• Clinics in Shoulder and Elbow
• /
• v.15 no.2
• /
• pp.138-142
• /
• 2012

Pigmented villonodular synovitis (PVNS) is a rare benign proliferative disorder that results in villous hyperplasia and nodule formation in the synovium, tendon sheath and bursa. That most commonly affects the knee and the hip joint in adult. PVNS of the hand, the wrist, the shoulder and the elbow is rare and that of the elbow in children is particularly rarer. An eight-year-old boy had his left elbow pain and a lesion like benign bone tumor in the left fossa olecrani on plain x-ray. During the operation, abnormal synovial hyperplasia in his left elbow joint led us to diagnose PVNS. Therefore, open curettage of the lesion and radical synovectomy was performed. The specimen of the synovectomized tissue revealed PVNS. The left elbow pain subsided after the operation and the child restored a full range of motion of his left elbow. We reported this rare case of PVNS in a child's elbow joint mimicking the bone tumor together with a review of the literature.

• The Journal of the Korean life insurance medical association
• /
• v.29 no.2
• /
• pp.29-32
• /
• 2010

Moyamoya disease (MMD) is a progressive occlusive disease of the cerebral vasculature with particular involvement of the circle of Willis and the arteries that feed it. MMD is one of cerebrovacular accident,which is treated with sugical maeuver in pediatic neurosurgery. Moyamoya (ie, Japanese for "puff of smoke") characterizes the appearance on angiography of abnormal vascular collateral networks that develop adjacent to the stenotic vessels. The steno-occlusive areas are usually bilateral, but unilateral involvement does not exclude the diagnosis. The exact etiology of moyamoya disease is unknown. Some genetic predisposition is apparent because it is familial 10% of the time. The disease may be hereditary and multifactorial. It may occur by itself in a previously healthy individual. However, many disease states have been reported in association with moyamoya disease, including the following: 1) Immunological - Graves disease/thyrotoxicosis 2) Infections - Leptospirosis and tuberculosis 3) Hematologic disorders - Aplastic anemia, Fanconi anemia, sickle cell anemia, and lupus 4) Congenital syndromes - Apert syndrome, Down syndrome, Marfan syndrome, tuberous sclerosis, Turner syndrome, von Recklinghausen disease, and Hirschsprung disease 5) Vascular diseases - Atherosclerotic disease, coarctation of the aorta and fibromuscular dysplasia, 6)cranial trauma, radiation injury, parasellar tumors, and hypertension etc. These associations may not necessarily be causative but do warrant consideration due to impact on treatment.(Mainly neurosurgical operation.) The incidence of moyamoya disease is highest in Japan. The prevalence of MMD is 1 person per 100,000 population. The prevalence and incidence of moyamoya disease in Japan has been reported to be 3.16 cases and 0.35 case per 100,000 people, respectively. With regard to sex, the female-to-male ratio is 1.4:1. A bimodal peak of incidence is noted, with symptoms occurring either in the first decade(5-10yr) or in the third and fourth decades (30-40yr)of life. Mortality rates of moyamoya disease are approximately 10% in adults and 4.3% in children. Death is usually from hemorrhage. In aspect of life insurance, MR is 1700%, EDR is 16 per 1000 persons. Children and adults with moyamoya disease (MMD) may have different clinical presentations. The symptoms and clinical course vary widely from asymptomatic to transient events to severe neurologic deficits. Adults experience hemorrhage more commonly; cerebral ischemic events are more common in children. Children may have hemiparesis, monoparesis, sensory impairment, involuntary movements, headaches, dizziness, or seizures. Mental retardation or persistent neurologic deficits may be present. Adults may have symptoms and signs similar to those in children, but intraventricular, subarachnoid, or intracerebral hemorrhage of sudden onset is more common in adults. Recently increasing diagnosis of MMD with MRI, followed by surgical operation is noted. MMD needs to be considered as the "CI" state now in life insurance fields.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.29 no.4
• /
• pp.180-188
• /
• 2017

