• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.20-25
• /
• 1994

절삭공정의 자동화의 무인화를 달성하기 위해서는 경험을 가진 작업자의 역활이 컴퓨터에 의한 자동적인 감시 및 제어시스템으로 대체되어야 한다. 특히 공작기계에서 발생할 수 있는 자체의 고장이나 절삭과정중에 발생하는 이상상태를 실시간으로 검출하여 원인을 자동적으로 진달 할 수 있어야 한다. 절삭가공 공작기계의 이상상태 감시 및 진단의 현황을 살펴보면 주로 공구상태의 감시와 채터 감시가 연구의 대상 이 되고 있다. 공구상태의 감시는 공구의 마모와 파단을 검출하고 있다. 이 중에서 공구의 파단은 발생 즉시 실시간으로 감시되어야 한다. 밀링작업에서는 1회전 이내의 공구회전에 파단을 검출하고 기계를 정지시켜야 한다. 최근의 절삭가공에서는 절삭공구로 강력절삭을 위해 고경도 재료를 사용함에 따라 공구의 파단이 빈번하게 발생하고 있다. 정면밀링과 같은 단속절상에서는 절삭날이 큰 충격을 받으므로 더욱 파단에 대한 감시가 필요하다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2011.11a
• /
• pp.1055-1058
• /
• 2011

본 논문은 IT분야의 다양한 융합 기술 분야 중에서 언제 어디서나 사용자의 건강상태를 실시간으로 확인 할 수 있는 u-Health 시스템(Ubiquitous Health System)을 구현하였다. 현재 서비스되고 있는 u-Health 시스템은 초기 단계로 사용자의 상태를 확인하는 센서 기기에 의존하여 센서로부터 측정된 데이터를 가족 및 의료기관 등이 직접 분석하여 대처 하는 방법을 사용하고 있다. 그러나 기존에 개발된 u-Health 시스템은 센서 기기에 대한 오동작과 응급상황 발생 시 정확하고 신속한 대처를 할 수 없다는 단점을 가지고 있다. 따라서 본 논문에서는 u-Health 시스템의 단점을 보완하고자 기존 u-Health 시스템에 질환판별 알고리즘을 적용하여 사용자의 상태를 진단하고 이상 징후나 응급상황을 판단 할 수 있도록 하여 신뢰성을 높인다. 또한 질환판별 결과가 응급상황으로 판정될 시 가족 및 의료기관에 실시간으로 문자 메시지를 전송하여 알림 역할을 하고, 스마트폰과 웹페이지를 이용하여 실시간으로 사용자의 상태를 확인할 수 있도록 하여 신속성을 높이는데 목적이 있다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.9
• /
• pp.3330-3335
• /
• 2010

Due to the acceleration of medical information age, the semantic interoperability of clinical information is rising up as a major issue. The laboratory results are known as the best significant area among clinical information to be required for exchanging and sharing. The aim of this research is to develop the clinical contents model for exchange laboratory results. This research was conducted from March 2008 to September 2008. Firstly, the method is to get the attributes and codes from LOINC which is one of the standard medical terminology system related to laboratory and the Reference Information Model(RIM) of Health Level 7(HL7). Secondly, the attributes from each work process around orders and reports of laboratory was analyzed. We evaluated the attributes whether they could be represented into the attributes contained in HL7's RIM. Thirdly, the prototype for hemoglobin case using the structure of clinical contents model and defined attribute. Fourthly, the face validity was done by one laboratory physician with four clinicians. The assessment contents were for the suitability involved in representation and exchange with proposed model. The results shows that the model corresponds with the aim of the research. Eventually the proposed model for the exchange of laboratory results could contributes to information interchange according to laboratory area for the future.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.7
• /
• pp.1573-1582
• /
• 2011

