that can calculate the limiting forces for self-loosening. To verify the developed program, we design a test device that can measure the self-loosening by applying sliding forces to the aiming bolt. Using this method, we can draw the following conclusions. First, the developed testing device is suitable to prove the theory for calculating the self-loosening force. Second, the equation confirms the relationship of bolt self-loosening between resistance torque and shear force. Finally, the equation obtains the minimum value of the resistance torque required to decrease the change in the angle of the head lamp, thereby improving the possibility of increasing the stability of the head lamp.

성인 편도수술 환자에서 정맥 내 자가 통증 조절법의 유용성

문지승,정성훈,구수권,문미진 대한이비인후과학회 부산,울산,경남 지부회 2015 임상이비인후과 Vol.26 No.2

Background:Post-tonsillectomy pain control is clinically important in otolaryngologic field. The aim of this study is to evaluate the efficacy and the safety of intravenous patients-controlled analgesia (IV PCA) after tonsillectomy in adults compare to non steroidal anti inflammatory drugs (NSAIDs). We also evaluate sexual differences in severity of postoperative pain and in response toward analgesics. Methods:In total, 40 patients underwent tonsillectomy due to frequent tonsillitis were enrolled. After subdivide patients into IV PCA group (Remifentanil 1 mg, 10 men and 10 women) and NASIDs group (Diclofenac sodium 75 mg, 10 men and 10 women), we compare postoperative pain during postoperative 3 days. Results:IV PCA group had significantly less pain at postoperative first, second and third day compared to the group using the NSAIDs (p<0.05). In IV PCA group, postoperative pain decreased more rapidly than NSAIDs group. Women complained more severe pain compared to men in both groups (p<0.05). Conclusions:IV PCA is more effective to control pain compared to NSAIDs in adult tonsillectomy patients. Women felt more intense pain than men. It is important find a suitable postoperative pain control method.

Comparison of Clinical Characteristics and Effects of Modified Jaw Thrust Maneuver During Drug-Induced Sleep Endoscopy (DISE) between Positional and Non-Positional Obstructive Sleep Apnea Patients

문지승,구수권,김영중,이상훈,이호병,박근형,이상준 대한이비인후과학회 부산,울산,경남 지부회 2018 임상이비인후과 Vol.29 No.2

Background and Objectives:Positional OSAS is characterized by an apnea-hypopnea index (AHI) score >5, which, while sleeping in the supine position, is double that in non-supine position. This study was performed to compare the clinical characteristics of positional OSAS and non-positional OSAS patients, and the effects of the modified jaw thrust maneuver during drug-induced sleep endoscopy (DISE) between positional OSAS and non-positional OSAS patients. Materials and Methods:68 positional OSAS patients and 19 non-positional OSAS patients were included. They all underwent full-night polysomnography and DISE. The modified jaw thrust maneuver was introduced during DISE. Airway structural changes induced by the modified jaw thrust maneuver were evaluated and documented. Results:There were no statistically significant differences in Friedman stage or tonsil grade, body mass index, Epworth sleepiness scale (ESS) score, blood pressure, AHI, or obstructive pattern between the positional and non-positional OSAS patients. However, mean arterial oxygen saturation (SaO2), lowest SaO2, and total arousal index values were more severe in the non-positional OSAS patients. After introduction of the modified jaw thrust maneuver, retrolingual level obstruction showed a tendency toward a higher rate of airway opening in positional OSAS patients than in non-positional OSAS patients. Conclusions:The effects of a mandibular advancement device (MAD) can be estimated by carrying out a modified jaw thrust maneuver during DISE. The tendency toward a higher rate of airway opening in positional OSAS patients than non-positional OSAS patients in retrolingual level obstruction after jaw thrust maneuver introduced during DISE may be clinically important for MAD.

비익에 발생한 망상조직구증 1예

문지승,구수권,박근형,이화선 대한이비인후과학회 부산,울산,경남 지부회 2020 임상이비인후과 Vol.31 No.2

Reticulohistiocytosis is a rare form of histiocytosis that can affect the skin and other organs. There are two distinct forms of reticulohistiocytosis, reticulohistiocytoma and multicentric reticulohistiocytosis. Reticulohistiocytoma is a cutaneous condition characterized by a solitary, firm, dermal skin lesion of less than 1cm in diameter. It can be diagnosed by histopathologic examination and immunohistochemical stains. It can be treated with simple resection, and recurrence is rare. In this article, the authors experienced a case of single reticulohistiocytoma that occurred in the nasal vestibule and report it with literature review

