GPU를 이용한 위상 측정법의 가속화

김호중,조태훈,Kim, Ho-Joong,Cho, Tai-Hoon 한국정보통신학회 2017 한국정보통신학회논문지 Vol.21 No.12

최근 산업의 여러 분야에서 자동화 시스템이 발전함에 따라 3D 측정에 의한 물체의 높이 검사의 필요성이 점차 대두되고 있다. 여러 3D 측정 방법 중에서 본 논문에서 다루는 방법은 위상 측정법으로, 위상 측정법이란 프린지 패턴의 위상값을 이용하여 물체의 높이를 구하는 방법이다. 위상 측정법은 연산량이 많이 필요한 알고리즘이기 때문에 이를 효율적으로 해결할 방법이 필요하다. 본 논문에서는 이를 위해 NVIDIA에서 나온 CUDA를 사용할 것을 제안했다. 또 CUDA에서 제공하는 Pinned memory와 Stream을 사용할 것을 제안하였다. 이를 통해 정확도를 유지하면서 측정 속도는 크게 향상시킬 수 있었고 실험을 통해 성능을 입증하였다. Automation systems are evolving in many areas of industry in recent years. At the same time, the necessity of the height inspection of the object by the 3D measurement is gradually increasing. Among the various 3D measurement methods, this paper discusses phase measuring profilometry(PMP). The PMP is a method of obtaining the height of an object using the phase value of the fringe pattern. Since the PMP is an algorithm requiring a large amount of computation, a method for efficiently solving the problem is needed. In this paper, we propose to use CUDA from NVIDIA to solve this problem. We also propose using pinned memory and streams provided by CUDA. This can greatly improve the measurement speed while maintaining accuracy. Finally, we demonstrate the performance of the proposed method through experiments.

Fringe Projection Profilometry를 개선한 효율적인 3D 측정 기법

김호중,조태훈,Kim, Ho-Joong,Cho, Tai-Hoon 한국정보통신학회 2016 한국정보통신학회논문지 Vol.20 No.10

기술이 발전하면서 카메라를 통해 3D 측정을 하는 방법은 계속 발전되어왔고 최근에는 여러 주기의 fringe pattern을 이용한 측정 방법을 쓰고 있다. 본 논문에서는 여러 주기의 fringe pattern을 이용한 3D 측정 방법에 대한 기존 방법의 문제점을 제시하고, 이에 대한 해결 방안으로 기준면의 절대위상과 물체의 위상차를 이용한 물체의 절대위상을 구하는 방법을 제안한다. 이를 이용하면 새로운 물체에 대해서 매번 여러 주기의 fringe pattern을 조사하지 않고 물체의 절대위상을 얻을 수 있다. 따라서 제안하는 방법을 이용하면, 측정단계에서 취득하는 영상의 개수가 적기 때문에 보다 빠른 속도로 3D 측정을 할 수 있다. 실험을 통하여 제안하는 방법의 유용성을 보였다. As technologies evolve, diverse 3D measurement techniques using cameras and pattern projectors have been developed continuously. In 3D measurement, high accuracy, fast speed, and easy implementation are very important factors. Recently, 3D measurement using multi-frequency fringe patterns for absolute phase computation has been widely used in the fringe projection profilometry. This paper proposes an improved method to compute the object's absolute phase using the reference plane's absolute phase and phase difference between the object and the reference plane. This method finds the object's absolute phase by adding the difference between the reference plane's wrapped phase and the object's wrapped phase to the reference plane's absolute phase already obtained in the calibration stage. Through this method, there is no need to obtain multi-frequency fringe patterns about new object for the absolute phase computation. Instead, we only need the object's phase difference relative to the reference planes's phase in the measurement stage.

기도질환 환자의 치료기관지경술

김호중,Kim, Ho-Joong 대한기관식도과학회 2008 大韓氣管食道科學會誌 Vol.14 No.2

Surgical resection and reanastomosis has been the treatment of choice in patients with tracheobronchial stenosis. Recent development of bronchoscopic intervention has been replacing the role of surgery in these patients. After summarizing the upto date data of bronchoscopic intervention, the proper management of tracheobronchial stenosis will be presented. Bronchoscopic intervention would be much effective when performed under rigid bron- choscopy, due to the stable patients' condition and endoscopic view. The usual method of intervention includes ballooning, Nd-YAG laser resection, bougienation, mechanical airway dilatation, stenting and photodynamic therapy. Silicone stents are very effective in patients with tracheobronchial stenosis to maintain airway patency. Bronchoscopic intervention provided immediate symptomatic relief and improved lung function in most of patients. After airway stabilization, stents were removed successfully in 2/3 of the patients at a 12-18 months post-insertion. Less than 5% of patients eventually needs surgical management. Acute complications, including excessive bleeding, pneumothorax, and pneumomediastinum develops in less than 5% of patients but managed without mortality. Stent-related late complications, such as, migration, granuloma formation, mucostasis, and restenosis are relatively high but usually controlled by follow-up bronchoscopy. In conclusion, bronchoscopic intervention, including silicone stenting could be a useful and safe method for treating tracheobronchial stenosis.

