• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.3
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• pp.275-281
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• 2004

Socket weldment used to change the flow direction of fluid nay have flaws such as lack of fusion and cracks. Liquid penetrant testing or Radiography testing have been applied as NDT methods for flaw detection of the socket weldment. But it is difficult to detect the flaw inside of the socket weldment with these methods. In order to inspect the flaws inside the socket weldment, a ultrasonic testing method is established and a ultrasonic transducer and automated ultrasonic testing system are developed for the inspection. The automated ultrasonic testing system is based on the portable personal computer and operated by the program based Windows 98 or 2000. The system has a pulser/receiver, 100MHz high speed A/D board, and basic functions of ultrasonic flaw detector using the program. For the automated testing, motion controller board of ISA interface type is developed to control the 4-axis scanner and a real time iC-scan image of the automated testing is displayed on the monitor. A flaws with the size of less than 1mm in depth are evaluated smaller than its actual site in the testing, but the flaws larger than 1mm appear larger than its actual size on the contrary. This tendency is shown to be increasing as the flaw size increases. h reliable and objective testing results are obtained with the developed system, so that it is expected that it can contribute to safety management and detection of repair position of pipe lines of nuclear power plants and chemical plants.

• Journal of the Korea Convergence Society
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• v.8 no.5
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• pp.79-85
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• 2017

The purpose of this research was to evaluate the clinical and the instrument of convergence utility of transient elastography (FibroScan(R):electromagnetic wave) in diagnosing and treating liver ailments through a comparison and an analysis between liver function blood test and transient elastography (FibroScan(R)) in patients with chronic hepatitis B virus infection. Of all the patients with chronic hepatitis B virus infection who visited clinic B in Daejeon City between July 1, 2015, and February 28, 2016, 75 who underwent a FibroScan(R) test were selected for this study. Their laboratory and liver function test results were compared for a correlation analysis before constructing an ROC (Receiver Operation Characteristic) curve. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were 0.572 and 0.502, respectively, and showed highest correlation with fibrosis score, with statistical significance (p<0.000). Gamma glutamyltranspeptidase, total bilirubin, and alkaline phosphatase levels also showed relatively significant correlations in this order of sequence, while -fetoprotein and total protein levels did not show any statistically significant values. Albumin (-0.449) and platelet levels (-0.373) showed negative correlations with each other and no correlation with fibrosis score (p < 0.000). As liver fibrosis worsened, the accuracy of the ROC curve increased. At the F4 stage, which is the cirrhotic stage, the largest area under the curve was observed. FibroScan(R) showed significant correlation with the ALT (serum glutamic pyruvic transaminase) and AST (serum glutamic oxaloacetic transaminase) levels in the liver function test, which is a routine test for patients with chronic liver ailments. This implies that fibrosis correlates with liver inflammation severity.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.5
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• pp.391-399
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• 2005

Laser-generated ultrasonic inspection system is a non-contact scanning inspection device with high spatial resolution and wide bandwidth. The amplitude of laser-generated ultrasound is varied according to the energy of pulse laser and the surface conditions of an object where the CW measuring laser beam is pointing. In this paper, we correct the generating errors by measuring the energy of pulse laser beam and correct the measuring errors by extracting the gain information of laser interferometer at each time. h dynamic stabilizer is developed to stably scan on the surface of an object for an laser-generated ultrasonic inspection system. The developed system generates ultrasound after adaptively finding the maximum gain time of an laser interferometer and processes the signal in real time after digitization with high speed. In this paper, we describe hardware configuration and control algorithm to build a stable laser-generated ultrasonic inspection system. Also, we confirmed through experiments that the proposed correction method for the generating errors and measuring errors is effective to improve the performance of a system.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1623-1626
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• 2005

초음파 영상 기법은 장기, 연조직, 혈류를 검사하는데 쓰이는 영상 진단법이다. 초음파 장비를 통해 얻어진 초음파 볼륨 데이터는 장비 특성상 많은 잡음(speckle noise)을 포함하기 때문에, 깨끗한 영상을 얻기 위해서는 잡음 필터링(noise filtering)이 필요하다. 그런데, 볼륨 데이터 모든 영역에 대해 잡음 필터링을 적용할 경우 전처리 시간이 길어져 실시간으로 초음파 볼륨 데이터를 렌더링하기 어렵다. 본 논문에서는 실시간으로 입력되는 초음파 볼륨 데이터를 가시화 하기위하여 전처리 시간 없이 잡음을 제거하는 방법을 제안한다. 전처리 시간에 전체 볼륨 데이터에 대해 잡음 필터링을 적용하지 않고, 영상을 생성하는 동안 참조되는 복셀(voxel)에 대해서만 잡음 필터를 적용하여 얻은 값을 사용한다. 이때 필터링에 소요되는 시간을 최소화하기 위해 가장 단순한 평균화 필터를 사용한다. 그리고 복셀에 적용되는 3차원 필터를 3단계의 1차원 필터 연산 단계로 분할 한 후, 각 단계별 연산을 거친 복셀들에 대해서는 다시 연산을 하지 않도록 하여 중복을 피한다. 이를 통해 전처리 시간 없이 기존 방법과 동일한 화질을 유지하는 최종 영상을 만들어 낸다.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.2
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• pp.93-97
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• 2009

An advantage of a magnetostrictive strip transducer for a long-range guided wave inspection is that the wave patterns are relatively clear and simple when compared to a conventional piezoelectric ultrasonic transducer. Therefore, if we can characterize the evolution of defect signals, it could be a promising tool for a structural health monitoring of pipes for a long period of time as well as an identification of flaws. However, when evaluating a signal during a realistic field examination, it should be careful because of some spurious signals or false indications, such as signals due to a directionality, multiple reflections, mode conversion, geometrical reflections etc. Mode converted signals from a realistic piping mockup were acquired and analysed. We found mode conversions between a torsional guided wave T(0,1) mode and a flexural F(1,3) or longitudinal L(0,2) mode generated by a magnetostrictive strip transducer. Based on the experimental observations, an interpretation of the source of the mode conversion is discussed in a viewpoint of electromagnetic properties and structure of the strip transducer.

• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.705-713
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• 2020

Arteriosclerosis is a disease in which blood circulation is impaired due to loss of elasticity as blood vessels become narrower, and is a potential cause of recently increasing cardiovascular and cerebrovascular diseases. Carotid ultrasound is used as a predictor of cardiovascular and cerebrovascular diseases by evaluating the degree of atherosclerosis. Therefore, this paper attempted to investigate the correlation between the increase in the thickness of the inner media and various clinical variables in carotid ultrasound. Patients with carotid ultrasound findings were classified into three stages: mild intima thickening, sclerosis, and significant stenosis. CAVI (Carotid Ankle Vascular Index: vascular age) data measured in the degree and physical characteristics of the carotid artery(gender, age, body mass index, blood pressure), blood test(total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, creatine phosphokinase, fasting blood sugar), and arteriosclerosis test were collected. It was confirmed that the carotid intima thickness was correlated with variables such as hypertension, hyperlipidemia, and BMI, and also correlated with the risk factors of cardiovascular disease as CAVI increased.

• Journal of Veterinary Clinics
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• v.33 no.1
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• pp.39-42
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• 2016

A 10 months old, male Poongsan dog was referred with a history of right forelimb lameness due to hit by a car a few hours before presentation. On the physical examination, the dog showed pale mucous membrane, respiration distress, and skin abrasions. The main laboratory finding was leukocytosis, while hematocrit was normal. Abdominal radiography revealed the loss of abdominal serosal detail, which was diagnosed as peritoneal hemorrhage on ultrasonography (US) and aspiration. On computed tomography (CT), hepatic and splenic injuries were seen characterized by the discontinuity of the capsule with irregular margin and lower density lesions than parenchyma. No contrast enhancing area were shown in the laceration lesion. The accessory spleen was incidentally found by US and CT. In this case, acute intra-abdominal hemorrhage from splenic and hepatic laceration was diagnosed using CT.

• The Journal of the Korea Contents Association
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• v.9 no.3
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• pp.185-194
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• 2009

This research attempted to find risk factors of alcoholic liver diseases by ultrasonography at the K image medicine clinic center located in Kwangju city, Kyunggi-Do from March to May, 2007. Six risk factors were selected for this study, age, sex, frequency of alcohol drinking, body mass index(BMI), cholesterol and GPT. The data collected from 353 patients of aged between 20 and 69. This study found the relationships between liver diseases and alcohol drinking style by liver ultrasonography. The results of the analyses showed that the male were 2.12 times more likely to have liver diseases than the female. The persons drinking alcohol more than 3 times per week had 2.37 times higher likelihood of showing liver diseases than below 2 times per week or non drinking at all.. The persons with normal body mass index have 0.52 times lower probability of liver diseases than the persons with abnormal BMI. The persons with abnormal cholesterol level have 9.13 times higher probability of liver diseases. The persons with abnormal GPT have 4.66 times higher probability of liver diseases. The results of this study suggested applying ultrasonography in health promotion programs for diagnosis of liver diseases.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.1 no.1
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• pp.1-5
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• 2008

Purpose: We studied the diagnostic value of dynamic US in the extensor tendon dislocation at the metacarpophalangeal joint. Materials and Methods: From January 2007 to October, we studied 6 cases that had been diagnosed and followed over 5 months (2-10) in average. US examination using a 10-MHz linear transducer were performed in three cases. The causes of dislocations were traumatic in 5 cases and congenital in one case. Results: In only 3 cases which could not be diagnosed clinically, we performed US. In dynamic US, all three cases showed the extensor tendon dislocation evidently. Operative findings were sagittal band rupture in 4 cases, capsular loosening in one case and sagittal band thinning in one case. Sagittal band repair was performed in 4 cases and capsular augmentation in one case. In case of congenital dislocation showing 4 digital extensor tendon dislocations in right hand, we operated only the second extensor by sagittal band repair with augmentation by looping. At last follow-up, no case showed recurrence or limitation of motion. Conclusion: In case of extensor tendon dislocation without apparent clinical finding, US with dynamic study has so great value that it can detect the dislocation in real time, which is superior to MRI.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.305-310
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• 2016

Recently as the ultrasonography became generalized, the annual change rate of the incidence of thyroid cancer extraordinarily grew to 24.5% in Korea. Therefore, the aim of this study was performed to identify the risk factors of thyroid cancer apart from conventional risk factors of dietary iodine and ionizing radiation. In this retrospective study, 411 patients underwent fine-needle aspiration biopsy were examined from January 2011 to March 2013. The subjects are divided into two groups which are 260 patients with benign nodule and 151 patients with malignancy nodule. We compared age, hematologic values, body mass index, waist circumference, menopausal status, breast nodules status, uterine myoma status, fatty liver status of targeted group of patients. According to the result, in thyroid cancer group with obesity, the number of case of breast nodules and myoma was higher, and their thyroid stimulating hormone values was higher than the benign nodule group. In order to establish factors influencing thyroid and thyroid cancer, there is a definite need for continuous study.