• Journal of Biosystems Engineering
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• 제17권2호
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• pp.156-170
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• 1992

The force-deformation relationship gives the basic physical properties of the fruits such as the bioyield point, the rupture point, and the deformations at the bioyield point and the rupture point. These informations are very important to study the stress-strain relationships of the fruits. This study was conducted to analyze those physical properties according to the sampling position of the fruits, and to determine the bioyield point, the rupture point, and the deformations at the bioyield point and the rupture point of the fruits for two different storage conditions(low temperature and normal temperature) and the storage period, and to investigate the effect of loading rate on those physical properties, the hysteresis on the loading-unloading condition and the degree of elasticity of the fruits. The results of the study were as follows : 1. The physical properties(BS, US, BD, and RD) of the test specimen selected from the different sampling positions were quite different. The values of the physical properties were shown smallest ones at the cheek of the fruits, and the statistical test results of the physical properties between the cheek from the other two positions of the fruits showed that there were significant difference at the 1 % level between them. 2. The effect of loading rate on the physical properties of the fruits was relatively large, all the considered physical propertis of the fruits increased with the loading rate, but the hysteresis loss decreased with it. 3. The physical properties of the fruits according to the storage conditions and period showed different, and the bioyield deformation and the rupture deformation of the fruits increased with the storage period, but the bioyield strength and the ultimate strength of the fruits decreased with it. The effect of the storage conditions on the those physical properties showed that the normal temperature storage condition was a little higher than the low temperature storage condition. 4. As a whole, it was shown that the bioyield strength and the ultimate strength of the pear decreased a little faster than those of the apple, and the bioyield deformation and rupture deformation of the pear increased a little faster than those of apple at the two storage conditions.

• Journal of Biosystems Engineering
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• 제15권2호
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• pp.99-109
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• 1990

Rough rice is subjected to a series of static and dynamic forces during mechanical harvesting, handling and processing operations. The mechanical properties such as bioyield point, compressive strength, and deformations at the bioyield point and rupture point are important engineering data needed to develop processing machines and to determine reasonable operating conditions for these machines. The objectives of this study were to determine the mechanical properties of the rough rice kernel at loading rate of 0.664 mm/min and 1.673 mm/min and at various moisture contents, and to examine the effect of the moisture content and the loading rate on these mechanical properties. The follwing results were obtained from the study. 1. Bioyield point, rupture point, bioyield strength and ultimate strength of the rough rice kernel generally decreased in magnitude with an increase in moisture content. A little larger values of these mechanical properties were obtained at the higher loading rate. The rough rice variety and the loading rate affected significantly these mechanical properties at low moisture content, but not at the higher moisture levels. 2. Bioyield point of the sample grains varied from 20 to 80 N, and rupture point varied from 45 to 130N. Bioyield point for Japonica-type rough rice was a little higher than that for Indica-type rough rice, but there were little differnces in rupture point between two types of rough rice. 3. Bioyield strength and ultimate strength of the Japonica-type rough rice varied from 10 MPa. to 39 MPa., and from 13 MPa. to 45 MPa. respectively. Those of the Indica-type rough rice varied from 12 MPa. to 42 MPa., and from 15 MPa. to 53 MPa. respectively. 4. Deformations at bioyield point and rupture point ranged from 0.18 mm/min to 0.26 mm, and from 0.28 mm to 0.53 mm respectively. These deformations decreased with an increase in moisture content up to moisture content of approximately 17% (w.b.) and increased again thereafter. 5. Regression equations were developed to predict these mechanical properties for the rough rice kernel as a function of moisture content.

• 한국식품영양학회지
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• 제9권4호
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• pp.466-471
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• 1996

오이, 마늘, 생강, 감자 및 무의 압축특성을 규명하기 위하여 식품물성 측정기로 압축 힘, 거리 및 시간을 측정하고 이들의 상관관계를 살펴보았다. 힘-거리 및 거리-시간 곡선은 비교적 간단한 형태를 나타냈고 변곡점들이 잘 나타나지 않았다. 파괴점까지의 시간은 감자가 압축속도 60mm/min에서 11.79, 압축속도 120mm/min에서 6.16초로 가장 길었다. 마늘은 각각 9.65 및 4.55초로 적게 소요되었는데 이는 시료의 압축강도에 따른 차이 때문으로 생각된다. 파괴힘은 무와 감자는 압축속도별로 16.64∼20.00N으로 가장 컸으며, 파괴시에 시료는 탐침 밑에 뭉개어지는 거동을 보였다. 압축시험시 파괴점까지의 힘-시간과 거리-시간에 대한 회귀분석 결과 상관계수 값이 0.96이상이었으며, 시료간의 차이는 작았다. 힘-시간 곡선의 기울기는 오이와 마늘이 1.772∼3.385로 가장 켰으며, 감자가 각각 1.743 및 3.338로 작았으며, 거리-시간 곡선의 기울기와는 반비례 관계를 나타냈다.

