• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.1-14
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• 1996

Since the publication of the first bone scintiscans in 1962 three decades have elapsed. The bone scan has made great strides during this period, becoming one of the most commonly used nuclear imaging tests. In spite of the progress, however, the specificity of bone scan has remained relatively low. As the result it is a common practice to seek additional information from radiograph, CT scan and MR image, which is euphemistically termed as "image fusion or co-location." The basic reason is the inapplicability of the classical piecemeal analysis to interpreting planar and SPECT bone scans. Such analysis has its base on the observation of elemental features of morphology, which include the size, shape, contour, location, topography and internal architecture. The physiochemical profile may well also be included. Understandably, however, the miniatured images of the planar bone scan cannot provide these features in acceptable detail and the same holds true even with SPECT Images which are but sliced views of the reconstructed planar scans. Fortunately pinhole scanning has the capacity to portray both the morphological and chemical profiles of bone and joint diseases in greater detail through true magnification. The magnitude of pinhole scan resolution is practically comparable to that of radiography as far as gross anatomy is concerned. Thus, we feel strongly that pinhole scanning is a potential breakthrough of the long-lamented low specificity of bone scan. This presentation will discuss the fun-damentals, advantages and disadvantages and the most recent advances of pinhole scanning. It high-lights the actual clinical applications of pinhole scanning in relation to the diagnosis of infective and inflammatory diseases of bone and joint.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.2 s.146
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• pp.213-219
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• 2006

Low cycle fatigue cracks are mainly detected at discontinuous welded locations with high stresses under repeated cyclic static loads due to cargo leading and unloading. Theoretical and analytical methods have been used for evaluation of local stress and strain which have an effect on a prediction of fatigue life, but those have difficulties of considering stress concentration at notched location and complicated material behavior of welded joint or heat affected zone. Electronic speckle pattern interferometry(ESPI) system is nondestructive and non-contact measurement system which can get the relatively accurate full field strain at critical positions such as welded zone and structural discontinuous location. In this study, local strain was measured on welded cruciform joint by ESPI system and then low cycle fatigue test was performed. Effect of local strain on low cycle fatigue life was examined by measured values using ESPI system. Moreover, experimental fatigue life was compared with established S-N curves using theoretical local strain and stress calculated by Neuber's rule.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.1251-1258
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• 2003

This paper is a study on the pedal placement and driving position of forklift according to the various body dimensions. Comfortable driving position were measured angles of joint(ankle, knee, hip) by Goniometer. From SIP(seat index point) to basis of pedals were measured about X and Y axises. In addition, Z axises were gauged between floor and pedals. In this paper, The 27 male subjects with no experience in driving forklift were measured in the test in order to exclusion of learning effect. Therefore the subjects have a preference for pedal location to the body dimensions, if as long as their body dimensions was very long, they would required each pedal's location of Y axis to increase. However, driving position is no influence. The pedal location of X and Z axises weren't related with various body dimensions and subjects have symmetrical location to the pedals of inching and break and hight of brake pedal is lower than the others. They hope that brake pedal is lower than others.

• Journal of KIBIM
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• v.11 no.2
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• pp.43-53
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• 2021

The 'public agency oil joint purchase system' was introduced to lower public sector oil prices and contribute to the stability of the overall consumer oil market. The present study used spatial regression to analyze the factors affecting domestic gasoline price, focusing on the impact of potential implicit collusion among gas stations in determining domestic gasoline prices. Also, this study investigated the effect the location characteristics of the market convention gas stations and government offices on the pressure of price competition in the market and the gasoline price at general gas stations. To summarize the results of the spatial lag model (SLM), the individual characteristics of gas stations such as convenience stores (+), self-fuelling (-), commercial areas (+), subway stations (+), population density (-), and sales (-) are correlated to gasoline prices at gas stations, and the institutional location factors of gas stations (+) affected the average of 9 won per liter, 11 won per liter. In order to solve these problems, the establishment of a monitoring system reflecting the location characteristics of the region and the ongoing review of the system should be carried out. In addition, separate, expanded and promotional measures should be prepared for the convenience of general and public oil buyers.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.2
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• pp.235-250
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• 1990

