• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.4
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• pp.361-370
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• 2003

In this study, the performance of water tightness of water expansional sealing material and gasket was evaluated. The water tightness test was performed varying the type of inner pressure condition, for which the water expansional sealing material was inundated for 5 days to evaluate the ability of water tightness. In order to carry out this test, we made use of two types of water expansional sealing material; general type and combined type with non-expansional rubber. In the case of gasket, EPDM gasket and complex gasket sticked to the water expansional sealing material were applied. The performance of water tightness depended on the construction defect and the deformation of segment. The construction defect and segment deformation were generally expressed by gap and offset of the construction joint. The results, of tests showed that the performance of water tightness was largely influenced by the gap between segments. Management criteria of gap and offset were proposed.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.8 no.1
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• pp.39-47
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• 2013

Objectives : The purpose of this study is to find out the relationship between hip internal rotation angle and the level of herniation of lumbar intervertebral disc(HIVD) in single-segment. Methods : We investigated 314 patients (158 male, 156 female) who were diagnosed as herniation of lumbar intervertebral disc(HIVD) in single-segment. We measured 314 patients' hip internal rotation angle and analysed the relationship between the hip internal rotation angle and the level of herniation of lumbar intervertebral disc(HIVD). Results : 1. Among 314 cases, the hip internal rotation angle was different between male and female. Hip internal rotation angle of male was mainly limited and that of female was mainly excessive. 2. Among 314 cases, the normal group, defined as patients who have specific range of hip internal rotation angle(male : $35^{\circ}{\pm}10^{\circ}$, female : $45^{\circ}{\pm}10^{\circ}$), tends to be occurred HIVD at L4/5 level. The limited group, defined as patients who have less angle than normal group, the excessive group, defined as patients who have more angle than normal group, and the complex group, defined as patients who have more angle of one leg and less angle of the other leg than normal group, tend to be occurred HIVD at L5/S1 level(p<0.05). Conclusions : In single-segment lumbar HIVD patients, The normal hip internal rotation angle mainly leads to L4/5 HIVD, while the limited and excessive hip internal rotation angle mainly lead to L5/S1 HIVD.

• Korean Business Review
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• v.6
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• pp.135-152
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• 1993

The optional market segmentation pricing policy for rooms of hotels are investigated under the assumption of a linear demand function, and for four different situations: (1) single price market, (2) optimal segmentation of the unused capacity of a single-price-maeket, (3) optimal segmantation for all rooms, and (4) opimal segmentation for infiltration from higher priced to adjacent lower priced segments. The purpose of tis study is th show that with proper pricing policy, it would be possible to increase profits considerably. Such a profit increase might be achived by market segmentation coupled with product differentiation, where the different market segments are identified, sperated, and in each segment a different price per room is called for. The different prices are determined based on the specific price elasticity typical for each market segment and the relavant costs. The pricing model implied in this study is based on basic economic pricing theory and optimization techniques. While somewhat complex in its mathmatical solution, it can be easily programmed for use by practitioners, avoiding the need to cope with the technical aspects of the solution. In section II-1, the optimal single-market Single-price policy is evaluated. The optimal strategy under the constraint that only the previously unutilized rooms are segmented is analysed in section II-2, while the optimal strategy without this constraint is determined in section II-3. In section II-4, the optimal market-segmentation pricing policy is derived for the case in which market seperation is allowed for all the rooms under the assumption of custtomer infiltration from each market segment to the adjacent lower priced segment Finally, some considerations relating to the practicality of the model as a decision support tool and the requirements for its implementation are discussed in section III.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.369-374
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• 2010

The shortest path between two points inside a simple polygon P is a minimum-length path among all paths connecting them which don't pass by the exterior of P. A linear time algorithm for computing the shortest path in a general simple polygon requires triangulating a polygon as preprocessing. The linear time triangulating is known to very complex to understand and implement it. It is also inefficient in case that the input without very large size is given because its time complexity has a big constant factor. In this paper, we present the customized shortest path algorithm for a segment-visible polygon which is a simple polygon weakly visible from an internal line segment. Our algorithm doesn't require triangulating as preprocessing and consists of simple procedures such as construction of convex hulls, so it is easy to implement and runs very fast in linear time.

