Causes and Predictive Factors Associated with "Diagnosis Changed" Outcomes in Patients Notified as Tuberculosis Cases in a Private Tertiary Hospital

Kang, Byung Ju,Jo, Kyung-Wook,Park, Tai Sun,Yoo, Jung-Wan,Lee, Sei Won,Choi, Chang-Min,Oh, Yeon-Mok,Lee, Sang-Do,Kim, Woo Sung,Kim, Dong Soon,Shim, Tae Sun The Korean Academy of Tuberculosis and Respiratory 2013 Tuberculosis and Respiratory Diseases Vol.75 No.6

Background: The aim of our study was to evaluate the "diagnosis changed" rate in patients notified as tuberculosis (TB) on the Korean TB surveillance system (KTBS). Methods: A total of 1,273 patients notified as TB cases on the KTBS in one private tertiary hospital in 2011 were enrolled in the present study. Patients were classified into three groups: "diagnosis maintained", "diagnosis changed" (initially notified as TB, but ultimately diagnosed as non-TB), and "administrative error" (notified as TB due to administrative errors). Results: Excluding 17 patients in the "administrative error" group, the "diagnosis maintained" and "diagnosis changed" groups included 1,097 (87.3%) and 159 patients (12.7%), respectively. Common causes of "diagnosis changed" were nontuberculous mycobacterial (NTM) disease (51.7%, 61/118), and pneumonia (17.8%) in cases notified as pulmonary TB, and meningitis (19.5%, 8/41) and Crohn's disease (12.2%) in cases notified as extrapulmonary TB. Being older than 35 years of age (odds ratio [OR], 2.18) and a positive acid-fast bacilli stain (OR, 1.58) were positive predictors and a TB-related radiological finding (OR, 0.42) was a negative predictor for a "diagnosis changed" result via multivariate logistic regression analysis in pulmonary TB cases. Conclusion: Because of a high "diagnosis changed" rate in TB notifications to the KTBS, the TB incidence rate measured by the KTBS may be overestimated. Considering the worldwide trend toward increased NTM disease, the "diagnosis changed" rate may increase over time. Thus, when reporting the annual TB notification rate in Korea, the exclusion of "diagnosis changed" cases is desirable.

Predictive Risk Assessment Using Cooperation Concept for Collision Avoidance of Side Crash in Autonomous Lane Change Systems

Hyunsoo Lee,Chang Mook Kang,Wonhee Kim,Woo Young Choi,Chung Choo Chung 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

We present an innovative approach to risk assessment using cooperation concept for collision avoidance of side crash for autonomous lane change system. The cooperation concept is proposed to check an available space in the target lane for lane change in a short period of the future. Before moving to the target lane, the ego vehicle needs to check whether the object vehicle is cooperative or not for the lane change. The object vehicles are indexed as cooperative driver (CD) or non-cooperative driver (NCD) through the conditions based on the relative longitudinal acceleration and the collision free time. If the object vehicle is CD, the ego vehicle moves toward the target lane within the original lane for the preparation of the lane change. The ego vehicle should keep its lateral position within the original lane until the situation for the lane change becomes safe. As soon as the risk assessment becomes safe, the lane change is performed. Therefore, lane change can be started in advance compared to the conventional methods. The proposed method was validated via computational simulation and experimental results.

Causes and Predictive Factors Associated with “Diagnosis Changed” Outcomes in Patients Notified as Tuberculosis Cases in a Private Tertiary Hospital

( Byung Ju Kang ),( Kyung Wook Jo ),( Tai Sun Park ),( Jung Wan Yoo ),( Sei Won Lee ),( Chang Min Choi ),( Yeon Mok Oh ),( Sang Do Lee ),( Woo Sung Kim ),( Dong Soon Kim ),( Tae Sun Shim ) 대한결핵 및 호흡기학회 2013 Tuberculosis and Respiratory Diseases Vol.75 No.6

