• Journal of Korean Neurosurgical Society
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• v.61 no.2
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• pp.194-200
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• 2018

Objective : Sometimes a vertebral artery (VA) enters the spinal canal via the C1-2 intervertebral space, a variation regarded as a C2 segmental-type VA. This paper describes the anatomy of the C2 segmental-type VA and reviews its clinical importance. Methods : Between March 2014 and November 2015, 3386 patients underwent computed tomographic angiography. I identified C2 segmental-type VAs, associated vascular variation, the origin of ipsilateral posterior inferior cerebellar arteries (PICAs), and the clinical symptoms associated with C2 segmental-type VAs. The origin of an ipsilateral PICA is divided into 5 types. A type 1 PICA originates from ipsilateral VAs coursing suboccipitally (IVASO), a type 2 originates from ipsilateral proximal C2 segmental-type VAs, a type 3 originates from ipsilateral distal C2 segmental-type VAs. For type 4, the PICA does not originate from an ipsilateral VA. For type 5, the PICA is the terminal end of an ipsilateral C2 segmental-type VA. Results : One hundred thirteen patients had 121 C2 segmental-type VAs; 47 were associated with an IVASO, and 74 were not. Four type 1, 13 type 2, 60 type 3, 42 type 4, and two type 5 PICAs were identified. Only one patient showed symptoms associated with a C2 segmental-type VA, being a 71-year-old man presenting with a C2 segmental-type VA infarction. Conclusion : For C2 segmental-type VAs, the ipsilateral IVASO and origin of the PICA are important for predicting the outcome of this type of VA infarction.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.53-59
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• 2011

A connection was made between a single stretcher and 2 headers with 2 threaded nails (Type-A), and another one between 2 stretchers and 2 headers with 4 threaded nails (Type-B) to use as specimens. Type-C was the stretchers that are connected with 2 threaded nails by half lap joint at end-distance 5D to reinforce Type-B, Type-C1 the stretchers that are connected by half lap joint at end-distance 10D, and Type-C2 with 3 threaded nails at end-distance 10D. Compressive shear strength of Type-C, the supplementation of Type-B, was decreased by 30%, compared with that of Type-B. Those of Type-B and Type-C1 that used longer end-distance than Type-C were about the same, and that of Type-C2 connected with 3 threaded nails was 1.28-times stronger than that of Type-C1. Connection of the retaining wall using existing square timber has a problem between long and short stretchers and 2 headers. So it was investigated in the experiment to replace it. Therefore, if Type-B is replaced with Type-C2 in constructing the retaining wall, the crack and the rupture of timber caused by threaded nail as well as construction period can be reduced, and also it can be expected to increase their own strength.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.4
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• pp.9-15
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• 2012

In this paper, the bearing strengths and fracture behaviors of the pin-jointed carbon fiber/epoxy composites were investigated through pin loading test with acoustic emission technique. The composites were fabricated by a filament winding process, and three types of laminated patterns were considered. Type 1 was fabricated with stitch, Type 2 was fabricated without stitich and Type 3 was fabricated with prepregs. According to the results, bearing strength of Type 1 was 3.3% lower than that of Type 2 and that of Type 3 was highest. Type 1 and Type 2 revealed a net-tension failure mode, respectively, whereas Type 3 pattern exhibited a bearing failure mode. Also, acoustic emission energy of the Type 3 was higher than that of the Type 1 and Type 2. Therefore, the Type 3 was found to be structurally safer than the Type 1 and Type 2.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.32-42
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• 1995

Cultivation using rain shelter is very popular in summer because rain shelter has a simple structure using less materials than any other regular greenhouse. Although it has a main advantage of easy construction in terms of labour, time and cost, it has some disadvantage of poor ventilation and rain fall inflow. Therefore, the rain shelters being able to overcome the problems, to some extent, are necessary to propagate for practical purpose. Three characteristic types of rain shelter were analyzed using measured and simulated environment data. Type 1 was a conventional type with an arched roof, and Type 2 and Type 3 were improved ones which were designed to have three arched roofs and three sawtooth like roofs with the openings for ventilation, respectively. The distribution of inside temperature measured was relatively uniform in Type 2 and 3 by the natural ventilation through the openings of the roof compared to Type 1 which had no openings. The relative light transmittance measured in Type 2 and 3 showed lower than that in Type 1, which suppressed the rise of inside temperature, For more accurate comparison, the differences between inside and outside temperatures to various wind speeds were calculated by the model. The difference in Type 1 was the greatest at lower wind speed below 1 ㎧, that is, the highest in inside temperature, but decreased rapidly as wind speed increased above 1 ㎧. Measured temperatures generally showed the same trends as calculated ones by the model. As a whole, the improved rain shelters(Type 2 and 3) showed better performance than the conventional one in ventilation as well as inside temperature.

