• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.673-678
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• 2015

Terahertz dual-band frequency selective surface filters made by perforating two different rectangular holes in molybdenum have been designed, fabricated and measured. Physical mechanisms of the dual-band resonant responses are clarified by three differently configured filters and the electric field distribution diagrams. The design process is straightforward and simple according to the physical concept and some formulas. Due to the weak coupling between the two neighboring rectangle holes with different sizes in the unit cell, good dual-band frequency selectivity performance can be easily achieved both in the lower and higher bands by tuning dimensions of the two rectangular holes. Three samples are fabricated, and their dual-band characteristics have been demonstrated by a THz time-domain spectroscopy system. Different from most commonly used metal-dielectric structure or metal-dielectric-metal sandwiched filters, the designed dual-band filters have advantages of easy fabrication and low cost, the encouraging results afforded by these filters could find their applications in dual-band sensors, THz communication systems and other emerging THz technologies.

• The Journal of the Korean dental association
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• v.44 no.1 s.440
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• pp.45-54
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• 2006

Piezosurgery uses modulated ultrasonic vibration to allow controlled cuting of bony structures. delicate bony structures can be cut easily and with great precision without destruction of soft tissue. Piezosurgery can be used to harvest the chin bone for intra-oral augmentation. Maxillary sinus membrane perforation is the most common complication that occurs with the sinus elevation augmentation procedure. This complication can occur during the osteotomy, which is performed with burs, or during the elevation of the membrane using manual elevators. The purpose of this study is to introduce new surgical technique that simplifies chin bone graft and maxillary sinus surgery, thus avoiding perforating the membrane.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1999.11a
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• pp.137-140
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• 1999

시설재배시 지면피복재의 멀칭 효과로는 잡초발생 억제, 토양수분 보존, 지온상승 등이 있는데 이러한 효과를 이용해 토양수분유지는 물론 근권환경을 변화시켜 작물의 생육을 향상시키고 과실의 수량 및 품질향상을 증대시키기 위한 많은 연구가 이루어지고 있다(Bhella 1988 : Lament 1993 : Park et al,. t991). 특히, 오이는 과채류 중에서 재배기간이 비교적 짧은 작물에 속할 뿐만 아니라 노화 속도가 타 작물에 비해 빠른 문제점을 갖고 있다. (중략)

• Journal of Korean Neurosurgical Society
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• v.53 no.6
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• pp.380-382
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• 2013

We report a case of fatal duret hemorrhage (DH) in a patient with acute tentorial subdural hematoma and bilateral chronic subdural hematoma along the cerebral hemispheres. Preoperative CT angiography (CTA) revealed prominent parenchymal enhancement in the ventral pontomesencephalic area. After burr-hole drainage, a large hemorrhage developed in this area. The parenchymal enhancement in the CTA may reflect the pontomensencephalic perforating vessel injury, and may be a sign of impending DH of acute transtentorial downward herniation. Previous use of aspirin and warfarin might have potentiated the process of DH and increase the extent of the bleed.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.894-900
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• 2018

Among the soft ground improvement methods, PBD is the most common construction method because it is cheap and construction is fast. However, if the ground is rigid, additional work is required. In this study, the structural safety, natural vibration, and safety angle of the steel vertical tower structure were evaluated in the development of the PBD composite perforator which can be combined with drilling work and PBD construction. Structural safety was assessed when the wind load of 20 m/s was simultaneously applied to the PBD construction load of 20 tons, the perforating operation of 25 tons, and the wind speed of 50 m/s was applied only to the wind load. The natural frequencies were evaluated up to the sixth mode, and the safety angle was evaluated for static and dynamic safety angles.

• Journal of Korean Neurosurgical Society
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• v.66 no.1
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• pp.105-110
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• 2023

A diagnosis of an intracranial aneurysm depends on the angiographic configuration and should be cautiously differentiated from aneurysm mimics. In cases of duplicate anterior choroidal arteries (AChAs), infundibular widening of the distal minor AChA can be an aneurysm mimic. If the minor AChA with a smaller diameter is obscured angiographically due to poor contrast filling, an associated infundibular widening beside the proximal large AChA can misinterpreted as a typical AChA aneurysm in angiograms. The authors report on two such cases of duplicate AChAs with infundibular widening presenting like a typical AChA aneurysm in angiograms. Surgical exploration revealed a perforating artery emitting from the dome of the saccular lesion, confirming infundibular widening of a duplicate AChA. No reparative procedure was applied to the infundibular widening in a 48-year-old man, while two vascular outpouchings from the infundibular widening were clipped preserving the duplicate AChA in a 55-year-old woman.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.5
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• pp.494-501
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• 2000