Background: The aim of our study was to evaluate the “diagnosis changed” rate in patients notified as tuberculosis (TB) on the Korean TB surveillance system (KTBS). Methods: A total of 1,273 patients notified as TB cases on the KTBS in one private tertiary hospital in 2011 were enrolled in the present study. Patients were classified into three groups: “diagnosis maintained”, “diagnosis changed” (initially notified as TB, but ultimately diagnosed as non-TB), and “administrative error” (notified as TB due to administrative errors). Results: Excluding 17 patients in the “administrative error” group, the “diagnosis maintained” and “diagnosis changed” groups included 1,097 (87.3%) and 159 patients (12.7%), respectively. Common causes of “diagnosis changed” were nontuberculous mycobacterial (NTM) disease (51.7%, 61/118), and pneumonia (17.8%) in cases notified as pulmonary TB, and meningitis (19.5%, 8/41) and Crohn`s disease (12.2%) in cases notified as extrapulmonary TB. Being older than 35 years of age (odds ratio [OR], 2.18) and a positive acid-fast bacilli stain (OR, 1.58) were positive predictors and a TB-related radiological finding (OR, 0.42) was a negative predictor for a “diagnosis changed” result via multivariate logistic regression analysis in pulmonary TB cases. Conclusion: Because of a high “diagnosis changed” rate in TB notifications to the KTBS, the TB incidence rate measured by the KTBS may be overestimated. Considering the worldwide trend toward increased NTM disease, the “diagnosis changed” rate may increase over time. Thus, when reporting the annual TB notification rate in Korea, the exclusion of “diagnosis changed” cases is desirable.

논문 : 배당의 미래이익 예측력과 외국인투자자

강태구 ( Tae Goo Kang ),이창우 ( Chang Woo Lee ),남혜정 ( Hye Jeong Nam ) 명지대학교 금융지식연구소 2013 금융지식연구 Vol.11 No.3