열산화 처리된 Ti-Ag 합금의 세포적합성

김호중,오근택,이지환,김경남,한동후,Kim, Ho-Joong,Oh, Keun-Taek,Ee, Zi-Whan,Kim, Kyoung-Nam,Han, Dong-Hoo 대한치과보철학회 2004 대한치과보철학회지 Vol.42 No.4

Statement of problem: In its preceding work, change in surface characteristics were investigated in consideration that both microtopograpy and macroscopic configuration of implants surface are two of the most important factors, in that they can construct agreeable environment by raising surface energy, to affect osseointegration and biocompatibility explained by cell proliferation. Purpose: This study focused on examining cytocompatibility of dental implants materials Ti-Ag alloys, of which mechanical and electrochemical superiority to cp-Ti or Ti6Al4V were verified, in comparison with that of cp-Ti, and Ti6Al4V. Materials and methods: In this regard, MTT tests for L-929, the fibroblast connective tissues and cell proliferation tests for osteoprogenitor cells, MC3T3-E1 were performed on cp-Ti, Ti6Al4V, and Ti-Ag alloys following thermal oxidation according to appropriate heat treatment temperature(untreated, 400, 600, $800^{\circ}C$) and heat treatment duration(untreated, 0.5, 1, 4 hr). Results: The MTT tests on fibroblasts L-929 resulted in cell viability of over 90% in all experimental group entities, where, especially, the 100% of the viability for Ti-Ag alloys specimens accounted for the slightest adverse effect of ions release from those alloys on the cell. In MC3T3-E1 proliferation tests, the population of cells in the experimental group was roughly increased as experimentation proceeded, after two to four days. Proliferation showed highest viability for most of specimens, including Ti2.0Ag, treated at $600^{\circ}C$. Conclusion: In conclusion, it is the heat treatment temperature, not the duration that has considerable effects on thermal oxidation of specimens. Ti-Ag alloys treated at $600^{\circ}C$ proved to have the best surface morphology as well as cytocompatibility when compared with Ti or Ti6Al4V for short-term biocompatibility tests.

Occlusal Stress가 Cervical Abfraction에 미치는 영향

김호중,정문규,Kim, Ho-Joong,Chung, Moon-Kyu 대한치과보철학회 1996 대한치과보철학회지 Vol.34 No.2

In order to epidemiologically verify the tensile that cervical abfraction is developed from the tensile stress during lateral excursion, comparisons between the experimental group with cervical abfraction and the control group without cervical abfaction was made by exmining the occlusal wear and patterns from the dental cast. 1. The degree of occlusal wear in the experimental group with cervical abfraction was higher than that of control group without cervical abfraction.(p<0.05) 2. No significant difference in the occlusal wear pattern was found between the experimental group and the control group. 3. Higher degree of occlusal wear was found in the age group of abov 40 than that of below 40.(p<0.05) 4. There was a correlation between the degree of occlusal wear and the degree of cevical abfraction.(p<0.05) 5. There was a correlation between the age and the degree of cevical abfraction.(p<0.05) It can be concluded that occlusal stress is the etiologic factor of cervical abfraction, but no clear distinction was made between the relationship of tensile stress and cervical abfraction.

기도질환에서 실리콘 기도스텐트 치료

김호중,Kim, Ho-Joong 대한기관식도과학회 2004 大韓氣管食道科學會誌 Vol.10 No.2

Stenosing airway disease is classified as intraluminal obstruction, extrinsic compression, and malacia by the anatomical site of the lesion. Stenting therapy is indicated for symptomatic relief of life-threatening dyspnea caused by the last two types. Airway stents are made with metal mesh and/or silicone rubber, and currently more than 20 kinds of stent are available. Among many kinds of silicone stent, the Dumon stent is mostly widely used for benign and malignant airway stenoses, but general anesthesia and rigid bronchoscopy are needed for insertion. It can be removed when the stenosing airway disease subsides completely. In many clinical studies, most patients $(85-90\%)$ improved immediately after stenting, and procedure-related mortality was low $(<3\%)$ in experienced centers. Stent displacement, mucus impaction, and granulation tissue formation are potential complications. Stenting is one of many effective therapeutic modalities for stenosing central airway disease. Careful patient selection, experiences, and continuous development of new technology will bring better results.