• Journal of the Korean Magnetics Society
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• v.24 no.1
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• pp.1-10
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• 2014

$Co_2Z$-type barium ferrites ($Ba_3Co_2Fe_{24}O_{41}$) were synthesized using variation method. First, M-type, $Co_2Y$-type and $Co_2Z$-type synthesized by hydrothermal method. Second, M- and Y-type precursors for synthesis of $Co_2Z$ hexaferrite by hydrothermal and ball milling method. the morphology, structure and magnetic properties of the barium ferrite particles were characterized using XRD, FESEM, VSM, impedance. As a result, Single phase of M-type and $Co_2Y$-type were obtained. Manufactured powders of M+Y ball milling, M+Y hydrothermal were similar to single phase of $Co_2Z$-type hexaferrite, all powders were obtained theoretical magnetization (50 emu/g). The largest initial permeability were obtained $Co_2Z$ hexaferrite synthesized by reagent precusor, With increasing calcination temperature was lowered the initial permeability. In another synthesis didn't almost that little change could be found.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.317-320
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• 2008

본 논문에서는 Type-1 퍼지 논리 시스템과 Type-2 퍼지 논리 시스템을 설계하고, 불확실한 정보를 갖는 입력 데이터에 대하여 각각의 성능을 비교한다. Type-1 퍼지 논리 시스템은 외부잡음에 민감한 단점을 가지고 있는 반면, Type-2 퍼지 논리 시스템은 불확실한 정보를 잘 표현할 수 있으며 효율적으로 취급한다. 따라서 Type-2 퍼지 논리 시스템을 이용하여 이러한 단점을 극복하고자 2가지의 모델을 설계한다. 첫 번째 모델은 규칙의 전 ${\cdot}$ 후반부가 불확실성을 표현 할 수 없는 Type-1 퍼지 집합으로 구성된 Type-1 퍼지 논리 시스템을 설계한다. 두 번째는 규칙 후반부만 Type-2 퍼지 집합으로 구성한 두가지의 Type-2 퍼지 논리 시스템을 설계한다. 여기서 규칙 전반부의 입력 공간 분할에는 Min-Max 방법의 균등분할을 사용하고, 규칙 후반부 멤버쉽 함수의 중심 결정에는 입자 군집 최적화(Particle Swarm Optimization) 알고리즘을 사용하여 동정한다. 또한 입력 데이터에 인위적으로 가하는 노이즈의 정도에 따른 각각 모델의 성능을 비교한다. 마지막으로 비선형 모델 평가에 주로 사용되는 가스로 시계열 데이터를 제안된 모델에 적용하고, 실험을 통하여 불확실한 정보를 다루기에 Type-1 퍼지 논리 시스템 보다 Type-2 퍼지 논리 시스템이 효율적이라는 것을 보인다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1847-1848
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• 2008

본 논문에서는 Type-2 퍼지 논리 시스템을 설계하고, 불확실한 정보를 갖는 입력 데이터에 대하여 Type-1 퍼지 논리 시스템과 성능을 비교한다. Type-1 퍼지 논리 시스템은 외부 잡음에 민감한 단점을 가지고 있는 반면, Type-2 퍼지 논리 시스템은 불확실한 정보를 잘 표현 할 수 있다. 따라서 Type-2 퍼지 논리 시스템을 이용하여 이러한 단점을 극복 하고자 한다. 본 논문에서는 실험을 통하여 기존의 Type-1 퍼지 논리 시스템 보다 Type-2 퍼지 논리 시스템이 효율적 이라는 것을 보인다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1624-1632
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• 2009

In this study, we introduce the design methodology of an optimized Interval Type-2 fuzzy controller. The fixed MF design of type-1 based FLC leads to the difficulty of rule-based control design for representing the linguistically uncertain expression. In the Type-2 FLC as the expanded type of Type-1 FLC, we can effectively improve the control characteristic by using the footprint of uncertainty(FOU) of membership function. Type-2 FLC has a robust characteristic in the unknown system with unspecific noise when compared with Type-1 FLC. Through computer simulation as well as practical experiment, we compare their performance by applying both the optimized Type-1 and Type-2 fuzzy cascade controllers to ball and beam system. To evaluate each controller performance, we consider controller characteristic parameters such as maximum overshoot, delay time, rise time, settling time and steady-state error.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.321-324
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• 2008

Type-2 퍼지 집합은 Type-1 퍼지 집합에서는 다루기 어려운 언어적인 불확실성을 더욱 효과적으로 다룰 수 있다. TSK 퍼지 로직 시스템(TSK Fuzzy Logic Systems; TSK FLS)은 Mamdani 모델과 함께 가장 널리 사용되는 FLS이다. 본 연구의 Interval Type-2 TSK FLS 모델은 전반부에서 Type-2 퍼지 집합을 이용하고 후반부는 계수가 상수인 1차식을 사용한다. 전반부의 파라미터는 오류역전파 방법(Back-propagation)을 통한 학습으로 결정되고, 후반부 파라미터(계수)들은 Least squre method(LSM)를 사용하여 결정된 값을 사용하여 모델을 구축한다. 본 논문에서는 Type-1 TSK FLS과 Type-2 TSK FLS의 성능을 가스로 공정 데이터를 적용하여 비교 분석한다. 또한 랜덤 화이트 가우시안 노이즈를 추가한 테스트 데이터를 사용하여 노이즈에 대한 성능을 분석한다.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.187-193
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• 1996

This experiment was conducted to investigate the influence of temperature variation by the different ventilation methods on the growth and quality of oriental melon in greenhouse of tunnel type 1. The dropping effect in temperature by ventilation types was best at type 3 and those of type 2, type 1 were in order. 2. The temperature distribution in type 3 was uniformed as air- inflow and air- outflow by wind ventilation were easier than others. Whereas the temperature of type 1 having lateral ventilation hole and type 2 having the zenith ventilation tube and lateral ventilation hole was ascended, because small ventilation area of ventilation tube and hole could not make the gravity and wind ventilation successfully. 3. When compared with air amount of three types ventilated by the temperature difference of outside and inside of tunnel type house, that of type 3 was more than those of type 1 and type 2. 4. Type 3 was better than type 2 and type 1 in lear numbers, leaf area, fruit weight, flesh thickness, malformed fruit rate, and marketable fruit rate. 5. Marketable fruit rate of all treatment at each harvesting stages was rised, as goes to the latter periods.