본 연구는 배당의 미래이익 예측력이 외국인 투자자들의 지분율에 따라 어떻게 달라지는지 검증하였다. 일반적으로 배당지급은 기업의 미래이익을 예측하는 데 유용한 정보로 여겨지고 있으나, 이에 대한 실증연구결과들은 혼재되어 있다. 또한 배당의사결정과 관련된 연구들은 투자자들의 배당선호현상에 따라 기업의 배당의사결정이 영향을 받고 있음을 제시하고 있으며, 특히 우리나라의 경우, 배당의사결정에 외국인투자자가 미치는 영향이 매우 높게 나타나고 있다. 이는 특정투자자집단의 배당요구가 높은 경우, 기업의 배당의사결정이 미래이익에 대한 사적정보의 전달수단이기 보다는 단기적으로 배당에 대한 투자자들의 요구를 반영한 결과로 나타날 수 있음을 보여준다. 나아가 이러한 배당의사결정은 배당의 미래이익 예측력을 낮게 만들 것으로 예측된다. 본 연구는 배당의 미래이익 예측력을 재검증하고, 나아가 외국인지분율에 따라 배당의 미래이익예측력이 달라지는지 검증하였다. 먼저, 배당의 미래이익 예측연구들은 자기자본이익률(ROE)의 평균회귀(mean reverting)현상과 배당증가 또는 배당감소가 이익변화에 미치는 비대칭적 영향을 고려하고 있으나, 이익변화에 영향을 미치는 여러 가지 변수들을 통제하지 않고 있다. 따라서 본 연구는 선행연구에서 제시되고 있는 기업규모(SIZE), 성장성(SGR), 부채비율(LEV), 그리고 연도더미를 추가하여, 이를 통제하고 난 후에도 배당의 미래이익예측력이 여전히 존재하는지 검증하였다. 둘째, 배당의 미래이익 예측력이 기업의 배당의사결정에 영향을 미치는 특정집단에 의하여 달라지는지 검증하였다. 2000년부터 2007년까지 배당지급을 한 6,720 기업-년 표본을 대상으로 분석한 결과, 기본 모형뿐만 아니라 여러 통제변수를 포함한 모형에서도 우리나라 기업들의 배당변화는 미래 1년 뒤의 이익변화와 유의한 양의 관계를 나타냈으나, 미래 2년 뒤의 이익변화와는 유의하지 않았다. 또한 이익변화에 영향을 미치는 변수들을 추가한 모형의 설명력(R2=0.46)이 기본모형의 설명력(R2=0.28)보다 급격히 증가함을 알 수 있었다. 그러나 이러한 관계는 외국인지분율을 통제할 경우, 유의하지 않게 나타났다. 이는 기업의 배당의사결정이 미래전망에 근거하여 이루어지기보다는 특정투자자집단의 배당요구를 반영하는 수단으로 사용되고 있음을 보여준다. 즉 우리나라의 경우, 배당의사결정이 외국인투자자들의 배당요구를 반영하여 이루어짐을 알 수 있다. 본 연구는 대부분의 선행연구들이 외국인투자자와 배당성향간의 동시적인 관계에 대한 결과들을 제시한 반면에, 외국인투자자가 우리나라 기업들의 배당의사결정에 미치는 영향과 함께 배당의 미래이익예측력의 관점에서 살펴보았다는 점에 의의가 있다. This paper investigates whether the dividend payout predicts future earnings and the predictability varies depending on the proportion of investors. Specifically, this paper examines the effect of foreign investors on the relationship between dividend change and the predictability of future earnings in Korean firms. Reasoning from the hypothesis that dividend changes convey new information about a firm`s future profitability, a dividend increase is seen as a positive signal about the firm`s future earnings and profitability. However, the results from prior studies are controversial. Some papers have suggested that dividend changes would mean different things depending on a firm`s dividend policy and the motives behind its managers` decision to pay dividends. In addition, a firm`s governance is considered as one of important factors that affects dividend policy. In the Korean security market, foreign investors owned about 38% of the stock in 2007. As the percentage of foreign ownership had grown, many researchers have analyzed the effect of this ownership on dividend policy. However, prior studies found mixed results and have focused on the association between foreign investors and the level of the dividend or dividend change. They also suggest that predictability of dividend on future earnings is influenced by applied assumption on earnings and other factors like governance as well. We revisit the dividend signaling issue in the light of the catering theory of dividends suggested by Baker and Wurgler (2004). Lintner (1956) argued that managers unwilling to change payout ratio without any important change on the firm`s future performance. Won and Kim (1992) report that managers are more likely to be concerned about the internal factors such as net income, divisible surplus, predicted future performance, and the shareholders` preference for dividend policy. More importantly, several studies suggest that the foreign investors have a significant effect on the Korean market. Park (2004) reports that foreign investors` participation in firms generally pushes up the dividend payments while pulling down investments made in facilities no matter which industry a company is in. Sul and Kim (2006) show that those companies whose majority shareholders are foreign investors tend to pay higher dividends than others whose majority shareholders are domestic investors. In contrast to negative effect of foreign investor, there are empirical studies claiming positive impact of foreign investor in Korean market. Ahn, Shin, and Chang (2005) suggest that foreign investors prefer firms with lower information asymmetry. The study also shows that foreign investors can effectively monitor the management of firm in lessening information asymmetry. Similarly, Park and Lee (2006) suggest that foreign investors` participation in investment of domestic firms can help them make more efficient management decision by improving their corporate governance. Thus, Park and Lee claim that it is problematic to generalize the negative role of foreign investors in the Korean market. Based on this argument, we predict that if foreign investors play an effective monitoring role in a dividend policy, dividend change for firms with higher level of foreign investors is a good indicator in predicting future earnings than for firms with lower level of foreign investors. However, if foreign investors play a negative role in dividend decision process, predictability of dividend decreases. We test this prediction by using the modified model with several control variables that can affect earnings changes. Using 6,720 observations from 1993 to 2007, we find that the dividend change predicts future earnings for next one year relative to the dividend change year. Specifically, the coefficient on RDIV is 0.045 (t=6.85) and this indicates the dividend increases is a good indicator in predicting future earnings. When it comes to model specification, adjusted R2 of modified model is greater than that of the basic model, which means that the modified model is well specified in explaining earnings changes. The result of the effect of foreign investors on predictability of dividend is not significant. This finding implies that managers, on average, decide to pay dividend as a response to demand from foreign investors.