• 한국식품과학회지
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• 제29권2호
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• pp.273-278
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• 1997

몇가지 채소류(오이, 무우, 마늘, 생강 및 감자)의 펀치특성을 살펴보기 위하여 식품물성 측정기로 일정하게 힘을 가하면서 힘-거리-시간 간의 관계를 살펴보고 성분함량 및 세포특성과의 관계를 살펴본 결과는 다음과 같다. 힘-거리 및 거리-시간 곡선 상에는 많은 변곡점 및 파괴점이 관찰되었으며, 이는 시료의 구성세포가 가해진 힘에 대해 저항 또는 항복할때 나타나는 현상으로 탐침속도가 느릴때 크고 분명하였다. 파괴점까지 힘-시간 및 거리-시간에 대한 회귀분석 결과 상관계수는 0.95이상이었다. 탐침이 시료를 관통하는 시간과 그때의 힘은 생강이 5.63초 및 4.88 N으로 컸고 오이가 4.15초 및 2.00 N으로 작았으며, 탐침속도가 빠를 수록 더 많은 파괴힘을 필요로 하였다. 상관관계 분석결과 세포가 클수록 수분함량이 많고 파괴거리가 커지며, 세포의 규칙성, 시료의 즙액, 조밀도와 힘-시간 간의 기울기는 작아지는 관계를 보였다. 비중이 클수록 파괴힘, 거리 및 시간은 작아졌으며, 거리-시간곡선의 기울기는 힘-시간곡선의 기울기와 반비례 관계가 있었다.

• Journal of Korean Neurosurgical Society
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• 제30권sup1호
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• pp.73-78
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• 2001

Objective : Intraoperative rupture of an intracranial aneurysm can interrupt a microsurgical procedure and jeopardize the patient's chance to favorable outcome. The purpose of this study was to analyse and evaluate intraoperative aneurysmal rupture and render ideal prevention and management to intraoperative rupture. Patients and Methods : The authors retrospectively analysed the results of 609 patients who underwent cerebral aneurysm surgery from January 1991 to December 2000. Results : 1) Intraoperative aneurysmal rupture occurred in 73 of 609 consecutive aneurysm surgery, so the incidence was about 12.0% and it was relatively lower than other reports. 2) Aneurysms arising from anterior communicating artery appeared more prone to intraoperative rupture. 3) The size of aneurysm and timing of operation didn't influence intraoperative aneurysmal rupture and temporary clipping didn't reduce the incidence of intraoperative aneurysmal rupture. 4) Intraoperative aneurysmal rupture occured during three specific periods : (1) dissection stage in 61%, (2) clip application stage in 29 %, (3) predissection stage in 10%. 5) In the patients with intraoperative aneurysmal rupture, surgical outcome was relatively good and there was no significant difference in outcome compared with unruptured group. Conclusion : Our suggestion for prevention methods of intraoperative aneurysmal rupture are as follows : 1) minimal brain retraction, 2) sharp and careful aneurysmal neck dissection, 3) gentle clipping with proper clip selection etc. Management methods after intraoperative aneurysmal rupture are as follows : 1) strong aspiration of bleeding point, 2) rapid application of temporary and/or tentative clip, 3) following rapid dissection of neck and proper clip application, 4) use of encircling clip etc.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.173-174
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• 2008

The four-point bending test is a widely used method to determine material parameters. The aim of the present study was to evaluate the flexural strength (or modulus of rupture) and the Weibull modulus of cordierite ceramic substrate by means of four-point bending tests. The strength data from experiments followed Weibull statistics. These data indicate that the fatigue effects are more severe when the substrate temperature in the peripheral region is near $200^{\circ}$. At temperatures well above $200^{\circ}C$ the available design strength can be as high as 65% as substrate's initial strength.

