• Journal of Acupuncture Research
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• v.17 no.4
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• pp.79-87
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• 2000

Objectives : To evaluate the findings useful for differential diagnosis and associated abnormaiities of isthmic spondylolisthesis and degenerative spondylolisthesis on CT. Materials and methods : We reviewed retrospectively the CT images of 65 patients who were diagnosed spondylolisthesis during 3 years period. Our technique was 5mm slices at 5mm intervals with gantry angle to parallel the interspaces. Also reformatted sagittal views were taken. 41 patients were isthmic spondylolisthesis and 24 patients were degenerative spondylolisthesis. Resuits : Isthmic spondylolisthesis. 1. Isthmic type was more common at L5-S1. 2. The degree of anterior displacement was grade I and II. 3. The plane of defect was more horizontal than the usual facet joint. 4. The defect had an irregular shape. 5. Medial aspect of bone just anterior to defect had a small round prominence. 6. Anteroposterior elongation of the spinal canal was common. 7. Pseudobulging disk was common. 8. The most common associated abnormality was a HNP at the upper level of the defect. Degenerative spondylolisthesis. 1. Degenerative type was more common at L4-5. 2. The degree of anterior disptacement was grade I and II. 3. The Plane of facet joint was oriented obliquely instead of horizontally. 4. The posterior facet(inferior facet of superior vertebra) was anteriorly displaced. 5. Bony spur of the posterior portion of anterior facet was seen. 6. The facet joints often contain gas(vaccum phenomenum). 7. The most common associated abnormality was a HNP at the level of the displacement. Conclusions : CT is a highly accurate and most sensitive technique for recognition, differential diagnosis of isthmic and degenerative types and the detection of associated abnormalities.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.13-26
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• 2013

This study is about development of technology system for MIS(Minimally Invasive Surgery) robot of S. Korea analysed by the application of scenario planning. MIS robot industry receive attention as a new growth industry for national and international and is noticeable for the leading industry of future era in Korea. In this paper was examined the characteristics of an MIS robot technology and its components. It was investigated about the technology of an overseas MIS robot(especially U.S.A) and Korean domestic MIS robot and understood such as the country's policy propulsion issues then, was searched about development direction of the future. As a result, the future policy for MIS robot of S. Korea is to further spur the development of new MIS robot technology and more improvement of the technology level of MIS robot with AR(Augmented Reality) display.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.761-768
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• 2001

Objective : To describe the underlying causes, surgical results, and prognostic factors in thoracic stenosis causing myelopathy, retrospective analysis for 28 cases of thoracic stenosis with surgery was performed Materials & Method : Twenty-eight patients(male, 15 ; female, 13) who underwent decompressive surgery for thoracic stenosis between 1987 and 1997 were analyzed. The mean age was 49 and the mean follow-up was 30.6 months. Statistical analysis with $SPSS^{(R)}$ was performed. Chi-square test was used for the analysis of relationship between subjects and multivariate analysis with general linear model was used to find prognostic factors. Result : Degenerative spondylosis was the most common cause, and three cases were associated with systemic diseases. Decompressive laminectomy was done in 23 cases, anterior decompression in four cases, and combined decompression in one case. Ossification of ligamentum flavum was found in 18 cases, facet hypertrophy in 13, ossification of posterior longitudinal ligament in six, and ventral spur in four. Postoperatively, 16 patients improved functionally and 4 patients worsened. The group of which initial symptom duration was less than two years showed better result(p=0.003). The group with sufficient decompression and no additional proximal stenosis had better outcome(p=0.002, p=0.001). Conclusion : Chronic myelopathy caused by thoracic stenosis can be reversible with appropriate decompression.

• The Journal of the Acoustical Society of Korea
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• v.21 no.8
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• pp.766-771
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• 2002

In this study, we have developed a 3-dimensional diagnostic ultrasonic sector probe using a convex type ultrasonic probe with 128 active elements. The probe was made to operate at the center frequency of 4.5㎒ with the bandwidth of 66%. The driving part was designed to rotate the axis of the convex probe by means of a step motor equipped with reduction gears and spur gears attached to the motor so that the probe could enable us to acquire a series of 2-dimensional images to construct a 3-dimensional image. Acoustic cover of the probe was made of polymers to have the same radius of rotation as that of the convex probe. The controllability of the rotation angle and the structural stability of the probe were confirmed through experimental 3-dimensional images obtained using the developed 3-dimensional sector probe.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.127-138
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• 1991

A gear forming method by cold extrusion and an analytical method with its numerical solution program based on the upper bound method were developed. In the analysis the involute curve was as a shape of die and the upper bound method was used to calculate energy dissipation rate. By this method the power requirement and optimum conditions necessary for extruding helical(spur) gear were successfully calculated. These numerical solutions are in good agreement with experimental data. In the experiment, 4-6 class helical gear of KS standard for automobile transmission was successfully manufactured.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.3
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• pp.591-599
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• 1994

