• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.34 no.4
• /
• pp.183-189
• /
• 2021

In recent years, active research has been devoted toward developing a monitoring system using ambient vibration data in order to quantitatively determine the deterioration occurring in a structure over a long period of time. This study developed a low-cost edge computing system that detects the abnormalities in structures by utilizing the dynamic characteristics acquired from the structure over the long term for ensemble learning. The system hardware consists of the Raspberry Pi, an accelerometer, an inclinometer, a GPS RTK module, and a LoRa communication module. The structural abnormality detection afforded by the ensemble learning using dynamic characteristics is verified using a laboratory-scale structure model vibration experiment. A real-time distributed processing algorithm with dynamic feature extraction based on the experiment is installed on the Raspberry Pi. Based on the stable operation of installed systems at the Community Service Center, Pohang-si, Korea, the validity of the developed system was verified on-site.

• The Journal of Korean Academy of Prosthodontics
• /
• v.61 no.4
• /
• pp.328-343
• /
• 2023

Recently, a method of fabricating an esthetic anterior fixed prosthesis by integrating data such as three-dimensional facial scan and jaw motion to form a virtual patient with dynamic occlusion has been introduced. This enables smooth communication with patients during the diagnosis process, improves the predictability of esthetic prosthetic treatment, and lowers the possibility of occlusal adjustment. In this case report, a virtual patient with dynamic occlusion was created in which the results of the treatment were simulated, and esthetic maxillary anterior fixed prosthesis was fabricated. With the aid of the virtual patient, the final restorations were satisfactory both in terms of esthetic and function.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1766-1769
• /
• 2005

Air-operated valve(AOV) is one of principal valves that are using to control fluid flow in nuclear power plants. AOV is suffered from damage and malfunction by the abrasion, corrosion and vibration of valve parts under the long time operation. This mechanical trouble and malfunction of valve is critical for the safety of power plant. So a periodic diagnosis for safety of power plants is inevitable to guarantee the safety of the power plant. But depending on the type of the actuator and valve body, various types of AOV exist. In this study, It is developed the diagnostic system that users of power plants are easy to handle in this paper.

• Journal of Korean Institute of Industrial Engineers
• /
• v.24 no.2
• /
• pp.297-309
• /
• 1998

Numerical parameters have been developed to diagnose L4/L5 disc patients during repetitive flexions and extensions. Electromyography(EMG) has been used to define the muscle excitation and movement cycle in this study. Twenty healthy subjects and twenty L4/L5 disc patients were recruited for the experiment. The subjective pain levels of patients were recorded as $3.7{\pm}1.6$ according to visual analogue scale where 10 was the maximum pain level. Variance ratio of motion cycle was suggested as a new parameter to examine the consistency of the trunk movement. The results indicated that the temporal EMG pattern such as peak time difference between Quadriceps and Hamstrings, the duration of coexcitation between Erector spinae and Rectus abdominis muscle pairs showed a statistically significant difference between healthy subjects and patients. Variance ratio of External oblique and Internal oblique also showed a statistically significant difference. It is expected that those results could be used for diagnosis by building a database for various back pain patients and healthy subjects. This method can eventually help physicians for early diagnosis and prevention of low back disorders.

• Clinical and Experimental Pediatrics
• /
• v.52 no.9
• /
• pp.1038-1043
• /
• 2009

Two adolescent cases of Fitz-Hugh-Curtis syndrome, which has not been previously reported in Korean girls, presenting with right upper-quadrant abdominal pain, nausea, vomiting, and fever are reported here. A careful and thorough inquiry into the sexual history of the first patient, which was not done upon admission, led to a careful reassessment of the dynamic abdominal computed tomography scan revealing hepatic capsular enhancement without evidence of gallbladder or liver disease. Both cases were diagnosed noninvasively and were treated successfully by medical intervention. A high index of suspicion of Fitz-Hugh-Curtis syndrome should be implemented in the differential diagnosis of right upper quadrant pain, particularly in sexually active girls, for a prompt diagnosis and rapid cure.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.6
• /
• pp.2759-2764
• /
• 2014