Recently, as the strength of winds and waves increases due to the climate change, abnormal waves such as swells have been also increased, which results in the increase of downtime events of loading/unloading in a harbour. To reduce the downtime events, breakwaters were constructed in a harbour to improve the tranquility. However, it is also important and useful for efficient port operation by predicting accurately and also quickly the downtime events when the harbour operation is in a limiting condition. In this study, numerical simulations were carried out to calculate the wave conditions based on the forecasted wind data in offshore area/outside harbour and also the long-term observation was carried out to obtain the wave data in a harbour. A forecasting method was designed using an auto-regressive (AR) and artificial neural networks (ANN) models in order to establish the relationship between the wave conditions calculated by wave model (SWAN) in offshore area and observed ones in a harbour. To evaluate the applicability of the proposed method, this method was applied to predict wave heights in a harbour and to forecast the downtime events in Pohang New Harbour with highly complex topography were compared. From the verification study, it was observed that the ANN model was more accurate than the AR model.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.10
• /
• pp.17-26
• /
• 2010

This is concerned with the technology to monitor the vehicle operation, failure and disorder by using WiBro portable device. More precisely, the technology makes it possible that the information collection device is connected to both ECU(Electronic Control Unit) which is the device for controlling engine, transmission, brake, air-bag, etc that are connected to in-vehicle network and OBD-II connector that is for data collection from various sensors. In addition, with a WiBro portable device (cell phone, PDA, PMP, UMPC, etc). equipped with a vehicle diagnostic programs, information for operation, failure and malfunction can be obtained and analyzed in real-time, and alarm is alerted when the vehicle is in abnormal status, which makes the early reactions to the status. Furthermore, the collected data can be sent through WiBro network to the server managed by the company specialized in managing the vehicles, thus the technology could help the drivers who have less knowledge about their auto-vehicles have safe and economic driving. There is always a possibility of malfunction due to various types of noise that are caused by wring-harness when the device is wired-connected. In this research, in order to overcome this problem, we propose a system configuration that can do monitoring and diagnosis with a device for collecting data from vehicle and a personal WiBro device. Also, we performed research on data acquisition and interlock for the system defined by the definition for information and data sharing platform.

• Applied Chemistry for Engineering
• /
• v.16 no.6
• /
• pp.794-799
• /
• 2005

With the quantitative growth of the petroleum industry, the pipe facilities that connect each process increased significantly and the corresponding maintenance and repair costs of the pipe facilities increased as well. The diagnosis techniques to check a pipe efficiency while in operation are few in Korea, but in the advanced countries the pipe diagnosis using gramma-ray source was on-going research since 1960's. In this study, field experiments were performed to analyze the reasons for abnormal operation of the pipe connected to a distillation tower, and the degree of abnormality was estimated using a sealed gamma-ray source ($^{137}Cs$). Gamma radiation counts were measured by a detector (NaI) positioned outside the pipe-wall diametrically opposite to the gamma source. The results showed that a gas zone section's distribution pattern was different from the pattern of nearby fluid in a pipe. Th diagnosis technique using a gamma radiation source was proved to be an effective and reliable method, offering the information on the fluid distribution in pipe.

• Korean Journal of Labor Studies
• /
• v.24 no.2
• /
• pp.321-365
• /
• 2018

Though the British shipbuilding industry dominated the world market in the 19th century, it could not avoid the repetitive rise and fall of the unemployment following after the cyclical fluctuations. Without challenging the employers' rights to fire at will, the boilermakers maintained their own unemployment insurance in order to escape from the new poverty law system. In the beginning the craft union could continue their own unemployment insurance under the National Insurance Act of 1911, but it went into bankruptcy under the massive unemployment of the 1920s and the attacks of shipyard employers. The Act of 1911 was a step towards social solidarity in that it spread the risks beyond the occupational boundaries, applying unemployment insurance to unskilled and non-union workers, and the employer and the government also paid the premium. In the Great Depression, the shipyard trade unions demanded that the government should intervene in the shipbuilding market to provide jobs, but it was not accepted by the government. The government responded only to the another demand of the union for the maintenance, which could be achieved partially through the abnormal operation of the insurance system, abandoning the insurance principle. After all, unemployment in the shipbuilding industry was resolved only by the expansion of rearmaments and the outbreak of World War II. From the 19th century to the World War II, the craft unions did not challenge the employers' right to fire at will and did not attempt to regulate dismissal procedures or make any demands on dismissal compensations. During interwar periods rules and practices related with weak employment protection - one of the main features of the liberal employment adjustment institution - were prevalent in Britain. The principle of 'employment at will' could survive through the historical events such as the World War I, II as the operation of the unemployment insurance became the focus of the social conflicts.