쉘 모델링을 활용한 공기 포일 스러스트 베어링의 강성, 감쇠 해석

문지승(J. S. Moon),박상신(S. S. Park) 한국트라이볼로지학회 2019 한국트라이볼로지학회 학술대회 Vol.2019 No.4

자동차 헤드램프내의 에이밍 볼트의 풀림 해석 및 실험

문지승(J.S. Moon),백홍(H. Baek),박상신(S.S. Park),박종명(J.M. Park) 한국트라이볼로지학회 2018 한국트라이볼로지학회 학술대회 Vol.2018 No.10

쉘 모델링을 활용한 공기 포일 스러스트 베어링 해석 및 실험

문지승(J. S. Moon),박상신(S. S. Park) 한국트라이볼로지학회 2019 한국트라이볼로지학회 학술대회 Vol.2019 No.10

자동차 헤드램프내 체결부품사이의 마찰계수 실험장치 개발

백홍,문지승,박상신,박종명 한국트라이볼로지학회 2019 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.35 No.1

When slipping occurs between two materials, the coefficients of friction must be considered because these values determine the overall efficiency of the machine or slip characteristics. Therefore, it is important to find the coefficient of friction between two materials. This paper focuses on obtaining the coefficient of friction between an aiming bolt and a retainer located in the headlamps of a vehicle. This bolt supports the headlamp, and if the bolt is loosened by external vibration, the angle of the light will change and block the vision of pedestrians or other drivers. In order to study these situations, the coefficient of friction between aiming bolts and retainers needs to be measured. In addition, the coefficient of friction of materials used in the headlamp should be obtained. To determine these two factors, a new device is designed for two cases: surface-surface contact and surface-line contact. To increase reliability of the results, the device is designed using an air-bearing stage which uses compressed air as lubricant to eliminate the friction of the stage itself. Experiments were carried out by applying various vertical forces, and the results show that the coefficient of friction can be measured consistently. The procedure for designing the device and the results are discussed.

A Case of Nasal Swell Body (Septal Turbinate) Combined with Pneumatization of Perpendicular Plate of the Ethmoid Bone

구수권,정성훈,문지승,손현이 대한비과학회 2016 Journal of rhinology Vol.23 No.1

The “nasal swell body” (NSB) or septal turbinate is a distinct structure of the anterior nasal septum that is observed on endoscopic and radiographic examination. It is primarily a glandular rather than a venous formation that is comprised of septal cartilage, bone, and thick mucosal lining. It is commonly found in patients with symptoms of chronic sinusitis and allergic rhinitis, and is linked to septal deviation. Space occupying lesions of the septum such as tumors, mucoceles, and pneumatization of the septum can lead to anatomical and functional disorders such as nasal obstruction and sinusitis, while more serious clinical conditions can develop when these lesions are combined with the NSB. Recently, there has been emphasis on the functional aspects of the NSB. It is especially being emphasized for clinicians to pay attention to the NSB and its connection with the stuffy nose. We report an interesting case of the NSB combined with pneumatization of the perpendicular plate of the ethmoid bone causing severe nasal obstruction and repetitive sinusitis along with a literature review.

수술로써 치료한 일측성 상악동 병변 318예의 후향적 연구

이호병,이상훈,문지승,박근형,구수권 대한이비인후과학회 부산,울산,경남 지부회 2018 임상이비인후과 Vol.29 No.2

Background and Objectives:Unilateral maxillary sinus lesions are relatively common but may occur in variety of causes. Therefore, accurate diagnosis and appropriate treatment are needed. The aim of this study is to review patients with unilateral maxillary sinus lesion who underwent surgical treatment and to analyze causes and characteristics of unilateral maxillary sinus lesions with literature review. Materials and Methods:A retrospective chart analysis was completed on 318 patients with unilateral maxillary sinus lesions who underwent surgical treatment from January, 2008 through May, 2018. Clinical history and data such as age, sex, symptoms of initial, radiologic and dental finding, operation type were collected from medical record. Results:Patients mean age was 50.7 years with slight male gender dominance. Most common type was sinusitis (42.7%), followed by odontogenic sinusitis (22.3%) and fungal ball (19.5%). In particular, the most common cause of odontogenic sinusitis was post dental surgery such as implant. Middle meatal antrostomy (90.9%) was accounted for a great part of surgery underwent to patients. Patients complained of post nasal discharge (62.9%), nasal obstruction (40.9%) and odor smell(35.2%) most commonly. Periapical lucency (35.8%) was the most common in CT finding followed by implant perforation (17.3%) and oroantral fistula (12.3%) in odontogenic sinusitis. Conclusions:Unilateral maxillary sinus lesions are relatively common, but they are increasing recently with dental procedures such as implant surgery, and serious adverse effects due to malignant tumors or improper treatment may occur, so accurate diagnosis and treatment are needed.