상기도협착 환자에서 기도스텐트 치료

김호중,Kim, Ho-Joong 대한기관식도과학회 2009 大韓氣管食道科學會誌 Vol.15 No.2

굴곡성 기관지경하 전기소각술로 치료한 미만성 기관기관지형 유전분증

김호중 ( Ho Joong Kim ),고종훈 ( Jong Hoon Koh ),장명준 ( Myeong Jun Chang ),홍성훈 ( Sung Hun Hong ),김경환 ( Kyung Hwan Kim ),현인규 ( In Kyu Hyun ),이명구 ( Myoung Koo Lee ),정기석 ( Ki Suck Jung ) 대한결핵 및 호흡기학회 1995 Tuberculosis and Respiratory Diseases Vol.42 No.2

기도질환에서 실리콘 기도스텐트 치료

김호중 ( Ho Joong Kim ) 대한결핵 및 호흡기학회 2007 Tuberculosis and Respiratory Diseases Vol.62 No.2

감사인의 조세컨설팅 보수가 기업의 회계투명성에 미치는 영향

김호중 ( Ho Joong Kim ),김진욱 ( Jin Wook Kim ),김진태 ( Jin Tae Kim ) 아시아.유럽미래학회 2016 유라시아연구 Vol.13 No.1

본 연구는 감사인으로부터 비감사서비스 중 조세컨설팅을 제공 받는 기업을 대상으로 하여 감사인의 조세컨설팅 보수가 기업의 회계투명성에 어떠한 영향을 미치는지 분석하였다. 이를 위하여 본연구에서는 수정 Jones 모형에 의한 재량적 발생액과 성과대응 재량적 발생액 모형을 회계투명성에 대한 대용치로 하여 분석을 실시하였다. 2008년부터 2013년을 검증기간으로 한 분석결과는 다음과 같다. 첫째, 감사인의 조세컨설팅 보수는 기업의 이익조정의 대용치인 재량적 발생액과 유의한 관계를 가지지않는 것으로 나타났으나, 성과대응 재량적 발생액과는 유의한 양(+)의 관계를 가지는 것으로 나타났다. 이는 감사인의 조세컨설팅 보수가 증가할수록 기업의 이익조정이 증가한다는 것을 의미한다. 둘째, 감사인의 조세컨설팅 보수를 기준으로 보수가 높은 집단과 보수가 낮은 집단으로 각각 구분한 후 이익조정에 미치는 영향을 살펴본 결과는 다음과 같다. 재량적 발생액을 이익조정의 대용치로 한 결과를 보면 조세컨설팅 보수가 높은 집단 및 낮은 집단 모두 재량적 발생액에 유의한 양(+)의 영향을 미치는 것으로 나타났다. 그러나 성과대응 재량적 발생액의 경우 조세컨설팅 수수료가 높은 집단의 경우만 성과대응 재량적 발생액에 유의한 양(+)의 영향을 미치는 것으로 나타났다. 이와 같은 결과로 볼 때, 감사인이 피감사인에게 조세컨설팅 보수를 높게 지급할수록 감사인의 피감사인에 대한 경제적 의존도가 증가함으로써 회계투명성이 저하되는 것으로 판단된다. 따라서 기업의 이해관계자들은 동일한 감사인에게 감사서비스이외에 조세컨설팅을 수행하는 경우 이러한 조세컨설팅 수행 또는 조세컨설팅 보수가 감사인의 독립성을 저해할 수 있다는 것을 고려하여 의사결정을 해야 할 것이다. This study examines the relationship between non-audit fees and accounting transparency. In particular, we investigates the effect of auditor-provided tax consulting fees on accounting quality, proxied by modified Jones model-based discretionary accruals and performance matched discretionary accruals. The empirical results for the period of 2008-2013 are as follows. First, we find that auditor-provided tax consulting fees are significantly and positively associated with performance matched discretionary accruals, implying that firms with higher auditor-provided tax consulting fees are more likely to engage in earnings management. Second, we find that firms belongs to high tax fee group are positively associated with both modified Jones model-based discretionary accruals and performance matched discretionary accruals while firms belongs to low tax fee group are positively associated with modified Jones model-based discretionary accruals only. Overall, the results suggest that auditor-provided tax consulting impairs auditor independence, resulting in the deterioration of accounting transparency.