• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.16
• /
• pp.6819-6822
• /
• 2014

Background: The aim of this study was to evaluate the accuracy of a new scoring system in Korean patients with hematuria at high risk of bladder cancer. Materials and Methods: A total of 319 consecutive patients presenting with painless hematuria without a history of bladder cancer were analyzed, from the period of August 2012 to February 2014. All patients underwent clinical examination, and 22 patients with incomplete data were excluded from the final validation data set. The scoring system included four clinical parameters: age (${\geq}50$ = 2 vs. <50 =1), gender (male = 2 vs. female = 1), history of smoking (smoker/ex-smoker = 4 vs. non-smoker = 2) and nature of the hematuria (gross = 6 vs. microscopic = 2). Results: The area under the receiver-operating characteristic curve (95% confidence interval) of the scoring system was 0.718 (0.655-0.777). The calibration plot demonstrated a slight underestimation of bladder cancer probability, but the model had reasonable calibration. Decision curve analysis revealed that the use of model was associated with net benefit gains over the treat-all strategy. The scoring system performed well across a wide range of threshold probabilities (15%-45%). Conclusions: The scoring system developed is a highly accurate predictive tool for patients with hematuria. Although further improvements are needed, utilization of this system may assist primary care physicians and other healthcare practitioners in determining a patient's risk of bladder cancer.

• Journal of Korea Multimedia Society
• /
• v.21 no.8
• /
• pp.837-848
• /
• 2018

Monitoring technology of machining has a long history since unmanned machining was introduced. Despite the long history, many researchers have presented new approaches continuously in this area. Sound based machine fault diagnosis is the process consisting of detecting automatically the damages that affect the machines by analyzing the sounds they produce during their operating time. The collected sound is corrupted by the surrounding work environment. Therefore, the most important part of the diagnosis is to find hidden elements inside the data that can represent the error pattern. This paper presents a feature extraction methodology that combines various digital signal processing and pattern recognition methods for the analysis of the sounds produced by tools. The magnitude spectrum of the sound is extracted using the Fourier analysis and the band-pass filter is applied to further characterize the data. Statistical functions are also used as input to the nonlinear classifier for the final response. The results prove that the proposed feature extraction method accurately captures the hidden patterns of the sound generated by the tool, unlike the conventional features. Therefore, it is shown that the proposed method can be applied to a sound based automatic diagnosis system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.05a
• /
• pp.18-21
• /
• 2009

The life of components under high thermal load is typically shorter than other components. The turbopump turbine of liquid rocket is operated under these environments like high temperature and high centrifugal dorce due to high rotating velocity during operating time. These conditions may often cause low-cycle fatigue problem in the turbopump turbine. First of all, to analyze heat stress, ABAQUS/CAE is used and Coffin-manson's equation is used to consider elasticity and plasticity strain. S.W.T's method is used to consider the mean stress effect, using strain history, low-cycle fatigue analysis is done for turbopump turbine which may have FCL(fracture critical location). In this paper, strain life method is applied to analyze low-cycle fatigue.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.10a
• /
• pp.325-330
• /
• 2011

RCP(Reactor coolant pump) must be designed to preserve it's functions on normal or abnormal environments and seismic event same as operating basis earthquake(OBE) and safe shutdown earthquake(SSE). Generally, there are static and dynamic analytical method which can be applied by a floor response spectrum or time history analysis for the seismic qualification. Initially, It was accomplished a detailed structural FE-model for finite element analysis on the bases of 3-dimensional solid model which was made by the RCP drawing. As the result of dynamic characteristic using the detailed FE-model, it's shown about 12Hz natural frequency of 1st bending mode shape and maximum displacement has 11mm with the structural bending by single-point response spectrum(SPRS) method at all elevation. But maximum displacement has 7.6mm by multi-point response spectrum(MPRS) method which was applied to the three floor response spectrum at each elevation. Therefore, On a large heighten structures as RCP, The application by SPRS method causes to be more conservative results. Finally, A simpled equivalent beam model which was developed by use of iteration of detailed FE-model is shown the result more similar with those of natural frequencies and SPRS analysis. And maximum equivalent stress and displacement of the simpled beam has verified with 180MPa and 7.1mm each at 15sec as results by SSE time history method.