Effectiveness of a 3-pass plate finned-tube heat exchanger is calculated using heat exchangelet method by changing the shape of fin and the arrangement of tubes. The alternative refrigerant R134a is taken in this study. Conduction between neighboring tubes along the fin is taken into account in addition to convection between the fin and the surrounding air. Governing equations are obtained by using energy balance in a small control volume containing a tube and fins. They are numerically solved following the tube. Effect of tube-to-tube conduction is investigated in single-phase and two-phase flows with various fin shapes and arrangements of tubes. Improvement of effectiveness by fin perforation is studied too. The results shows that perforating fins, increasing the number of tubes, and increasing the distance between neighboring tubes at the same fin area enhance the effectiveness.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.387-392
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• 2002

This paper presents a new scheme of neural network controller to improve the robustuous of robot manipulator using digital signal processors. Digital signal processors, DSPs, are micro-processors that are particularly developed for fast numerical computations involving sums and products of variables. Digital version of most advanced control algorithms can be defined as sums and products of measured variables, thus it can be programmed and executed through DSPs. In addition, DSPs are as fast in computation as most 32-bit micro-processors and yet at a fraction of their prices. These features make DSPs a viable computational tool in digital implementation of sophisticated controllers. During past decade it was proposed the well-established theorys for the adaptive control of linear systems, but there exists relatively little general theory for the adaptive control of nonlinear systems. Perforating of the proposed controller is illustrated. This paper describes a new approach to the design of adaptive controller and implementation of real-time control for assembling robotic manipulator using digital signal processor. Digital signal processors used in implementing real time adaptive control algorithm are TMS320C50 series made in TI'Co..

• Journal of the Korea Fashion and Costume Design Association
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• v.1 no.1
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• pp.91-107
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• 1999

The primary purpose of this study is to inquire into the characteristic of exposure presented in fashion, identify the correct concept of exposure from an aesthetic perspective, and grasp the contemporary meaning of exposure presented in fashion. As a result of study, the following findings were obtained: First, the surrealist style of fashion exhibited representations such as the relocation of the partial details, the harmonization of the natural and the artificial, the emphasis or expansion of each part of the body, and the like. It used highlighted the genital region with ornamentations or used the technique of paradoxically exposing the part of the body always covered. And it exbibited the paradoxical relationship of exposure and concealment by exposing the concealed part of the human body. Second, the post-modern style showed the complicated phenomenon that the values of several meanings such as the historic, the folk, and the like appeared in its fashion. It shares in spatiotemporal eclecticism, pluralistic characteristics and the like found in the post-modern culture. Third, the deconstructive style gets rid of the distinction between the external space and the private space by translating underwears into outer garments. It destroys clothing by tearing or perforating clothing whereby it represents the poor image. Coupled with women‘s psychology of exposure and the new generation’s way of thinking indifferent to others‘ eyes, this fashion of deconstruction occupies the great current of fashion. Deconstructive fashion gets away with the rule of ‘having to wear clothing to suit TPO(Time, Place and Occasion), the traditional norm of wearing clothing.

• Journal of Nutrition and Health
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• v.29 no.6
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• pp.608-614
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• 1996

This study was performed to investigate the influcence of mugwort on the duodenal ulcer induced by cysteamine administration in rats. Five groups of rats were fed each experimental diet containing 0%, 5%, 15%, 30% of mugwork powder for 10 weeks. Duodenal ulcer was induced by cysteamine injection (400mg/100g body weight) after 10 weeks of feeding experimental diets (C-0, C-5, C-15, C-30). Control animal that fed 0% mugwork powder added diet were injected saline (S-0) to compare with cysteamine injected groups. When the duodenal ulcer induced by cysteamine-HCI administration, all animals in the C-0 group formed erosion and perforating ulcer was found in 44% of animals. Higher the added mugwork ratio, more inhibited of the duodenal ulcer induced by cysteamine administration (C-5, C-15). But when the ratio of added mugwort is 30%, the inhibition effect disappeared (C-30). The alkaline phospatase activities were lower at the duodenal mucosa and small intestinal mucosa in the cysteamine treated groups(p<0.05). The acid phophatase activities were higher at the stomach, small intestine and large intestine of the cysteamine treated groups. But in mugwort added diet group, the changes of enzyme activites were lessended. The maltast activities were lower at the duodental mucosa and small intestinal mucosa of cysteamine treated groups. But in mugwort added diet group, maltase activites were recovered.