Thirty-nine patients (forty-four joints) who had been diagnosed as having meniscus perforation of the temporomandibular joint by inferior joint space arthrography and had been treated by surgical procedures were evaluated retrospectively. Information of clinical findings, arthrotomographic findings and surgical findings was collected on a standardized form and evaluated. The results were as follows: 1. On the 34 patients of 38 joints which were surgically confirmed perforation of meniscus or its attachments of the temporomandibular joint, there were 29 females and 5 males (5.8:1). The average age was 36 years (range 17 to 70). 2. The common clinical findings of group that had meniscus displacement without reduction and with perforation were pain on the affected joint and limitation of mouth opening. In the group showing meniscus displacement with reduction and with perforation the common clinical findings were pain and clicking on the affected joint. 3. 32 joints (84.2%) were arthrotomographically anterior meniscus displacement without reduction and with perforation, 6 joints (15.8%) showed anterior meniscus displacement with reduction and with perforation. 4. Joints categorized arthrotomographically as having meniscus displacement without reduction and with perforation were less likely to have full translation of the condyle in comparison with the normal or meniscus displacement with reduction and with perforation groups. (p<0.05) 5.The arthrographic findings of 44 joints having meniscus perforation were compared with surgical findings, there were 6 false positive findings of meniscus perforation, the reliability of arthrographic findings of meniscus perforation was a 86.4% correlation with surgical findings. 6. On the site of perforations of 38 joints which were surgically confirmed perforation of meniscus or its attachments, twenty-three of perforations (60.5%) were in location at the junction of the meniscus and posterior attachment, forteen (36.9%) were located at the posterior attachment and one (2.6%) was at the meniscus itself.

• Composites Research
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• v.23 no.1
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• pp.37-43
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• 2010

In this paper, we present the result of an experimental investigation pertaining to the structural behavior of bolted lap-joint connection of pultruded fiber reinforced plastic structural shapes. In the experimental investigation, in order to find the mechanical property of the material, tension and shear tests on the pultruded structural composite specimen are conducted prior to the investigation on the structural behavior of bolted lap-joint connection of the member. Based on the result, number of bolts, type of placement and location of bolt are determined to be a test variable. Three different types of experimental specimens are prepared. Tensile load is applied through the center of the specimen with lap-joint connection and the structural behavior and failure mode of the test specimens with respect to the tensile load increment are investigated. As a result, it is found that most of the failure mode at the lap-joint connection is shear failure mode. Consequently, it is also found that the data obtained through this experimental program could be used for the structure connection design as a basis.

• Imaging Science in Dentistry
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• v.51 no.2
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• pp.149-154
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• 2021

Purpose: This study aimed to investigate the computed tomography and magnetic resonance imaging features of giant cell tumors in the temporomandibular joint region to facilitate accurate diagnoses. Materials and Methods: From October 2007 to June 2020, 6 patients (2 men and 4 women) at Yonsei University Dental Hospital had histopathologically proven giant cell tumors in the temporomandibular joint. Their computed tomography and magnetic resonance imaging findings were reviewed retrospectively, and the cases were classified into 3 types based on the tumor center and growth pattern observed on the radiologic findings. Results: The age of the 6 patients ranged from 25 to 53 years. Trismus was found in 5 of the 6 cases. One case recurred. The mean size of the tumors, defined based on their greatest diameter, was 32 mm (range, 15-41 mm). The characteristic features of all cases were a heterogeneously-enhancing tumorous mass with a lobulated margin on computed tomographic images and internal multiplicity of signal intensity on T2-weighted magnetic resonance images. According to the site of origin, 3 tumors were bone-centered, 2 were soft tissue-centered, and 1 was peri-articular. Conclusion: Computed tomography and magnetic resonance imaging yielded a tripartite classification of giant cell tumors of the temporomandibular joint according to their location on imaging. This study could help clinicians in the differential diagnosis of giant cell tumors and assist in proper treatment planning for tumorous diseases of the temporomandibular joint.