• 지구물리와물리탐사
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• 제11권2호
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• pp.137-147
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• 2008

2007년 1월 20일 발생한 '오대산지진(M = 4.8)'의 특징적인 점은 근거리 지역 관측소인 DGY(기상청 대관령, 진앙거리 = 7 km)에서 기록된 비정상적으로 높은 PGA(최대지반가속도) 관측값(< 0.1 g)이다. 한편 DGY 관측소는 진앙지인근에 위치한 매우 양호한 지진관측소(연관희와 서정희, 2007)로 분류되므로 지진파전달이나 부지증폭특성으로는 설명될 수 없으며, 고주파지진동에 큰 영향을 주는 지진원 특성인 단층파열방향성(rupture directivity)에 의한 것으로 예비 해석될 수 있다. 이 연구에서는 Boatwright (2007)의 방법을 이용하여 단층파열속도(v)의 전단파속도(c)에 대한 상대적 비(= v/c) 및 파열진행방향과의 이격각(${\theta}$, deviation angle)에 대한 함수로 주어지는 일방향 단층파열방향성(unilateral rupture directivity)을 추정하였다. 이러한 단층파열방향성을 평가하기 위해 진앙지 인근 지역의 지진관측소에 대한 점지진원 스펙트럼 모델(Boore, 2003)에 대한 예측오차를 오대산지진의 전 여진 관측자료을 이용하여 계산한 후, 본진 관측자료를 이용한 예측오차와 상대적으로 비교하였다. 본진의 전 여진에 대한 상대적인 스펙트럼 예측오차로부터 관측소별 PGA의 상대적인 크기를 추정하고 이 결과를 이용하여 오대산지진의 단층파열 방향성을 평가한 결과, 오대산지진 인근에서의 높은 PGA 관측값은 NWW-SEE 방향의 북측으로 고각을 갖는 단층면상에서 SE 방향을 따라 거의 수직하게 지표면으로 빠르게 진행된 단층파열의 영향으로 해석되었다.

• Journal of Korean Neurosurgical Society
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• 제60권2호
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• pp.250-256
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• 2017

Objective : Cases of a ruptured pericallosal artery aneurysm with a high risk of intraoperative premature rupture and technical difficulties for proximal vascular control require a technique for the early and safe establishment of proximal vascular control. Methods : A combined pterional or subfrontal approach exposes the bilateral A1 segments or the origin of the ipsilateral A2 segment of the anterior cerebral artery (ACA) for proximal vascular control. Proximal control far from the ruptured aneurysm facilitates tentative clipping of the rupture point of the aneurysm without a catastrophic premature rupture. The proximal control is then switched to the pericallosal artery just proximal to the aneurysm and its intermittent clipping facilitates complete aneurysm dissection and neck clipping. Results : Three such cases are reported : a ruptured pericallosal artery aneurysm with a contained leak of the contrast from the proximal side of the aneurysm, a low-lying ruptured pericallosal artery aneurysm with irregularities on its proximal wall, and a multilobulated ruptured pericallosal artery aneurysm with the parasagittal bridging veins hindering surgical access to the proximal parent artery. In each case, the proposed combined pterional-interhemispheric or subfrontal-interhemispheric approach was successfully performed to establish proximal vascular control far from the ruptured aneurysm and facilitated aneurysm clipping via the interhemispheric approach. Conclusion : When using an anterior interhemispheric approach for a ruptured pericallosal artery aneurysm with a high risk of premature rupture, a pterional or subfrontal approach can be combined to establish early proximal vascular control at the bilateral A1 segments or the origin of the A2 segment.

• Journal of Biosystems Engineering
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• 제14권3호
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• pp.207-214
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• 1989

In this study, impact force and angular displacement of the pendulum were measured by the load cell and potentiometer. Mechanical behavior of rough rice under impact loading was able to analyze precisely and efficiently, because measured data were accumulated and handled by the automatic data acquisition system making use of microcomputer system. Impact force and angular displacement were measured with a resolutiln of 1/1500 seconds in time. Mechanical behavior such as force and energy at rupture point of Japonica type and Indica type rough rice were measured with this system. After impact loading, the damage of rough rice was examined with the microphotograph and an allowable impact force was measured. The results obtained in this study are summarized as follows. 1. Machanical behavior of rough rice under impact loading was analyzed precisely and efficiently because measured data were accumulated and handled by this data acquisition system. 2. Rupture force and rupture energy of rough rice were appeared to be the lowest value in the range of 16 to 18 % moisture content, and rupture force and rupture energy of Japonica type were higher than those of Indica type in each level of moisture content. 3. From the result of the damage examined after the impact loading, allowable impact force was the lowest in the range of 16 to 18 % moisture content, and the value of the allowable impact force of Japonica type was higher than that of Indica type in each level of moisture content.

• 대한기계학회논문집A
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• 제30권11호
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• pp.1392-1400
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• 2006

Since the monolithic ceramic substrate was in introduced for automotive catalytic converters, the durability of the substrate has been a continuing requirement to reduce the emission, gas of vehicle. The substrate can occupy a volume as small as 82 $cm^3$ and as large as 8200 $cm^3$ to provide the required substrate for catalytic activity. The long-term durability varies with the size of the substrate from manufacture's point of view. Therefore this study presents that the response surface model using central composite design can explain size effect on the modulus of rupture in a cordierite ceramic monolithic substrate.