Risk of lung cancer among lung-related diseases has gradually increased during last decades. The chest digital radiography is the primary diagnosis method for lung cancer. Diagnosing lung cancer using this method requires doctors of ripe experience. Despite their experience there are often wrong diagnoses, which decrease early diagnosis and survival rates of patients. The aim of this study was intended to establish the base on the Computer Aided Diagnosis (CAD) by analyzing Image Recognition Algorithm using Principle component Analysis (PCA) and diagnosing patient's chest X-ray image. The database obtained through this approach enables a doctor to significantly reduce misdiagnosis during the early diagnosis stage, if he or she utilizes it as the preliminary reading step. Case studies were carried out using normal organ, and organs suffering from bronchogenic carcinoma and granuloma. A normal image and unique disease images were extracted after PCA analysis, and their cross-recognition efficiency were compared each other. The result revealed that the recognition rate was much high between normal and disease images, but relatively low between two disease images. In order to increase the recognition efficiency among chest diseases the related algorithms have to be developed continuously in the future study, and such effort will establish the resolute base for CAD.

• The Korean Journal of Nuclear Medicine
• /
• v.31 no.1
• /
• pp.30-35
• /
• 1997

It has been shown that both rest and stress myocardial perfusion imagings with technetium agents can be performed on the same day using two different doses injected within few hours. The purpose of this study was to compare the two protocols (stress-rest and rest-stress) in detecting coronary artery diseases. One hundred and sixty patients (101 males, 59 females, mean age $57{\pm}9$ years) and 120 patients (79 males, 41 females, mean age $59{\pm}10$ years) underwent stress-rest myocardial perfusion SPECT and rest-stress myocardial perfusion SPECT, respectively. All of them underwent both myocardial perfusion SPECT and coronary angiography within 1 month. A coronary stenosis was considered significant when it compromised the luminal diameter by ${\geq} 50%$. The chi square test was used to compare differences in sensitivity, specificity and accuracy between the two groups. The overall sensitivity, specificity and accuracy of stress-rest protocol were 99%, 35% and 68%, respectively. Those of rest-stress protocol were 96%, 47% and 78%, respectively. There was no difference between the two protocols in identifying individual diseased coronary artery branches. Therefore, one day stress-rest and rest-stress myocardial SPECT using $^{99m}Tc$ agents were comparable and were very sensitive tests in detecting coronary artery diseases.

• Pediatric Infection and Vaccine
• /
• v.30 no.2
• /
• pp.97-103
• /
• 2023

Kawasaki disease (KD) is an acute, systemic inflammatory disorder that often targets coronary arteries. Being the common cause of acquired heart disease in children, timely diagnosis and intravenous immunoglobulin treatment are crucial. However, it is challenging for physicians to diagnose KD if it presents with atypical manifestations. We report the case of a 5-year-old boy who initially presented with appendicitis; after an appendectomy, he had a prolonged fever. He was finally diagnosed with atypical KD and successfully recovered after intravenous immunoglobulin treatment. Through a literature review, we found 21 cases of appendicitis associated with KD. In most cases, the patients were male with a mean age of 5.3 years. Most had higher proportions of incomplete KD and coronary artery complications than expected for typical KD. In conclusion, appendicitis could be a rare complication of KD; therefore, multidisciplinary cooperation and early recognition of atypical KD are essential for timely diagnosis.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.5
• /
• pp.49-55
• /
• 2017

In the seventies, a number of researchers carried out experiments on pullout tests with prototype equipment, and the pullout test was certified as a reliable nondestructive testing(NDT) method for determining the strength of concrete. To estimate the strength of high-strength concrete, we propose a simplified pullout test that uses as a break-off bolt a standard 10mm bolt with a groove on the shaft, an insert nut, and a pullout instrument that includes a hydraulic oil pump without a load cell. To verify the advantages of the simplified pullout test(low cost, simplicity, and convenience), four wall specimens were tested with two levels of concrete strength, 30 MPa and 50 MPa, using a simplified pullout tester with a load cell. The pullout load and concrete compressive strength were measured every day until day 7, day 14, day 21 and day 28. It was found that the pullout load was very similar to the compressive strength. Therefore, we have verified that a simplified pullout test can be used to evaluate the in-place strength of high-strength concrete in structures. The prediction equation of the groove diameter of the break-off bolt(y) with the concrete strength(x) was derived as y=0.05x+3.79, with a coefficient of determination of 0.88 found through regression analysis.