• Journal of Preventive Medicine and Public Health
• /
• v.53 no.5
• /
• pp.313-322
• /
• 2020

Objectives: This study was conducted to determine the incidence and risk factors of myocardial infarction (MI) and stroke in farmers compared to the general population and to establish 5-year prediction models. Methods: The farmer cohort and the control cohort were generated using the customized database of the National Health Insurance Service of Korea database and the National Sample Cohort, respectively. The participants were followed from the day of the index general health examination until the events of MI, stroke, or death (up to 5 years). Results: In total, 734 744 participants from the farmer cohort and 238 311 from the control cohort aged between 40 and 70 were included. The age-adjusted incidence of MI was 0.766 and 0.585 per 1000 person-years in the farmer and control cohorts, respectively. That of stroke was 0.559 and 0.321 per 1000 person-years in both cohorts, respectively. In farmers, the risk factors for MI included male sex, age, personal history of hypertension, diabetes, current smoking, creatinine, metabolic syndrome components (blood pressure, triglycerides, and high-density lipoprotein cholesterol). Those for stroke included male sex, age, personal history of hypertension, diabetes, current smoking, high γ-glutamyl transferase, and metabolic syndrome components (blood pressure, triglycerides, and high-density lipoprotein cholesterol). The prediction model showed an area under the receiver operating characteristic curve of 0.735 and 0.760 for MI and stroke, respectively, in the farmer cohort. Conclusions: Farmers had a higher age-adjusted incidence of MI and stroke. They also showed distinct patterns in cardiovascular risk factors compared to the general population.

• Journal of Korea Soil Environment Society
• /
• v.4 no.2
• /
• pp.163-174
• /
• 1999

This paper presents a case history of remedial action adopted for contaminated groundwater in a landfill. The objectives of the projects are : (1) to effectively confine contaminated groundwater with an economically reasonable means, (2) to prevent further contamination of soil by collecting and treat the contaminant. and (3) to assure the environmental safety of the landfill during its operating period. Reported are the process from site investigation, through design and construction of an appropriate remedial action, to the monitoring of the selected confinement system. In view of the results of site investigation, deep soil mixing cutoff wall using the DMW(deep soil mixing cutoff wall) method and specially produced HEC soil stabilizer were used for the construction of deep soil mixing cutoff wall. For rock foundation with sever fractures, chemical grout curtain with urethane was installed. The monitoring results to date indicate that the selected vertical barrier performed satisfactorily.

• Journal of Chest Surgery
• /
• v.5 no.1
• /
• pp.19-24
• /
• 1972

The recent development of cardiovascular surgery as well as aortoarteriogaphy has been established excellent operative result with great aid of limb-salvage. However, less consideration or less experience still exists on the regard of vascular accident and vascular disease, as well as vascular surgery in Korea. During the last 13 years, we experienced only two cases of aorto-iliac occlusion,acute and chronic, regardless of having had more than 300 cases of mitral valvotomy and gradual increasing tendency of arteriosclerosis and hypertension in Korea. Therefore it is noteworthy to report the cases in order to promote the consideration for vascular surgery. Case 1; 52 year old female who had 20 years history of mitral stenosis with uricular fibrillation and received medical treatment for recent 1 year in the medical department. 10 days before admission, acute saddle emboli developed and 15 days after the onset, embolectomy through both common femoral arteries on the groin and abdominal approach was made. The progression of emboll to the right popliteal bifurcation was found by arteriography on operating table and retrograde flushing with heparin solution by the polyethylene catheter inserted through posterior tibial artery. The operation was successful, but 9 hours after operation sudden death occurred. Considering this case, first, mitral valvotomy already before might prevent peripheral embolizatlon, secondarily, the more early detection and surgery might also prevent the progression of emboli. Thirdly, although preoperative or postoperatlve heparinization is controversial for mitraI stenosis, heparinization might prevent additional emboli to vital organs in this case Cases 2; 66 year old female who had 4 years history of left hip and calf intermittent claudication and has had rest pain, inability to walk and ischemic necrosis on the the left leg since last 3 months prior to admission to the orthopedic department under the suspicion of herniated disc. Absence of pulsation on the groin and aortography evidenced aortoillac occlusion predominantly on the left side. Thromboendarterectomy was made and the operative result was successful with absence of claudication, healing of ulcer and aortographic patency of occlusive site. This chronic occlusion is considered to result from arteriosclerosis in origin with the evidence of moderate hypertension, x-ray evidence of calcified plaque on the aortic knob and operative finding of palpable plaques.