• Journal of Korean Neurosurgical Society
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• v.46 no.6
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• pp.568-571
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• 2009

Accessory middle cerebral artery (MCA) is an infrequent vascular anomaly of the brain. Cerebral aneurysms associated with this anomalous artery are also very rare. To our knowledge, there have only been ten previous reports of an aneurysm associated with accessory MCA. The authors present two patients with accessory MCA-related aneurysms. A 38-year-old male and a 59-year-old female both presented with sudden-onset severe headache. In both patients, computed tomography (CT) scan revealed subarachnoid hemorrhage. A subsequent angiogram demonstrated an accessory MCA arising from the anterior cerebral artery (ACA) and a saccular aneurysm at the anterior communicating artery (ACoA) complex associated with an accessory MCA. Surgical clipping allowed for complete exclusion of the aneurysm from the arterial circulation. Based on our review of the ten cases of aneurysms associated with accessory MCA documented in the literature, we suggest that accessory MCA-related aneurysms can be classified according to whether the accessory MCA originates from the proximal A1 segment or from the ACoA complex. We also emphasize the importance of precise interpretation of preoperative angiograms and intraoperative precaution in determining the presence of this anomalous artery prior to temporary clip placement.

• Wind and Structures
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• v.20 no.5
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• pp.683-699
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• 2015

Lighting poles and antenna masts are typically high, slender and light structures. Moreover, they are often characterized by distributed eccentricities that make very complex their shape. Experience teaches that this structural type frequently suffers severe damage and even collapses due to wind actions. To understand and interpret the aerodynamic and aeroelastic behavior of lighting poles and antenna masts, this paper presents the results of static and aeroelastic wind tunnel tests carried out on a complex prismatic element representing a segment of the shaft of such structures. Static tests are aimed at determining the aerodynamic coefficients and the Strouhal number of the test element cross-section; the former are used to evaluate the critical conditions for galloping occurrence based on quasi-steady theory; the latter provides the critical conditions for vortex-induced vibrations. Aeroelastic tests are aimed at reproducing the real behavior of the test element and at verifying the validity and reliability of quasi-steady theory. The galloping hysteresis phenomenon is identified through aeroelastic experiments conducted on increasing and decreasing the mean wind velocity.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.114-119
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• 1997

Natural vibration of the rotor system having multi-step cross-sections is analyzed. The rotary inertia and the shear deformation are considered. Torque is also included in order to simulate the power transmission system. The complex displacement and the variable separation are introduced. The exact solutions in uniform cross-section segment and the boundary conditions are used. Natural frequencies and mode shapes are obtained, especially the mode shapes are countinuous.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.407-408
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• 1999

본 연구에서는 서울, 인천, 수원을 포함한 수도권 전지역을 대상으로 SO$_2$ 농도를 가우시안모델인 ISCST3(Industrial Source Complex for Short Term-3)로 예측하고자 한다. ISCST3 모델의 적용 영역이 넓으면 모델영역 내에서 기상조건이 상이하기 때문에 지금까지 이루어진 대부분의 연구들은 공간적으로 제한된 지역을 대상으로 해왔다.(중략)

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.109-114
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• 1987

In this thesis, we work on the curve recognition with real time processing and the Robot tracking method on recognized curve. Image information of segment curve is supplied to computer to run to a Robot so that it is a feedback system. Image coordinate frame to world coordinate transformation represents in this paper and curve matching algorithm subscribes by two method, first transformation matching algorithm, second image coordinate matching algorithm. Also Robot running time to computer image processing time relationships finally includes.

• Animal cells and systems
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• v.1 no.3
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• pp.429-434
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• 1997

A new genus with a new species of poecilostomatoid copepod, Polyankylis orientalis, is described based on a pair of specimens collected from a tide pool on muddy shore in Korea. It represents a new family of the lichomolgoid complex with the following distinguishing characters: (1) 6-segmented antennule (resulted from the fusion of the third and fourth segments) with additional aesthetascs in male, (2) hook on mediodistal corner of antennal coxobasis (first segment), (3) proximal and distal scales on the outer margin of mandible present, (4) main axis of mandibular gnathobase short and lacking notches at the base of mandibular lash, and (5) inner margin of mandibular lash with denticulate processes. Additionally, maxillar syncoxa carries a large, pointed process on ventral surface, legs 1-4 do not show sexua1 dimorphism, and leg 4 is uniramous with 1-segmented exopod. A detailed discussion is given of its affinities with the ten existing families of the lichomolgoid complex.