파워스티어링 호스 누유 개선에 관한 연구

이종황(Lee Jong Hwang),정원욱(Jung Won Wook),박종원(Park Jong Won),임영한(Lim Yung Han) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

Generally, leakage in high pressure hose assembly can be determined by that hydraulic fluid falls down through fitting which is swaged with rubber hose. The leakage which is the failure phenomenon occurred often in hydraulic system was tried to prevent. In the case of methods which verify leakage paths in power steering hydraulic system equipped with high pressure hose assembly, three types of leakage paths which can be seen by cutting the swaging part can be generally experienced. However, it was difficult to find out leakage paths using power steering oil. In this study, four methods which are thermal burn image method, hole drilling method of fitting metal, white paint infiltration method, and fluorescent infiltration method were tried to introduce. Fluorescent infiltration method could verify leakage path with the unaided eye simply to hold the cutting swaging part closely to the ray of light. Reappearance test methods in high pressure hose assembly, which are hole drilling, white paint infiltration, and fluorescent infiltration method, can be applied to find failure mode and to approval test before mass production of high pressure hose.

터널 시설물 내진성능평가 부실사례에 대한 고찰

이종한 ( Lee Jong-han ),황인상 ( Hwang In-sang ),김현국 ( Kim Hyun-guk ),손희재 ( Son Hee-jae ) 한국구조물진단유지관리공학회 2023 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.27 No.1

경주 · 포항지진 발생 이후 정부는 공공시설물의 내진성능 강화를 위하여 내진보강사업을 중점 추진 중이며, 「시설물안전법」이 전부개정(시행 ‘18.01.)되면서 준공 이후 내진성능평가를 받지 않은 시설물에 대하여 정밀안전진단 수행 시 해당 시설물의 내진성능평가를 포함하여 실시하도록 하고 있다. 이에 따라, 급격히 증가된 내진보강사업의 신뢰성에 대한 문제점이 지적되어 정부에서는 공공시설물의 내진보강사업 적정성 평가를 실시하고 있으며, 실시결과 다수의 내진보강사업에서 미흡한 사례가 조사되었다. 국토안전관리원 내진성능관리실에서도 정밀안전진단에 포함되어있는 내진성능평가 실시결과를 검토하고 있으며, 그중 터널 시설물에서 응답변위법 적용 시 속도응답스펙트럼 산정오류 사례를 소개하고 적정한 속도응답스펙트럼 산정방법에 대하여 고찰하고자 한다.

족저부에 발생한 건활막 연골종증(1예 보고)

황정수,정필현,강석,김종필,김영성,양철호,이종임,Hwang, Chung-Soo,Chung, Phil-Hyun,Kang, Suk,Kim, Jong-Pil,Kim, Young-Sung,Yang, Chul-Ho,Lee, Jong-Im 대한족부족관절학회 2009 대한족부족관절학회지 Vol.13 No.2

Tenosynovial chondromatosis is a multinodular cartilaginous proliferation that arises from the tenosynovial membranes. It is rare, benign neoplasm, most commonly affects the tendon of the wrist and hand. It is clinically important because of its high rate of recurrence with a unique histopathological pattern which not infrequently displays considerable focal cellular atypia and hypercellurality nevertheless it is benign, but it has not been well recognized because of its rarity. We report here a rare case of tenosynovial chondromatosis of the tendon sheath of flexor hallucis longus and flexor digitorum longus in plantar area.

