경추 신경근병증에 대한 전방 터널링 수술 : 초기 32례에 대한 보고

조태현,송준혁,서중근,CHo, Tae-Hyun,Song, Jun-Hyeok,Suh, Jung-Keun 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.7

Objectives : Anterior tunnelling technique consist of anterior cervical fractional interspace decompression without fusion. This method provides sufficient space for adequate neuroforaminal decompression but avoids the need for fusion or fixation. We report early clinical results of 32 cases that underwent anterior tunnelling operation for treatment of cervical radiculopathy. Methods : This method is identical to conventional approach until the exposure of anterior cervical body and bilateral retraction of longus colli is made. A vertical window is then made at the vertebral bodies and disc space lateral to the insertion site of the longus colli. The window is deepened with drilling that follows a tunnelling fashion down to the compressive lesion. We analyzed clinical results from 32 patients who treated between December 1998 and August 2000. Results : Satisfactory results were obtained in 87% of the patients. Two patients required revision surgery. None revealed surgical spinal instability on last follow-up. Conclusion : Anterior tunnelling operation is an acceptable surgical option for the treatment of cervical radiculopathy. Its advantages are short hospitalization, minimal postoperative discomfort, and technical feasibility.

양궁화살에 의한 두부 관통상 1례 - 증례보고 -

조태현,송준혁,김명현,박향권,김성학,신규만,박동빈,Cho, Tae-Hyun,Song, Jun-Hyeok,Kim, Myung-Hyun,Park, Hyang-Kwon,Kim, Sung-Hak,Shin, Kyu-Man,Park, Dong-Been 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.11

Apenetrating head injury by an arrow is extremely rare being only two cases reported in the literature. We report a case of 12-year-old boy who presented with an arrow lodged at the posterior fossa through nasal nostril. He was slightly drowsy, but neurologically intact except a sixth nerve palsy in the left eye. Brain CT showed no intracerebral hemorrhage. The arrow was entered through the right nostril and the tip was stucked in the left cere-bello-pontine angle through the sphenoid sinus. We removed the arrow without craniotomy since the tip was verified smooth and no cerebral arteries were in contact with the arrow. The patient recovered well without any significant complications. The sixth nerve palsy resolved completely after six months. The verification of the shape of the offending material, a retrograde removal of the arrow in the direction of its line of trajectory, and an identification of adjacent cerebral arteries seem to be important in the management of this type of injury.

Ti/Al/Ti 을 S/D 전극으로 이용한 용액공정 IGZO TFT의 전기적 특성 분석

조태현(Cho Tae Hyun),문국철(Kook Chul Moon),김용상(Yong-Sang Kim) 대한전기학회 2024 대한전기학회 학술대회 논문집 Vol.2024 No.10

에너지/환경 : 탄소 나노튜브를 함유한 나노유체의 열전도도 증가

조태현 ( Tae Hyun Cho ),박상도 ( Sang Do Park ),이영석 ( Young Seak Lee ),백일현 ( Il Hyun Baek ) 한국화학공학회 2004 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.42 No.5

효율적인 탐색을 위한 강화학습에서의 분포형 섭동 연구

조태현(Tae Hyun Cho),한승엽(Sung Yeob Han),이희수(Hee Soo Lee),이경재(Kyung Jae Lee),이정우(Jung Woo Lee) 한국통신학회 2022 한국통신학회 학술대회논문집 Vol.2022 No.2

분포형 강화 학습(Distributional Reinforcement Learning; DRL)은 확률적 환경에서 보상 분포(return distribution)를 학습하는 것을 목표로 한다. 학습된 보상 분포에는 환경의 확률에 대한 다양한 정보가 포함되어 있으므로, 이전 연구에서는 불확실성에 직면한 낙관론(Optimism in Face of Uncertainty; OFU)을 따르는 표준 편차와 같은 통계량에 의존해왔다. 이러한 선행연구는 위험추구(risk-seeking)와 회피(reverse) 방법으로 나뉘는데, 이와 같은 방법은 위험에 대한 일방적인 경향이 있다고 볼 수 있으며, 의도하지 않게 수렴을 방해하게 된다. 이 논문에서는 위험 중립적인 최적정책에 도달하기 위해 위험 기준을 무작위화하여 탐색하는 새로운 분포형 강화학습을 제안한다. 첫째, 행동 선택에서 위험 측도를 왜곡하여 섭동형 분포 벨만 최적성 연산자를 제공한다. 둘째, 약한 수축 특성(weaker contraction property)을 이용하여 제안한 방법의 수렴성과 최적성을 보장한다. 우리의 이론적 결과는 제안된 방법이 편향된 탐색에 속하지 않고 최적의 보상 분포로 수렴하는 것을 보장한다. 마지막으로 우리의 방법이 Atari 게임을 포함한 다양한 환경에서 기존의 다른 분포 기반 알고리즘보다 성능을 비교할 것이다.

