Fifteen Years After the Gozan-Dong Glass Fiber Outbreak, Incheon in 1995

Objectives: In 1995, an outbreak survey in Gozan-dong concluded that an association between fiberglass exposure in drinking water and cancer outbreak cannot be established. This study follows the subjects from a study in 1995 using a data linkage method to examine whether an association existed. The authors will address the potential benefits and methodological issues following outbreak surveys using data linkage, particularly when informed consent is absent. Methods: This is a follow-up study of 697 (30 exposed) individuals out of the original 888 (31 exposed) participants (78.5%) from 1995 to 2007 assessing the cancer outcomes and deaths of these individuals. The National Cancer Registry (KNCR) and death certificate data were linked using the ID numbers of the participants. The standardized incidence ratio (SIR) and standardized mortality ratio (SMR) from cancers were calculated by the KNCR. Results: The SIR values for all cancer or gastrointestinal cancer (GI) occurrences were the lowest in the exposed group (SIR, 0.73; 95% CI, 0.10 to 5.21; 0.00 for GI), while the two control groups (control 1: external, control 2: internal) showed slight increases in their SIR values (SIR, 1.18 and 1.27 for all cancers; 1.62 and 1.46 for GI). All lacked statistical significance. All-cause mortality levels for the three groups showed the same pattern (SMR 0.37, 1.29, and 1.11). Conclusions: This study did not refute a finding of non-association with a 13-year follow-up. Considering that many outbreak surveys are associated with a small sample size and a cross-sectional design, follow-up studies that utilize data linkage should become standard procedure.OAIID:oai:osos.snu.ac.kr:snu2011-01/102/0000040632/15SEQ:15PERF_CD:SNU2011-01EVAL_ITEM_CD:102USER_ID:0000040632ADJUST_YN:YEMP_ID:A077602DEPT_CD:902CITE_RATE:0FILENAME:fifteen years after the gozan-dong glass fiber outbreak, incheon in 1995..pdfDEPT_NM:보건학과CONFIRM:

Redirected Walking in Infinite Virtual Indoor Environment Using Change-blindness

We present a change-blindness based redirected walking algorithm that allows a user to explore on foot a virtual indoor environment consisting of an infinite number of rooms while at the same time ensuring collision-free walking for the user in real space. This method uses change blindness to scale and translate the room without the user's awareness by moving the wall while the user is not looking. Consequently, the virtual room containing the current user always exists in the valid real space. We measured the detection threshold for whether the user recognizes the movement of the wall outside the field of view. Then, we used the measured detection threshold to determine the amount of changing the dimension of the room by moving that wall. We conducted a live-user experiment to navigate the same virtual environment using the proposed method and other existing methods. As a result, users reported higher usability, presence, and immersion when using the proposed method while showing reduced motion sickness compared to other methods. Hence, our approach can be used to implement applications to allow users to explore an infinitely large virtual indoor environment such as virtual museum and virtual model house while simultaneously walking in a small real space, giving users a more realistic experience.Comment: https://www.youtube.com/watch?v=s-ZKavhXxd

Development of multistage 10-m shuttle run test for VO2max estimation in healthy adults

Background and objective: The disadvantage of the traditional 20-m multistage shuttle run test (MST) is that it requires a long space for measurements and does not include various age groups to develop the test. Therefore, we developed a new MST to improve the spatial limitation by reducing the measurement to a 10-m distance and to resolve the bias via uniform distributions of gender and age. Material and methods: Study subjects included 120 healthy adults (60 males and 60 females) aged 20 to 50 years. All subjects performed a graded maximal exercise test (GXT) and a 10-m MST at five-day intervals. We developed a regression model using 70% of the subject’s data and performed a cross-validation test using 30% of the data. Results: The male regression model’s coefficient of determination (R2) was 58.8%, and the standard error of estimation (SEE) was 4.17 mL/kg/min. The female regression model’s R2 was 69.2%, and the SEE was 3.39 mL/kg/min. The 10-m MST showed a high correlation with GXT on the VO2max (males: 0.816; females: 0.821). In the cross-validation test for the developed regression models, the male’s SEE was 4.38 mL/kg/min, and the female’s SEE was 4.56 mL/kg/min. Conclusion: Thus, the 10-m MST is an accurate and valid method for estimating the VO2max. Therefore, the 10-m MST developed by us can be used when the existing 20-m MST cannot be used due to spatial limitations and can be applied to both men and women in their 20s and 50s