업무수행이사의 이름 공시가 감사시간, 감사보수 그리고 직급별 감사시간에 미치는 영향

황지회 ( Jihoe Hwang ),이종은 ( Jong Eun Lee ) 한국회계학회 2021 회계학연구 Vol.46 No.4

2017년 회계정보의 투명성 향상을 위해 개정된 회계감사기준에 따라, 2018년 12월 15일 이후 종료되는 보고기간의 상장회사 재무제표에 대한 감사보고서에 업무수행이사의 이름을 기재해야 한다. 본 연구는 업무수행이사의 이름 기재가 의무화되기 전후인 2017년과 2018년의 상장기업을 대상으로 동 제도가 감사시간과 감사보수 및 감사팀 구성원의 직급별 감사시간에 미친 영향에 대해서 조사하고 있다. 주요 실증분석 결과는 다음과 같다. 먼저, 업무수행이사의 이름 공시 이후 총 감사시간과 총 감사보수는 유의적으로 증가하였다. 이는 감사보고서 실명제로 감사팀 전체가 감사품질 향상을 위해 노력하고 있음을 의미한다. 또한, 업무수행이사의 이름 공시 이후 총 감사시간 대비 업무수행이사, 전문가 및 품질관리검토자의 감사시간 비율이 유의적으로 증가하고 미등록공인회계사의 감사시간 비율은 유의적으로 감소하였으며, 등록공인회계사의 감사시간 비율은 유의적인 변화가 없는 것으로 나타났다. 이러한 실증분석결과들은 감사보고서 실명제로 증가된 책임성에 대해 업무수행이사 개인 뿐 아니라 회계법인이 전사적인 차원에서 대응하고 있음을 암시하고 있다. 연구의 강건성 확보를 위해 수행한 추가분석으로 (1)연구기간을 확대하여 실시한 분석, (2)이름 공시 전후를 동일 업무수행이사로 한정한 분석, (3)균형표본을 사용한 분석, 그리고 (4)감사노력의 다른 대용치를 이용한 분석이 있으며, 분석결과는 모두 본 연구의 결과와 질적으로 차이가 없다. 또한 전체표본을 Big4와 Non-big4로 나누어 업무수행이사의 이름 공시가 직급별 감사시간에 미치는 영향이 Big4와 Non-big4간에 차이가 있는지를 조사한 결과, 이름 공시 이후 Big4의 업무수행이사가 추가적으로 부담하는 위험의 정도는 Non-big4의 업무수행이사에 비해 낮은 것으로 나타났다. 회계투명성 제고를 위해 새롭게 도입된 규정의 효과성을 조사한 본 연구의 결과는 향후 관련 정책이 나아가야 할 방향을 설정하는데 도움이 될 것으로 사료된다. Audit firms are required to disclose audit engagement partner identification on audit reports by revised auditing standards of 2017. In this study, using Korean data for the years 2017 and 2018, before and after the adoption of the new standard, we examine the effects of engagement partner identification on audit hours, audit fees, and labor mix hours and find the following empirical results. First, audit hours and audit fees are significantly increased after the adoption of new disclosure requirement, suggesting that the audit team makes great efforts to manage potentially increased audit risk from the requirement. Second, in the result of using the ratios of labor mix hours, we also find that the ratios of the engagement partner's, specialist’s, and the quality reviewer's audit hours are significantly increased, indicating that not only individual engagement partners but also the accounting firms respond to the increased accountability and transparency of the audit report. The aforementioned empirical results are consistently robust across alternative sample and proxy: (1) expanded sample, (2) sample of controlling the effect of audit partner changes before and after adoption, (3) balanced sample, and (4) another proxies for audit efforts. In addition, we find that there is a differential effect of the disclosure requirement on labor mix hours between Big4 and Non-big4. More importantly, this study provides policy implications to the recent debate on the efficacy of the adoption of engagement partner identification requirement.

엔진 T-JOINT부 거동특성 분석을 통한 누유 개선

이종황(Lee Jong Hwang),박준식(Park Jun Sik),심양진(Sim Yang Jin),정원욱(Jung Won Wook) 한국신뢰성학회 2009 신뢰성응용연구 Vol.9 No.1

Due to the excellent durability of Timing Chain, it has been widely used for vehicle engine system. Unlike the timing belt, since the timing chain is operated with the metallic sprocket, the lubrication system is absolutely needed to get this system start. As frequeltly met at the field, the lubricant has a strong tendancy to leak out from the engine due to its severe operating environment. In this paper, results of investigation for thermal movement of aluminum chain cover were described to maximize the sealing ability which is despirately needed at the development stage of engine. Based on these results, some ideas for reproducing the leakage phenomenon and solving methods were proposed.