• Journal of Korean Neurosurgical Society
• /
• v.64 no.2
• /
• pp.189-197
• /
• 2021

Objective : This study aims to investigate the relationship between aneurysm wall enhancement and clinical rupture risks based on the magnetic resonance vessel wall imaging (MR-VWI) quantitative methods. Methods : One hundred and eight patients with 127 unruptured aneurysms were prospectively enrolled from Feburary 2016 to October 2017. Aneurysms were divided into high risk (≥10) and intermediate-low risk group (<10) according to the PHASES (Population, Hypertension, Age, Size of aneurysm, Earlier SAH history from another aneurysm, Site of aneurysm) scores. Clinical risk factors, aneurysm morphology, and wall enhancement index (WEI) calculated using 3D MR-VWI were analyzed and compared. Results : In comparison of high-risk and intermediated-low risk groups, univariate analysis showed that neck width (4.5±3.3 mm vs. 3.4±1.7 mm, p=0.002), the presence of wall enhancement (100.0% vs. 62.9%, p<0.001), and WEI (1.6±0.6 vs. 0.8±0.8, p<0.001) were significantly associated with high rupture risk. Multivariate regression analysis revealed that WEI was the most important factor in predicting high rupture risk (odds ratio, 2.6; 95% confidence interval, 1.4-4.9; p=0.002). The receiver operating characteristic (ROC) curve analysis can efficiently differentiate higher risk aneurysms (area under the curve, 0.780; p<0.001) which have a reliable WEI cutoff value (1.04; sensitivity, 0.833; specificity, 0.67) predictive of high rupture risk. Conclusion : Aneurysms with higher rupture risk based on PHASES score demonstrate increased neck width, wall enhancement, and the enhancement intensity. Higher WEI in unruptured aneurysms has a predictive value for increased rupture risk.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.8
• /
• pp.2906-2916
• /
• 2010

Purpose : The purpose of this study was to identify musculoskeletal symptom and pain related working posture with operation-room workers. Methods: The subjects of this study were 73 people who were working from hospital operating-room. A questionnaire consisting of general characteristics, pain symptoms, and pain frequency was given. Objective working posture analysis was done by using REBA after recording moving images in hospital operating-rooms. Results: The result were as follows. The risk level of musculoskeletal symptom related working posture was high, and the management level was at the least 2; 'some management was required for musculoskeletal symptom'. The frequency of pain was 3~4 times/week and the severe pain were experienced from legs, neck, and shoulder. The result of relation of general characteristics and pain were significant variable with sex, age, marital status, weight, past working history, average working time(hr/day), working style, and working department. Conclusion: These results contribute to a better understanding of operation-room workers have high possibility of musculoskeletal disease and are severe musculoskeltal pain related working posture.

• Journal of the Korean Society for Railway
• /
• v.12 no.1
• /
• pp.16-24
• /
• 2009

In this study, fatigue crack growth rate of a cracked railway bogie frame under variable amplitude loading is predicted by applying linear elastic fracture mechanics. For this purpose, we find the critical points by reference surveying on cracked railway bogie frames. And we make an effective load history by synthesizing the dynamic load measured from the critical points of railway bogie frame during commercial line operation and the static load calculated from structural analysis. Crack growth analyses are performed at the 3 critical points under the commercial operation loading condition by assuming an initial crack size as 40 mm. and the results are compared with the experimental results from Japanese railway bogie frame crack growth case. From the analysis results, we find that around 500,000 km operating distance is necessary to bring crack growth from the initial crack to unstable crack. And it takes around 3.8 normal operating years. We conclude that it is enough time to detect the crack between normal maintenance period.