Aim: This study aims to investigate the manifestation of CT, MRI and dynamic enhanced scans for primary hepatic neuroendocrine cell carcinoma. Methods: CT or MRI arterial and venous phase scan images of 19 cases of pathologically confirmed PHNEC were retrospectively analyzed. Results: 14 cases (73.68%) with single lesion, 5 cases (26.3%) with multiple lesions, with an average diameter of 13.2 cm. Some 12 cases (63.16%) showed inhomogeneous enhancement, seven cases (36.8%) showed homogeneous enhancement, 13 cases (68.4%) demonstrated significant enhancement in the arterial phase, 13 cases (68.4%) had significantly enhanced portal venous phase including 7 cases (36.8 %) with portal venous phase density or signal above the arterial phase and 5 cases (26.3%) with the portal vein density or signal below the arterial phase. Seven cases (36.8%) had continued strengthened separate shadows in the center of the lesion. Thrombosis were not seen in portal veins. Conclusion: CT and MRI images of liver cell neuroendocrine carcinoma have certain characteristics that can provide valuable information for diagnosis and differential diagnosis.

• Journal of Advanced Navigation Technology
• /
• v.15 no.1
• /
• pp.18-24
• /
• 2011

This paper proposes fault diagnosis system which is able to diagnose the fault from present operating condition by analyzing monitored signals with present ship monitoring system without additional sensors. For this all kinds of ship's engine room monitored data are classified with combustion subsystem, heat exchange subsystem and electric motor and pump subsystem by analyzing ship's operation data. To extract dynamic characteristics of these subsystems, log book data of container ship of H shipping company are used.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1998.04a
• /
• pp.321-327
• /
• 1998

This paper presented a case study on the application of on-line wear monitoring technique to a high duty air-turbo-compressor system. Main objects monitored were a gear unit and metal bearings, both shown frequent troubles due to the severe operation conditions at heavy dynamic load. The air-turbo-compressor system needs secure condition monitoring because it is one of the main utilities in steel making industry. Temperature and vibration characteristics have been mainly on-line monitored in this system for a predictive maintenance; however, it has been shown that they are not fairly good enough to give an early warning prior to the machine failure. In this work, an on-line Opto Magnetic Detector(OMD) was implemented for an on-line wear monitoring, which quantitatively measured the contamination level of both ferrous and non-ferrous wear particles by detecting the change in optical density of used oil. Results showed that the application of on-line OMD system was satisfactory in diagnosis of the machine system.

• Proceedings of the KIEE Conference
• /
• 2001.11c
• /
• pp.180-183
• /
• 2001

In modem city life, the citizen get insufficient exercise and has high levels of stress. Increased Stress causes such minor things as tiredness, disease and mental fatigue, and increase brain blood pressure too. In this paper trying to design the multi-functional blood pressure monitor with airo-dynamic brain hemokinesis improvement function. So this system have developed for the improvement of flows in the capillary blood vessel of head and limbs. Also This system is able to measure brain blood pressure(BBP) which need diagnosis circulation state of brain blood. So, we extracted correlativity of blood pressure(BP) and BBP through clinical experiment. We confirmed that compare factor of BP with BBP is more useful factors for diagnosis state of brain hemokinesis.

• Archives of Plastic Surgery
• /
• v.35 no.6
• /
• pp.729-734
• /
• 2008

Purpose: The evaluation and management of a completely transected tendon of the hand is relatively clear. In most cases, the integrity is assessed by physical examination(eg, broken normal cascade, motion loss) but occasionally, It happens in troubles. because of pain, limited patient cooperation(eg, child, unconscious patient), and other associated injuries(eg, fractures, foreign bodies). Methods: From september 2006 to August 2007, 28 patients were evaluated with real time ultrasonography preoperatively and postoperatively. Twenty eight patients with injured tendon were evaluated using an HDI 5000 Sono CT(Philips Medical Systems, Bothell, WA) machine with a high resolution, 7.5MHz hockey stick linear probe. Dynamic evaluation was performed in real time. Results: Surgery was performed after the ultrasonographic evaluation. Sonographic diagnosis and intraoperative findings were correlated. Ultrasonographic findings show tendon discontinuity, gaps, and fluid collection. Conclusion: We conclude that ultrasonography is helpful in evaluating and managing acute tendon injury. Especially, in cases of completely lacerated tendon, ultrasonography can identify the location of the proximal tendon stump and partial lacerated tendon, ultrasonographic diagnostic tool can decrease misdiagnosis.