• Journal of Biomedical Engineering Research
• /
• v.20 no.2
• /
• pp.173-182
• /
• 1999

Contrast-enhanced CT has an important role in assessing liver lesions, the optimal protocol to get most effective result is not clear. The mein goal when deciding injention protocol is to optimize lesion detectability with rapid scanning when lesion to liver contrast is maximum. For this purpose, we developed a physiological model of the contrast medium enhancement based on the compartment modeling and pharmacokinetics. Blood supply to liver is achieved in two paths. This dual supply characteristic distinguishes the CT enhancement of liver from that of the other organs. The first path is by hepatic artery and to second, by portal vein. However, it is assumed that only gepatic artery can supply blood to hepatocellular carcinoma(HCC) compartment, thus, the difference of contrast enhancement is resulted between normal liver tissue and hepatic tumor. By solving differential equations for each compartment simultaneously using the computer program Matlab, CT contrast-enhancement curves were simulated. The simulated enhancement curves for aortic, hepatic, portal vein, and HCC compartments were compared with the mean enhancement curves from 24 patients exposed to the same protocols as the simulation. These enhancement curves showed a good agreement. Furthermore, we simulated lesion-to-liver curves for various injection protocols, and the effects were analyzed. The variables to be considered in the injection protocol were injection rate, dose, and concentration of contrast material. These data may help to optimize scanning protocols for better diagnosis.

• 대한공업교육학회지
• /
• v.41 no.2
• /
• pp.151-171
• /
• 2016

The purpose of this study is to verify the effect of Interdisciplinary course for improving the competency of collegiate Interpersonal & Cooperative Skills, Resources-Information-Technology Processing & Application and Communication. The course proved to be effective based on the result for examination of difference between the experimental group of 43 students who took the interdisciplinary course and the control group of 44 students who did not take that course of the second semester of H university in 2015. The study applied the method of Paired-sample T-Test to investigate the difference of Interpersonal & Cooperative Skills, Resources-Information-Technology Processing & Application and Communication and their sub-skills between the two participant groups. As a result, Interdisciplinary course had an effect on improvement of Interpersonal & Cooperative Skills and it's sub skills; however, it had no effect on improvement of Resources-Information-Technology Processing & Application and Communication competency and their sub-skills. The results provide theoretical and practical implications for the interdisciplinary course and core competence of college students. They suggest that interdisciplinary course design should be more careful to improve students' competency on Resources-Information-Technology Processing & Application and Communication competency than before.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.6
• /
• pp.172-181
• /
• 2023

In this study, real-time damage evaluation of cable-stayed bridges was conducted for cable damage. ICP type acceleration sensors were used for real-time damage assessment of cable-stayed bridges, and Kinetic Energy Optimization Techniques (KEOT) were used to select the optimal conditions for the location and quantity of the sensors. When a structure vibrates by an external force, KEOT measures the value of the maximum deformation energy to determine the optimal measurement position and the quantity of sensors. The damage conditions in this study were limited to cable breakage, and cable damage was caused by dividing the cable-stayed bridge into four sections. Through FE structural analysis, a virtual model similar to the actual model was created in the real-time damage evaluation method of cable. After applying random oscillation waves to the generated virtual model and model structure, cable damage to the model structure was caused. The two data were compared by defining the response output from the virtual model as a corruption-free response and the response measured from the real model as a corruption-free data. The degree of damage was evaluated by applying the data of the damaged cable-stayed bridge to the Improved Mahalanobis Distance (IMD) theory from the data of the intact cable-stayed bridge. As a result of evaluating damage with IMD theory, it was identified as a useful damage evaluation technology that can properly find damage by section in real time and apply it to real-time monitoring.