• Journal of Chest Surgery
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• v.13 no.3
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• pp.219-228
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• 1980

The heart block and bradyarrhythmia with or without Stokes-Adams attacks are serious, usually terminal events and the immediate mortality is very high. Stimulation with an artificial pacemaker is now an accepted form of treatment in cases of Stokes-Adams syndrome in which medication in unable to produce any lasting improvement. Permanent pacemaker therapy is indicated in these circumstances. The purpose of this report is to describe the successful use of pacemaker in 3 cases of Stokes-Adams syndromes and a case of sinoatrial block with bradyarrhythmia at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University School of Medicine. Electrode catheter was passed through the right external jugular vein and attached to the endocardial surface of the right ventricle. In case 1, fixed type generator was used at first and for the case 2, 3, 4, and case 1 at second, demand type generators were used. The bipolar electrode catheters were used for the three cases and unipolar electrode catheter for case 4. The results of immediate and late period were satisfactory.

• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.663-672
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• 2010

The pollen morphology of eleven species and three forms of the genus Rhododendron (Ericaceae) in Korea was examined using light, scanning electron and transmission electron microscopy. The pollen grains are grouped in permanent tetrahedral tetrads; viscin threads are present on the tetrads. The hexacolporate tetrads are of tricolporate monads whereby the apertures form in pairs at six points in the tetrad. The exine sculpture pattern is rugulate, scabrate or verrucate on mesocolpium but psilate, rugulate or microscabrate around the aperture on apocolpium. The exine of Korean Rhododendron pollen consists of tectum, columella, foot layer and endexine. The surface of viscin threads is more or less smooth. The threads are sometimes tangled together and occasionally divided into strands. Six types are recognized based on the pollen morphology. The types are: (1) Micranthum-type (rugulate mesocolpium and psilate apcolpium), (2) Tomentosum-type (rugulate mesocolpium and apocolpium), (3) Aureum-type (scabrate mesocolpium and rugulate apocolpium), (4) Brachycarpum-type (scabrate mesocolpium and rod shaped-microscabrate apocolpium), (5) Schlippenbachiitype (scabrate mesocolpium and round-microscabrate apocolpium) and (6) Weyrichii-type (verrucate mesocolpium).

• Magazine of the Korea Concrete Institute
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• v.14 no.5
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• pp.31-38
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• 2002

최근 환경문제에 대한 일반인의 관심고조와 함께 3D 기피현상에 따른 철근공, 거푸집공 등의 기능노동자의 부족, 고령화, 외국인노동자 고용 현상과 낮은 노동생산성은 건설업계의 심각한 현안이다. 과거에는 재료비의 비중이 높았으므로 재료의 낭비를 줄이기 위한 합리화가 추진되었다. 그러나 현재는 노무비 비율의 급격한 증대로 인하여 공기단축이나 합리화, 시스템화를 통해서 경쟁에서 생존해 나가고 있다. 건축공사 중 특히 철근 콘크리트공사는 기술의 발전이 느리고, 시공 방법도 과거의 공법을 그대로 유지하고 있는 실정이다. 건축공사비 중 구체공사의 비율은 30% 정도이고, 그 비용 중 인건비가 50% 정도를 차지하고 있기 때문에 철근 콘크리트 공사는 아직도 기술 집약적인 산업이 아닌 노동 집약적 산업으로 간주되는 결과를 초래하고 있다.(중략)

• Journal of Ecology and Environment
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• v.30 no.4
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• pp.315-318
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• 2007

Cooperative or non-territorial permanently social spiders are believed to have evolved from species showing subsocial maternal care. The transition from subsocial to cooperative social groups probably involved a transition from an outbreeding breeding system to one with inbreeding. Nepotistic recognition among siblings should facilitate the evolution of social cooperation through avoidance of inbreeding and maintenance of mutual tolerance between siblings. We conducted experiments to determine whether a mechanism for sibling recognition is present in the subsocial spider, Coelotes terrestris which displays extended maternal care in the form of food provisioning. The numbers of surviving individuals within unfed groups were observed and compared between non-sibling groups of ten spiderlings and groups of ten siblings. The number of survivors differed significantly between groups, with consistently fewer spiderlings surviving in the non-sibling groups than the sibling groups over the study period. This result suggests that sibling recognition and nepotism do occur in this subsocial species. The nepotism involved in the maternal social organization of the Coelotes might be an example of a preadaptation facilitating the evolution of permanent social life.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2073-2074
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• 2011