• Geomechanics and Engineering
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• v.30 no.3
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• pp.281-291
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• 2022

Complex rock masses include various joint planes, bedding planes and other weak structural planes. The existence of these structural planes affects the mechanical properties, deformation rules and failure modes of jointed rock masses. To study the influence of the parameters of a nonpersistent joint network on the mechanical properties and failure modes of jointed rock masses, synthetic rock mass (SRM) technology based on discrete elements is introduced. The results show that as the size of the joints in the rock mass increases, the compressive strength and the discreteness of the rock mass first increase and then decrease. Among them, the joints that are characterized by "small but many" joints and "large and clustered" joints have the most significant impact on the strength of the rock mass. With the increase in joint density in the rock mass, the compressive strength of rock mass decreases monotonically, but the rate of decrease gradually decreases. With the increase in the joint dip angle in rock mass, the strength of the rock mass first decreases and then increases, forming a U-shaped change rule. In the analysis of the failure mode and deformation of a jointed rock mass, the type of plastic zone formed after rock mass failure is closely related to the macroscopic displacement deformation of the rock mass and the parameters of the joints, which generally shows that the location and density of the joints greatly affect the failure mode and displacement degree of the jointed rock mass. The instability mechanism of jointed surrounding rock is revealed.

• Journal of Korean Foot and Ankle Society
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• v.26 no.4
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• pp.163-170
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• 2022

Purpose: The proximal fifth metatarsal fracture is one of the most common foot fractures. However, few studies have evaluated the associated injuries in patients with a proximal fifth metatarsal fracture. The purpose of this study was to investigate the incidence of foot and ankle joint injuries associated with proximal fifth metatarsal fractures and compare the incidence of these injuries based on the injury mechanisms and location of the fracture. Materials and Methods: This retrospective study included 157 patients with a proximal fifth metatarsal fracture who underwent surgery from January 2014 to August 2021. Their medical records and radiology images were reviewed to classify and analyze the associated injuries. The proximal fifth metatarsal fractures were classified using Lawrence and Botte's classification. Injury mechanisms were divided into direct and indirect injuries. The incidence of injuries was statistically analyzed according to the injury mechanism and classification. Results: Of the 157 patients with proximal fifth metatarsal fractures, 81 (51.6%) were diagnosed with foot and ankle joint injuries. The incidence of foot injuries was 65.4%, that of ankle joint injuries was 19.8%, and of both foot and ankle joint injuries was 14.8%. In patients with direct injuries, the incidence of foot and ankle joint injuries was 82.5% and that of indirect injuries was 41.0%. Statistical differences were observed between the incidence of direct and indirect injuries (p<0.001). The incidence of injuries, according to Lawrence and Botte's classification, was 54.9% (Zone I), 41.2% (Zone II), and 50.0% (Zone III) respectively. However, there were no statistically significant variations in the locations of the proximal fifth metatarsal fractures (p=0.051). Conclusion: In this study, the incidence of foot and ankle joint injuries associated with proximal fifth metatarsal fractures was found to be high. Therefore, a careful physical examination and appropriate radiological evaluation are recommended for patients with such fractures.

• Journal of the Korean Society of Hazard Mitigation
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• v.2 no.4 s.7
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• pp.131-141
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• 2002

Precast concrete (PC) panels are often used as retaining walls to support soil pressure. In such a case, the panels should be connected at the location where PC panels meet with a buttress. However, it is not easy to provide enough development length for the reinforcing steels due to the limited width of the buttress. If it happens, the width of buttress should be increased as large enough although it is not desirable. The critical section required for providing the development length is always located where the flexural moment is maximum. Thus it is the place the buttress width ends. Also it is the place that the reinforcing steels stressed to maximum. However, it is possible to make differentiate between the maximum moment location and the most stressed location of reinforcing steels. It means that the most stressed location of reinforcing steels, the critical section, can be moved to the other place where the moment is not maximum. New critical location will have less moment than that of buttress width ends. In consequence, the development length would be longer than that of the typical way of construction. Debonding or cutting technique make it possible to reduce the moment strength of a section. Therefore reinforcing steels are debonded or cut to have a desired flexural strength at a desired place. In this study, five test specimens in full scale were erected to examine the effects of critical section movement in PC panel joints. Test parameters were the length variations of debonded and cut reinforcing steels. The test results showed that the debonding or cutting technique could be used to lengthen the development length in the joint of PC panels.