A design system for power transmission bevel gears(straight, zerol, and spiral) is developed, in which the strength and durability of bevel gears can be estimated and the size of bevel gears can be minimized by introducing optimal techniques. The size of bevel gear pair as the object function to be minimized is the volume of equivalent spur gear pair at mean normal section, and the design variables to be determined are considered as the number of teeth, face width, diametral pitch, and spiral angle in spiral bevel gear. The strength(bending strength, pitting resistance) according to the AGMA standards, geometrical quantities, and operating characteristics(interference of pinion, contact ratio, etc.) are considered as the constraints in design optimization. The optimization with these constraints becomes nonlinear problem and that is solved with ALM(Augmented Lagrange Multiplier) method. The developed design method is applied to the example designs of straight, zerol, and spiral bevel gears. The design results are acceptable from the viewpoint of strength and durability within the design ranges of all other constraint, and the bevel gears are designed toward minimizing the size of gear pair. This design method is easily applicable to the design of bevel gears used as power transmitting devices in machineries, and is expected to be used for weight minimization of bevel gear unit.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.8
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• pp.20-26
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• 2001

In this paper, the charge pump PLL using the dual PFD to improve the trade-off between acquisition behavior and locked behavior is proposed. This dual PFD consists of a positive edge triggered PFD and a negative edge triggered PFD. The proposed charge pump shows that it is possible to overcome the issue of the charge pump current imsmatch by the current subtraction circuit. Also, this charge pump can suppress reference spurs and disturbance of the VCO control voltage. The proposed charge pump PLL is simulated by SPICE using 0.25${\mu}m$ CMOS process parameters.

• Journal of the Korean Geographical Society
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• v.40 no.5 s.110
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• pp.533-552
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• 2005

Human capital and higher education have been increasingly emphasized with the rise of a knowledge-based economy. Cities are recognized as places to attract human capital and spur economic development. Educated workforce supply is one of the critical parts to sustain IT industries, which have been leading recent economic development. This paper examines factors affecting geographies of educated workforce supply from colleges and universities to companies in U.S. metropolitan areas through questionnaire survey and interviews with IT companies and IT-related programs at colleges and universities. The results show that: (1) physical proximity between IT companies and colleges/universities enhances the degree of educated workforce supply from colleges/universities to IT companies; (2) IT companies which seek more specialized and rarer expertise recruit the workforce from colleges or universities over longer distance; (3) colleges and universities which offer a higher degree have geographically more extensive supply of educated workforce to IT companies than those which offer a lower degree; and (4) large IT companies have more geographically extensive supply of educated workforce to colleges/universities than small IT companies.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.881-895
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• 2012

Micro-robots are utilized as useful tools in diagnosis and treatment of various human diseases. At present, lots of countries are developing and making many micro-robots. Government of S. Korea are trying to push ahead with the plan as technology policy, for the same reason. So this study examined about micro-robot technology development and trend of S. Korea, by using the method of SWOT(Strength-Weakness-Opportunity-Threat) analysis. As a result, the future policy for micro-robot of S. Korea is to further spur the development of new micro-robot technology and more improvement of the technology level of micro-robots registered by patent as 'micro-robot of bacterium base for lesion treatment' and 'micro-robot moved by compressive fluid'. Finally, It was already confirmed as high level, technology of 'micro-robot of bacterium base for lesion treatment' and 'micro-robot moved by compressive fluid' invented at S. Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.1
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• pp.1-18
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• 2013

The elements that determine the success of development projects on goats and the prerequisites for ensuring this are discussed in the context of the bewildering diversity of goat genetic resources, production systems, multifunctionality, and opportunities for responding to constraints for productivity enhancement. Key determinants for the success of pro-poor projects are the imperatives of realistic project design, resolution of priorities and positive impacts to increase investments and spur agricultural growth, and appropriate policy. Throughout the developing world, there exist 97% of the total world population of 921 million goats across all agroecological zones (AEZs), including 570 breeds and 64% share of the breeds. They occupy a very important biological and socioeconomic niche in farming systems making significant multifunctional contributions especially to food, nutrition and financial security, stability of farm households, and survival of the poor in the rural areas. Definitions are given of successful and failed projects. The analyses highlighted in successful projects the value of strong participatory efforts with farmers and climate change. Climate change effects on goats are inevitable and are mediated through heat stress, type of AEZ, water availability, quantity and quality of the available feed resources and type of production system. Within the prevailing production systems, improved integrated tree crops - ruminant systems are underestimated and are an important pathway to enhance C sequestration. Key development strategies and opportunities for research and development (R and D) are enormous, and include inter alia defining a policy framework, resolution of priority constraints using systems perspectives and community-based participatory activities, application of yield-enhancing technologies, intensification, scaling up, and impacts. The priority for development concerns the rainfed areas with large concentrations of ruminants in which goats, with a capacity to cope with heat tolerance, can be the entry point for development. Networks and networking are very important for the diffusion of information and can add value to R and D. Well formulated projects with clear priority setting and participatory R and D ensure success and the realisation of food security, improved livelihoods and self-reliance in the future.