Effect of Total Hip Arthroplasty on Ipsilateral Lower Limb Alignment and Knee Joint Space Width: Minimum 5-Year Follow-up

Choi Yun Seong,Park Jung-Wee,Kim Tae Woo,Kang Kee Soo,Lee Young-Kyun,Koo Kyung-Hoi,Chang Chong Bum 대한의학회 2023 Journal of Korean medical science Vol.38 No.20

Background: This study aimed to 1) assess the effect of total hip arthroplasty (THA) on coronal limb alignment, namely, the hip–knee–ankle angle (HKA), 2) identify factors that determine changes in the HKA, and 3) determine whether alignment changes influence the knee joint space width. Methods: We retrospectively evaluated 266 limbs of patients who underwent THA. Three types of prostheses with neck shaft angles (NSAs) of 132°, 135°, and 138° were used. Several radiographic parameters were measured in the preoperative and final radiographs (at least 5 years after THA). A paired t-test was used to confirm the effect of THA on HKA change. Multiple regression analysis was performed to identify radiographic parameters related to HKA changes following THA and changes in knee joint space width. Subgroup analyses were performed to reveal the effect of NSA change on the HKA change, and the proportion of total knee arthroplasty usage and changes in radiographic parameters between maintained joint space and narrowed joint space groups were compared. Results: The preoperative mean HKA was 1.4° varus and increased to 2.7° varus after THA. This change was related to changes in the NSA, lateral distal femoral angle, and femoral bowing angle. In particular, in the group with a decrease in NSA of > 5°, the preoperative mean HKA was largely changed from 1.4° varus to 4.6° varus after THA. The prostheses with NSA of 132° and 135° also led to greater varus HKA changes than those with an NSA of 138°. Narrowing of the medial knee joint space was related to changes in the varus direction of the HKA, decrease in NSA, increase in femoral offset. Conclusion: A large reduction in NSA can lead to considerable varus limb alignment after THA, which can have adverse effects on the medial compartment of the ipsilateral knee.

Fault Diagnosis of Roll Shape Under the Speed Variation in Hot Rolling Mill

Chang Woo Lee,Hyun Kyoo Kang,Kee Hyun Shin 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.9

The metal processing system usually consists of various components such like motors, work rolls, backup rolls, idle rolls, sensors, etc. Even a simple fault in a single component in the system may cause a serious damage on the final product. It is therefore necessary to diagnose the faults of the components to detect and prevent system failure. Especially, the defects in a work roll are critical to the quality of strip. It is especially difficult to detect faults of a roll by using the existing frequency analysis method if the speed of the roll is changing. In this study, a new diagnosis method for roll eccentricity under the roll speed changes was developed. The new method was induced from analyzing the rolling mechanism by using rolling force models, radius -speed relationship, and measured rolling force, etc. Simulation results by using the field data show that the proposed method is very useful.

Characterization of changes in global gene expression in the brain of neuron-specific enolase/human Tau23 transgenic mice in response to overexpression of Tau protein.

Woo, Jong-Min,Park, So Jung,Kang, Ho Il,Kim, Byoung Guk,Shim, Sun Bo,Jee, Seung Wan,Lee, Su Hae,Sin, Ji Soon,Bae, Chang Joon,Jang, Mee Kyung,Cho, Chunghee,Hwang, Dae Youn,Kim, Chuel Kyu D.A. Spandidos 2010 INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE Vol.25 No.5

<P>Tau is a neuronal phosphoprotein responsible for the formation of the neurofibrillary tangles in Alzheimer's disease. To characterize the changes in global gene expression in the brain of transgenic mice that overexpress human Tau23 protein in response to the increase of Tau23 phosphorylation, total RNA extracted from the hippocampus of 12-month-old transgenic and wild-type mice was converted to cDNA, labeled with biotin and hybridized to oligonucleotide microarrays. The microarray results were confirmed by real-time RT-PCR and Western blotting method. It was determined that 43 genes were up-regulated and 8 genes were down-regulated by Tau23 in transgenic mice compared to controls, based on the arbitrary difference in the 2-fold change. Among the up-regulated transcripts, those encoding for transporter and oxidoreductase were dramatically over-represented, followed by those related to regulatory molecule, cytoskeletal protein, signaling molecule, and extracellular matrix protein. Genes encoding for transcription factor, regulatory molecule, miscellaneous function, and chaperone were significantly reduced in the down-regulated group. The major genes in the up-regulated categories included Ecrg4, Folr1, Defb11, Aqp1 and Soctdc1. The major genes in the down-regulated categories were Ncor1, Gpm6a, and Hspd1. These results indicate that the microarray analysis identifies several gene functional groups and individual genes that respond to a sustained increase in Tau23 phosphorylation levels in the brain of transgenic mice. In addition, the results suggest the microarray test is a useful tool for increased understanding of the role of Tau23 protein in regulating neurodegenerative disorders.</P>