조기위암의 재발

안정식,방호윤,이종인,노우철,황대용,최동욱,백남선,문난모,최태인,Ahn Jung-Sik,Bang Ho-Yoon,Lee Jong-Inn,Noh Woo-Chul,Hwang Dae-Yong,Choi Dong-Wook,Paik Nam-Sun,Moon Nan-Mo,Choi Tae-Inn 대한위암학회 2001 대한위암학회지 Vol.1 No.3

Purpose: The prognosis for early gastric cancer (EGC) is favorable, and the 10-year disease-specific survival rate is reported to be around $90\%$. The absolute number of recurred EGC is too small to assess the risk factors, so recruitment of a large number of cases for statistical analysis is very difficult. We carried out this study to analyze the incidence and the patterns of recurrence of EGC and to identify the clinicopathological risk factors for recurrence of EGC. Materials and Methods: The authors retrospectively investigated the follow-up records of 1418 patients who underwent a curative resection for EGC from Jan. 1984 to Dec. 1999 at the Korea Cancer Center Hospital and analyzed them with special reference to cancer recurrence. Results: In this retrospective study of 1418 cases, 43 patients died of a recurrence of gastric cancer, and 105 patients died of unrelated causes. The five-year and the ten-year overall survival rates were $89.6\%$ and $81.7\%$, respectively, while the five-year and the ten-year diseasespecific survival rates were $96.5\%$ and $94.3\%$, respectively. The recurrence patterns of the 45 recurred EGC were hematogenous metastasis (19 cases), lymph node (L/N) metastasis (8 cases), locoregional recurrence (2 cases), peritoneal seeding (3 cases), and combined form (13 cases). The mean time interval to recurrence was 38.6 months, and the number of delayed recurred cases after 5 years was 10 ($22.2\%$). Of the clinicopathologic factors, depth of invasion, L/N metastasis, macroscopic type, lymphatic invasion, and vessel invasion, were significant risk factors in the univariate analysis. However, in the multivariate analysis, only L/N metastasis was an independent prognostic factor. Conclusion: Based on the results of this study, L/N metastasis is an independent prognostic factor. Thus, in patients with node-positive disease, adjuvant therapy might be considered, and long-term close follow-up might facilitate early detection and treatment of recurrent disease due to delayed recurrence.

충격 압력을 받는 파워스티어링 시스템의 고압호스 수명 예측

이기천(Gi Chun Lee),김형의(Hyoung Eui Kim),박종원(Jong Won Park),이종황(Jong Hwang Lee),정원욱(Won Wook Jeong),임영한(Young Han Lim),황권태(Kwon Tae Hwang),이영신(Young-Shin Lee),김재훈(Jae Hoon Kim) 대한기계학회 2010 大韓機械學會論文集A Vol.34 No.1

유압호스는 적용되는 압력에 따라서 저압, 중압, 고압으로 구분되어진다. 승용차의 파워스티어링 시스템은 저압부와 고압부 시스템으로 구분되어질 수 있다. 본 연구의 목적은 차량이 회전할 때 발생되는 충격압력이 고압호스부에 적용될 때 수명을 예측하는 것이다. 내부와 외부 조건을 조절하기 위해서 충격 압력과 작동유의 온도는 충격압력 시스템에서 제어되는 것이 필요하다. 충격압력 시험에서 압력과 작동유 온도만을 조절하여 얻은 결과는 고압호스의 수명을 예측하기 위한 조절형 가속수명시험을 적용하였으며, 또한 유한요소법으로 스웨이징부를 해석하였다. The hydraulic hose can be divided with the low pressure, the medium pressure, and the high pressure hose according to the applied pressure. The power steering system in a passenger car can be divided with the high pressure and the low pressure hose. This study deals with the life prediction for high pressure hose to be given impulse pressure which was generated in turning the car. To adjust with external and internal condition, impulse pressure and oil temperature need to be controlled with impulse test system. The result, which is only controlled with the pressure and oil temperature, adapted Calibrated Accelerated Life Test(CALT) method to predict the life of the high pressure hose and analyzed the swagging part by finite element method during the impulse test.