In this study, an algorithm for diagnosis of dc motor with winding open fault is suggested. A dc motor used in this paper, is consisted of a permanent magnet field stator, double 16-turn series winding rotating armature with 12-slot, brush and 12-commutator, etc. A current signal of dc motor which has brushes and commutatorswas considered for fault diagnosis. By commutation, this current signal shows different wave form according to the fault condition of the motor. In this study, operation of the data was easily through simplification of the current signal by the signal processing. Computation method is presented reference value($C_{dv}$) for diagnosis of winding open fault and verified through experiments that can be diagnosed using the reference value($C_{dv}$).

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.5
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• pp.222-230
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• 2005

This paper deals with the reduction of cogging torque of a outer-rotor type BLDC motor mainly used for washing machines. The motor comprises permanent magnet outer-rotor and stator with coils and core. This structure inherently produces vibration and cogging torque because of uneven reluctance according to rotation of the rotor. Up to now, adopted a type of 24 magnet pole and 36 slot-stator. This generates high main torque but accompanies comparatively large cogging torque. This paper proposes a 32-pole 36-slot type motor which reduces cogging torque remarkably. The influence of cogging torque is varied according to pole-slot combinations. The characteristic of the motor was obtained by a two-dimensional finite element method coupled with a drive circuit. The performance of the proposed model is superior to that of the existing model because of the reduction of torque ripple and the improvement of back ernf wave form.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.873_874
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• 2009

This paper presents a method for designing a high power motor that is applicable to electric vehicles. Interior Permanent Magnet (IPM) type motor which has high efficiency and high durability is selected. To apply for the electric vehicles, a form, a tire and a wheel of vehicles are considered when calculating a motor performance. After calculating a motor performance, space harmonic analysis and FEA(Finite Element Analysis) is used for designing In-Wheel motor.

• Annals of Clinical Neurophysiology
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• v.10 no.1
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• pp.33-37
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• 2008

Diabetic polyneuropathy (DPN) is the most common form of diabetic neuropathy, and causes a significant morbidity with an impact on the quality of life in the patients with diabetes. Since DPN frequently induces foot deformity and ulceration, which finally leads to foot amputation, the early detection and treatment is very important for the prevention of a permanent structural change. In the early stage of DPN, the diagnostic methods which can evaluate the function or structure of small nerve fibers should be employed because small nerve fibers are first involved in the course of DPN. However, the nerve conduction study cannot reflect the function of the small nerve fibers, and thus, has a definite limitation in the early diagnosis of DPN. For the early detection of DPN, electrodiagnostic data should be interpreted on a clinical context, along with the careful evaluation of the small nerve fiber functions using the tests such as the analysis of intraepidermal nerve fiber density.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.115-117
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• 2007

Core loss form a larger proportion of the total losses. This paper deals with the analysis on the core loss in PM generator considering the operating speed for wind power application. Using the data information from a manufacturer and nonlinear curve fitting, this paper investigates the magnetic behavior and its core losses in the stator core using the electrical steels.

• Journal of Powder Materials
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• v.24 no.3
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• pp.229-234
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• 2017

We report on a simple and robust route to the spontaneous assembly of well-ordered magnetic nanoparticle superstructures by irreversible evaporation of a sessile single droplet of a mixture of a ferrofluid (FF) and a nonmagnetic fluid (NF). The resulting assembled superstructures are seen to form well-packed, vertically arranged columns with diameters of $5{\sim}0.7{\mu}m$, interparticle spacings of $9{\sim}2{\mu}m$, and heights of $1.3{\sim}3{\mu}m$ The assembled superstructures are strongly dependent on both the magnitude of magnetic field and the mixing ratio of the mixture. As the magnitude of the externally applied magnetic field and the mixing ratio of the mixture increase gradually, the size and interspacing of the magnetic nanoparticle aggregations decrease. Without an externally applied magnetic field, featureless patterns are observed for the ${\gamma}-Fe_3O_4$ nanoparticle aggregations. The proposed approach may lead to a versatile, cost-effective, fast, and scalable fabrication process based on the field-induced self-assembly of magnetic nanoparticles.