Fault Diagnosis of Roll Shape Under the Speed Variation in Hot Rolling Mill

Lee, Chang-Woo,Kang, Hyun-Kyoo,Shin, Kee-Hyun The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.9

The metal processing system usually consists of various components such like motors, work rolls, backup rolls, idle rolls, sensors, etc. Even a simple fault in a single component in the system may cause a serious damage on the final product. It is therefore necessary to diagnose the faults of the components to detect and prevent system failure. Especially, the defects in a work roll are critical to the quality of strip. It is especially difficult to detect faults of a roll by using the existing frequency analysis method if the speed of the roll is changing. In this study, a new diagnosis method for roll eccentricity under the roll speed changes was developed. The new method was induced from analyzing the rolling mechanism by using rolling force models, radius-speed relationship, and measured rolling force, etc. Simulation results by using the field data show that the proposed method is very useful.

『난경회주전정』중 장부생리에 대한 연구

제강우 ( Kang Woo Je ),윤창열 ( Chang Yeu Yoon ) 대전대학교 한의학연구소 2006 한의학연구소 논문집 Vol.15 No.2

Clinical Experiences and Usefulness of Cervical Posterior Stabilization with Polyaxial Screw-Rod System

Hwang, In-Chang,Kang, Dong-Ho,Han, Jong-Woo,Park, In-Sung,Lee, Chul-Hee,Park, Sun-Young The Korean Neurosurgical Society 2007 Journal of Korean neurosurgical society Vol.42 No.4

Objective : The objective of this study is to investigate the safety, surgical efficacy, and advantages of a polyaxial screw-rod system for posterior occipitocervicothoracic arthrodesis. Methods : Charts and radiographs of 32 patients who underwent posterior cervical fixation between October 2004 and February 2006 were retrospectively reviewed. Posterior cervical polyaxial screw-rod fixation was applied on the cervical spine and/or upper thoracic spine. The surgical indication was fracture or dislocation in 18, C1-2 ligamentous injury with trauma in 5, atlantoaxial instability by rheumatoid arthritis (RA) or diffuse idiopathic skeletal hyperostosis (DISH) in 4, cervical spondylosis with myelopathy in 4, and spinal metastatic tumor in 1. The patients were followed up and evaluated based on their clinical status and radiographs at 1, 3, 6 months and 1 year after surgery. Results : A total of 189 screws were implanted in 32 patients. Fixation was carried out over an average of 3.3 spinal segment (range, 2 to 7). The mean follow-up interval was 20.2 months. This system allowed for screw placement in the occiput, C1 lateral mass, C2 pars, C3-7 lateral masses, as well as the lower cervical and upper thoracic pedicles. Satisfactory bony fusion and reduction were achieved and confirmed in postoperative flexion-extension lateral radiographs and computed tomography (CT) scans in all cases. Revision surgery was required in two cases due to deep wound infection. One case needed a skin graft due to necrotic change. There was one case of kyphotic change due to adjacent segmental degeneration. There were no other complications, such as cord or vertebral artery injury, cerebrospinal fluid leak, screw malposition or back-out, or implant failure, and there were no cases of postoperative radiculopathy due to foraminal stenosis. Conclusion : Posterior cervical stabilization with a polyaxial screw-rod system is a safe and reliable technique that appears to offer several advantages over existing methods. Further biomechanical testings and clinical experiences are needed in order to determine the true benefits of this procedure.