스마트 점자 인식 번역 시스템

김승현(Seung Hyun Kim),이석현(Seok Hyen Lee),이종창(Jong Chang Lee),황정식(Jung Sick Hwang),김수민(Su Min Kim) 한국통신학회 2020 한국통신학회 학술대회논문집 Vol.2020 No.11

하천환경의 생물학적 평가를 위한 저서동물지수(BMI)의 개발

공동수 ( Dongsoo Kong ),손세환 ( Se-Hwan Son ),황순진 ( Soon-Jin Hwang ),원두희 ( Doo Hee Won ),김명철 ( Myoung Chul Kim ),박정호 ( Jung Ho Park ),전태수 ( Te Su Jeon ),이종은 ( Jong Eun Lee ),김종현 ( Jong Hyun Kim ),김종선 ( Jon 한국물환경학회 2018 한국물환경학회지 Vol.34 No.2

The tolerance of Korean benthic macroinvertebrates to organic pollution has been analyzed since the early 1990s. However, considering the fact that there have been related studies carried out in some European countries since the early 20th century, the history of the research in Korea is very short and there is still much knowledge to supplement. We revised the saprobic valency, the saprobic value and the indicator weight value of 190 benthic macroinvertebrates taxa through the data of water quality and individual abundance collected from 7,086 sampling units in Korea from 2008 to 2014. The individual abundance of Uracanthella (Ephemeroptera) as a representative, one of the most common and abundant taxa in Korea, showed a typical lognormal distribution to 5-day biochemical oxygen demand (BOD₅) concentration, and a normal distribution to the class interval of BOD₅ concentration according to saprobic series. The value combining the mean individual abundance and the relative frequency of occurrence was a more efficient indicator value than that of each property alone. Benthic Macroinertebrates Index (BMI) was newly proposed as a modification of the saprobic index of Zelinka and Marvan (1961). BMI showed extremely significant correlation (determination coefficient r² > 0.6, n = 569 sites) with the concentration of BOD₅, and the coefficient was a little higher than those of the previous indices. Until now, there has been very little research on the assessment of biological integrity of benthic macroinvertebrates community in Korea. While continuing researches into improve the reliability of BMI, it is necessary to develop multimetric indices for evaluating the integrity, including the composition of species and functional guilds, and the richness and diversity of the community.

ESPI를 이용한 자동차 TPS 면외변형 계측

한상길(Sang-Kil Han),함효식(Hyo-Shick Ham),함상현(Sang-Hyun Ham),이종황(Jong-Hwang Lee),정원욱(Won-Wook Jung),이창희(Chang-Hee Lee),이상봉(Sang-Bong Lee),최성을(Sung-Eul Choi) 한국비파괴검사학회 2010 한국비파괴검사학회지 Vol.30 No.5

본 논문에서는 ESPI 방법을 이용하여 자동차 엔진의 핵심 부품인 TPS의 열변형력에 따른 변외변형을 측정하여 열변형 특성을 분석하였다. 높은 해상도의 CCD와 줌렌즈를 사용하여 부품의 검사영역을 가로 세로 각각 5cm로 최소화하였다. 주행거리가 다른 TPS 부품들을 4-step 위상이동법과 위상 연속화를 통해 변형량이 연속적으로 변하는 위상도를 얻었고, 3차원으로 변형의 모양과 크기를 나타내었다. 약 70℃의 온도를 유지하면서 TPS 부품에 열을 가한 경우 주행거리가 길어질수록 TPS 변형은 크게 측정되었고, 위로 볼록한 형태로 변형되었다. 그리고 내부결함이 있는 부품에서는 위상도에 불연속적인 무늬가 나타났고, 아래로 오목한 모양을 갖는 변형으로 나타났다. In this paper, we analyzed the characteristics of thermal deformation of the TPS which is a core part of engine in vehicle by measuring out-of-plane deformation using ESP!. Inspection area of a test piece was minimized to 5 cm by 5 cm by using a high resolution CCD and a zoom lens. 4-step phase shifting method was used along with phase unwrapping algorithm to get a continuous phase map, configurations and deformations were displayed as 3D images. When heating the test pieces while maintaining the temperature at about 70℃, the out-of-plane deformations were measured. The results showed that a test piece with longer distance traveled tends to show larger thermal deformation, we could observes a convex shaped deformation on the surface. The inner defect sample, we could monitor discontinuous pattern phase map, and a concave shaped deformation on the surface.