• Journal of Navigation and Port Research
• /
• v.42 no.6
• /
• pp.395-405
• /
• 2018

Seakeeping safety module in Korean e-Navigation system is one of the ship remote monitoring services that is employed to ensure the safety of ships by monitoring the ship's real time performance and providing a warning in advance when the abnormal conditions are encountered in seakeeping performance. In general, seakeeping performance has been evaluated by simulating ship motion analysis under specific conditions for its design. However, due to restriction of computation time, it is not realistic to perform simulations to evaluate seakeeping performance under real-time operation conditions. This study aims to introduce a reasonable and faster method to predict a ship's roll motion which is one of the factors used to evaluate a ship's seakeeping performance by using a machine learning-based surrogate model. Through the application of various learning techniques and sampling conditions on training data, it was observed that the difference of roll motion between a given surrogate model and motion analysis was within 1%. Therefore, it can be concluded that this method can be useful to evaluate the seakeeping performance of a ship in real-time operation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2019.05a
• /
• pp.230-231
• /
• 2019

This study is a development on condition based maintenance(CBM) technology which is a core item of future autonomous ships. It is developing to design & installation of condition monitoring system and acquisition & processing of data from ongoing ships for fault prediction & prognosis of engine in operation. The ultimate goal of this study is to develop a predicts and decision support software for marine engine faults. To do this, the FMEA and fault tree analysis of the main engine should be accompanied by the analysis of classification of system, identification of the components, the type of faults, and the cause and phenomenon of the failure. Finally, the CBM system solution software could predict and diagnose the failure of main engine through integrated analysis for bid-data of ongoing ships and engineering knowledge. Through this study, it is possible to pro-actively cope with abnormal signals of engine and to manage efficiently, and as a result, expected that marine accident and ship operation loss during navigation will be prevented in advance.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.3
• /
• pp.381-389
• /
• 2019

It is important to estimate flood overflow because adverse weather phenomena are frequently occurring in recent years. In order to cope with such abnormal floods, it is essential to perform flood inundation simulations for constructing flood inundation maps as nonstructural countermeasures. However, there is no quantitative evaluation method and criterion for flood inundation prediction. In this study, the Receiver Operation Characteristics (ROC) and Lee Sallee Shape Index (LSSI) were employed to quantitatively evaluate the accuracy of flood inundation maps for 10 administrative districts. Comparing predicted inundation maps with actual inundation trace maps, the ROC score was 0.631 and the LSSI was 25.16 %. Using the ROC and the LSSI, we proposed an evaluation criterion for flood inundation map. The average score was set as an intermediate score and distributed into 5 intervals. The validity of the evaluation criterion was investigated by applying to the XP-SWMM model, which has been verified and corrected. The ROC analysis result was 0.8496 and the LSSI was 51.92 %. It is considered that the proposed evaluation criteria can be applied to flood inundation maps.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.34 no.5
• /
• pp.301-308
• /
• 2021

It is important to develop a digital SOC (Social Overhead Capital) maintenance system for preemptive maintenance in response to the rapid aging of social infrastructures. Abnormal signals induced from structures can be detected quickly and optimal decisions can be made promptly using IoT sensors deployed on the structures. In this study, a digital SOC monitoring system incorporating a multimetric IoT sensor was developed for long-term monitoring, for use in cloud-computing server for automated and powerful data analysis, and for establishing databases to perform : (1) multimetric sensing, (2) long-term operation, and (3) LTE-based direct communication. The developed sensor had three axes of acceleration, and five axes of strain sensing channels for multimetric sensing, and had an event-driven power management system that activated the sensors only when vibration exceeded a predetermined limit, or the timer was triggered. The power management system could reduce power consumption, and an additional solar panel charging could enable long-term operation. Data from the sensors were transmitted to the server in real-time via low-power LTE-CAT M1 communication, which does not require an additional gateway device. Furthermore, the cloud server was developed to receive multi-variable data from the sensor, and perform a displacement fusion algorithm to obtain reference-free structural displacement for ambient structural assessment. The proposed digital SOC system was experimentally validated on a steel railroad and concrete girder bridge.