Collision-geometry-based optimal guidance for high-speed target

This paper proposes a new unified form of guidance law based on the collision geometry that can be applied to both head-on (HO) or head-pursuit (HP) engagements for intercepting a target faster than an interceptor. To this end, two possible collision courses for a high-speed target and corresponding nonlinear heading errors are first investigated. The proposed guidance is then determined in a way to specify the desired heading error dynamics that ensures an optimal decreasing pattern. The characteristics of the proposed method are also investigated compared to existing methods. The favorable features are that the engagement geometries between HO or HP can be flexibly selected, and the optimality of the guidance command can be addressed. Moreover, since the proposed guidance law is directly derived from nonlinear collision geometry, the working mechanism is clearly explained, and the nonlinear nature is preserved. Finally, numerical simulations are performed to support our findings

Lightweight Monocular Depth Estimation via Token-Sharing Transformer

Depth estimation is an important task in various robotics systems and applications. In mobile robotics systems, monocular depth estimation is desirable since a single RGB camera can be deployable at a low cost and compact size. Due to its significant and growing needs, many lightweight monocular depth estimation networks have been proposed for mobile robotics systems. While most lightweight monocular depth estimation methods have been developed using convolution neural networks, the Transformer has been gradually utilized in monocular depth estimation recently. However, massive parameters and large computational costs in the Transformer disturb the deployment to embedded devices. In this paper, we present a Token-Sharing Transformer (TST), an architecture using the Transformer for monocular depth estimation, optimized especially in embedded devices. The proposed TST utilizes global token sharing, which enables the model to obtain an accurate depth prediction with high throughput in embedded devices. Experimental results show that TST outperforms the existing lightweight monocular depth estimation methods. On the NYU Depth v2 dataset, TST can deliver depth maps up to 63.4 FPS in NVIDIA Jetson nano and 142.6 FPS in NVIDIA Jetson TX2, with lower errors than the existing methods. Furthermore, TST achieves real-time depth estimation of high-resolution images on Jetson TX2 with competitive results.Comment: ICRA 202

Cyclooxygenase-2 and p53 Expression as Prognostic Indicators in Conventional Renal Cell Carcinoma

The aim of this study was to investigate the relationship of cyclooxygenase (COX)-2 and p53 expression with prognosis in patients with conventional renal cell carcinoma (RCC). Formalin-fixed, paraffin-embedded tissue sections of conventional RCC from 92 patients, who had undergone radical nephrectomy, were examined for COX-2 and p53 expression by immunohistochemistry and compared with clinicopathological variables. The COX-2 expression significantly correlated only with tumor size (p=0.049), whereas the p53 expression profoundly correlated with the TNM stage (p=0.024), M stage (p=0.001), and metastasis (synchronous or metachronous; p=0.004). The COX-2 overexpression did not significantly associate with p53 positivity (p=0.821). The survival rate of patients correlated with the p53 expression (p<0.0001) but not with the COX-2 expression (p=0.7506). Multivariate analyses indicated that tumor size, M stage, and p53 expression were independent prognostic factors for cancer-specific survival. The COX-2 expression was not an independent factor. These results show that the increased expression of p53 was associated with metastasis and a worse prognosis in conventional RCC, which suggests that p53 might have played an important role in the progression of conventional RCC. The increased expression of COX-2 was associated only with tumor size, but may not be an important prognostic factor in conventional RCC. No association was observed between COX-2 overexpression and p53 positivity in conventional RCC