산업별 시장점유 1위 감사인과 감사인 재선임

조태현(Cho, Tae-Hyun) 글로벌경영학회 2018 글로벌경영학회지 Vol.15 No.4

This paper investigates whether the biggest industry-market-share auditors are associated with auditor changes, given the prior studies arguing that audit quality of the biggest industry-market-share auditors is lower than other auditors. The probability of auditors change of the biggest industry-market-share auditors may be less than the other auditors due to either higher audit quality or client-friendly audit allowing more earnings management. Continued concern on audit quality and the reformed External Audit Law requiring periodical auditor designation raise doubt of low quality of industry leading auditors. I performed logit regression analysis for the sample of 9,868 firm-year observations for the listed firms, and 5,267 firm-year observations where the clients are audited by Big 4 auditors, for the 1996-2013 time period. My results indicate that the biggest market-share auditor by industry is associated with lower probability of auditor changes. My results also hold across the sample clients audited by Big 4 auditors. Lower probability of auditor changes for the biggest industry-market-share auditors might be resulted from higher audit quality of the auditors. But lower audit quality allowing earnings management, combined with efforts to maintain market share might lead to lower probability of auditor changes, given the prior studies reporting lower audit quality of the biggest market-share auditors. Prior studies argued lower audit quality of the biggest industry-market-share auditors due to acceptance of low audit fee from the fear of loosing market share. Under the less strict investor protection, the biggest market-share auditors might not have sufficient incentives to enhance audit quality in Korea.

회계의 보수성으로 측정한 산업별 시장점유 1위 감사인의 감사품질

조태현(Cho Tae Hyun) 글로벌경영학회 2016 글로벌경영학회지 Vol.13 No.4

Prior studies suggest a negative association between audit market concentration and audit quality, and furthermore the biggest industry-market-share auditors and audit quality in Korean audit market, where the Big 4 accounting firms operate four offices under the less strict legal liabilities as external audiors. This paper investigates whether the biggest industry-market-share auditors are associated with audit quality as measured by accounting conservatism based on the CScore developed by Kahn and Watts(2009) with a view to confirm the results of prior research reporting negative association of the biggest market-share auditors and audit quality measured by the absolute value of performance matched discretionary accruals by industry. The sample covers the 2005-2013 time period and consists of 3,661 firm-year observations for the listed firms. I also examine a sample of 2,502 firm-year observations where the clients are audited by Big 4 auditors. My results indicate that the biggest market-share auditor by industry is associated with lower audit quality, the likelihood of the client having lower Cscore. This implies that audit quality of the biggest market-share auditor by industry is lower than quality of the other auditors. In Korea, four engagement offices of Big 4 auditors cover the entire country. The biggest industry market share auditors could have more negative effect to audit quality due to acceptance of low audit fee from the fear of loosing market share. Under the less strict investor protection, the biggest market-share auditors simply do not have incentives to enforce high quality earnings and risk dismissal by their client in Korea. Thus my findings refute the view audit quality of the biggest market share auditors is higher as a industry specialist auditors. My results also hold across the sample clients audited by Big 4 auditors. This paper explains why audit quality of the big size auditors and industry specialized auditors are not higher than audit quality of other auditors in Korea.

태양광 시스템에서의 다층신경회로망기반 납축전지 잔존용량추정 알고리즘

조태현(Tae-Hyun Cho),황혜린(Hye-Rin Hwang),김범수(Berm-Soo Kim),이인수(In-Soo Lee) 한국정보기술학회 2017 Proceedings of KIIT Conference Vol.2017 No.12

종교인 소득 과세반대논리에 대한 타당성 분석 및소득세법 개선방향

조태현(Tae Hyun Cho),나 영(Young Na),육지훈(Jee Hoon Yuk) 글로벌경영학회 2018 글로벌경영학회지 Vol.15 No.2

The clergy s income was not taxed without any explicit exemption clauses under the connivance or assistance of tax authorities in the past several decades. Implementation of the Income Tax Act amendments of 2015 was delayed with effect from January 1, 2018 apparently due to the tax resistance. Prior studies pointed out several issues including unfairness of taxation between clergies and general tax payers, and between low income clergies and high income clergies and also optional obligation of income tax withholding. The purpose of this study is to examine the ground of objections raised in the process of the enactment of the clegy s income tax law, which led to the amendments with those issues above. This study also compare the tax regime of religious entities in Germany with the Amendment of 2015. Furthermore, this study suggests improvement directions on related income tax laws so that taxation of the clergy’s income in Korea is settled effectively. Our findings include that the law makers focused on the introduction of taxation of clergy s income and considered the tax resistance from religious organizations. Our study was not able to find any validity at all to objections raised to the taxation of clergy s income. The comprehensive review of German tax system also clarified that the separation of church and state in the political system does not mean tax exemption of clergy and need to have a initial and continuing assessment as to whether various religious organizations serve public interests for the tax exemption. In particular, this study suggests the fundamental amendment on income tax law for which is needed in that the law should rule the clergy’s income to be earned income rather than other income. It seems that a future study on improvements of accounting transparency of religious organizations for effective settlement of clergy’s income taxation will be performed consistently.

공업화학 촉매 / 반응공학 / Ag 함유 프리커서 핏치의 용융방사

조태현(Tae Hyun Cho),김선영(Sun Young Kim),조규행(Kyu Haeng Cho),유승곤(Seung Kon Ryu) 한국화학공학회 2000 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.38 No.3

To prepare silver-containing carbon fibers, silver nitrate was added to pitch and melt-spinning was performed. Silver nitrate was added by two different methods. One was the addition of it to raw pitch before reforming and the other was added to reformed pitch. The optimum spinning conditions were investigated by changing the spinning temperature, pressure, and winding speed. When silver nitrate was added to raw pitch, the softening point, viscosity, and spinnability of the reformed pitch were similar to those of non-silver-containing pitches. Because the decomposition of AgNO₃was occurred during the reforming. The spinnability and productivity of this pitch were good at 335℃. When silver nitrate was mixed to reformed pitch, the softening point and viscosity of mixed pitch increased in proportion to the amount of silver nitrate and the best spinning temperature was 345℃. Ag was uniformly distributed in the carbon fibers by installing the wire mesh in the spinneret.