• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.38-45
• /
• 2020

A magnetically levitating capsule train, which runs inside the sub-vacuum tube, can reach ultra-fast speeds by dramatically reducing the aerodynamic drag and friction. The capsule train uses the superconductor electrodynamic suspension (SC-EDS) method for levitation. The SC-EDS method has advantages, such as a large levitation gap and free of gap control, which could reduce the infra-construction cost. On the other hand, disadvantages, such as the large variation of the levitation-guidance gap and small damping characteristics in levitation-guidance force, could degrade the running stability and ride comfort of the capsule train. In this study, a dynamic analytical model of a capsule train based on the SC-EDS was developed to analyze the running dynamic characteristics. First, as important factors in the capsule train dynamics, the levitation and guidance stiffness in the SC-EDS system were derived, which depend non-linearly on the velocity and gap variation. A 3D dynamic analysis model for capsule trains was developed based on the derived stiffness. Through the developed model, the effects of the different running speeds on the ride comfort were analyzed. The effects of a disturbance from infrastructure, such as the curve radius, tube sag, and connection joint difference, on the running stability of the capsule train, were also analyzed.

• Journal of Yeungnam Medical Science
• /
• v.10 no.1
• /
• pp.197-211
• /
• 1993

Recently, the Supracondyle fracture of the femur is so severe and comminuted that it is difficult to treat open reduction and rigid fixation sufficiently due to violent traffic accident and external forces. The associated injuries are accompanied variously. So complications of the supracondyle fractures including joint stiffness, delayed union, infection are serious. However development of internal implant and operation skill result in relatively satisfactory function than conservative management. The authors reviewed 20 cases of the supracondyle fracture of the femur treated at Yeungnam University Hospital from 1989, Dec. To 1992, Jan. The results were as follows : 1. The male was common(70%). The 2nd-4th decade was most(87%). 2. The most common cause of injuries was traffic accident. The rate of open fracture was 35%, most of it was traffic accident. 3. According to the ASIF group classification. 4 cases were type A, 4 in type B, 12 in type C (10 in type $C_2$&$C_3$). 4. Accompanied injuries included multiple fractures in 9 cases and femoral artery injury in 1 case. 5. Among the 20 cases, conservative treatment was done in 5 cases and operative treatment was done in 15 cases. 6. Functional results (by Schatzker criteria) were as follows. The satisfactory results were achieved in 40% of cases in conservative treatment and 67% in operative treatment. 7. The average time of partial weight bearing was 15 weeks. 8. Complications were knee stiffness in 6 cases and 4 in delayed union.

• Journal of Biomedical Engineering Research
• /
• v.31 no.3
• /
• pp.217-226
• /
• 2010

The lower limb orthosis with a pneumatic rubber actuator, which is intended for the assistance and the enhancement of muscular activities of lower limbs was developed in this study. Compared to other knee extension assistive devices being developed by other researchers, our device is designed especially for the elderly people and intended only for slight assistance so that the subjects can keep their muscular strength. For the effectiveness of system, muscular activities of major muscles in lower limbs during sit-to-stand (STS) and squat motion were measured and analyzed. Subjects were performed the STS and squat motion with and without lower limb orthosis. We made comparison muscular activities between with and without lower limb orthosis. Lower limb orthosis was controlled using muscular stiffness force feedback that is controlled by muscular activities of the measured muscle from force sensor. For analysis of muscular activities, electromyography of the subjects was measured during STS and squat motion, and these were measured using MP 150(BIOPAC Systems, Inc.). Muscles of interest were rectus femoris(RF), vastus lateralis(VL), vastus medialis(VM) and vastus intermedius(VI) muscles in lower limbs of the right side. A biodex dynamometer was used to measure the maximal concentric isokinetic strength of the knee extensors of wearing and not wearing orthosis on right side. The test were performed using the concentric isokinetic mode of test with the velocity set at 60°/s for muscles around the knee joints. The experimental result showed that muscular activities in lower limbs wearing orthosis using muscular stiffness force of a vastus medialis muscle was reduced and knee extension torque of an knee joint wearing lower limb orthosis was increased. With this, we confirmed the effectiveness of the developed lower limb orthosis.

• Journal of Distribution Science
• /
• v.4 no.1
• /
• pp.121-140
• /
• 2006

This study has explored a number of problems arising from distribution restrictions and the ways to improve efficiency. As matters stand, since the cooperation between larger stores and local retailers is limited due to the nature of the market, the current situations call for bottom up restrictions such as the active promotion of smaller merchants and traditional marketplaces, the enhancement of the competitiveness of smaller merchants and manufacturers through the establishment of a customized consulting support program for individual shops, and the continual support for traditional marketplaces with facilities and management modernization. The government should maintain the optimal balance between the efficiency and effectiveness of the distribution industry through such bottom up restrictions as shown above, rather than the top down restrictions primarily relying on the hurdles to the establishment of stores. The problems raised in this study include: (i) the decline of traditional marketplaces and the alleged over saturation of stores; (ii) the possible abuse of indiscreet restrictive measures; (iii) the harmful effects of the monopoly or oligopoly by larger distributors; and (iv) the lack of systematic programs to promote development. The ways to improve efficiency are: (i) the establishment of the policies to specialize and nurture traditional marketplaces; (ii) the effort to prevent the injury arising from monopoly; (iii) the two tire strategies for the coexistence of larger and smaller businesses; and (iv) the administration of joint sales promotion and training.

• Journal of Distribution Science
• /
• v.11 no.12
• /
• pp.13-23
• /
• 2013

Purpose - There is a dominant opinion that medium and small enterprises in the Korean economy have not developed qualitatively but only towards quantitative growth and, therefore, the unbalanced structure between large enterprises and those that are medium and small has worsened. In particular, this rapid industrialization causes after-effects such as polarization as well as anti-business sentiment, the collapse of the middle class, and hostility against the establishment. The consensus contends that it is difficult for Korea to be an advanced nation without resolving these problems. This paper attempts to suggest a co-prosperity model by limiting the focus to business relations with medium and small manufacturers (with regard to investment among the various co-prosperity institutions of POSCO). These co-prosperity institutions have been established in POSCO; however, it is thought that the development of a co-prosperity model regarding investment in medium and small manufacturers will help many needy investment manufacturers. Research design, data, and methodology - This study analyzes research on the co-prosperity model, using it to examine Korean cases and foreign cases. The co-prosperity model has been continuously extended but is determined to be seriously insufficient. The purpose of this study is to develop the Korean co-prosperity model by reinterpreting it in various aspects. In order to develop the Korean co-prosperity model, this study suggests the case of the establishment of the co-prosperity model by POSCO with medium and small manufacturers with regard to investment. This model is expected to be presented to many enterprises as the future co-prosperity model. Results - To date, analysis of the co-prosperity model itself and the co-prosperity model through the case of POSCO have been suggested. As empirical studies on co-prosperity in Korea are not sufficient, successful models of co-prosperity should be developed in various aspects in future. It is expected that through this study, medium and small manufacturers would have an opportunity to find various growth engines by actively using the cooperation platform and establishing optimized competitiveness of steel material through a steel business model. The ecosystem of enterprises may evolve and be healthier by making more joint products through productive business relationships between large enterprises and those that are medium and small. From the enterprises' ecosystem viewpoint, cooperation between such businesses rather than one-way support is identified as an essential element for the security of inter-competitiveness. Conclusions - Infrastructure should be established to form a dynamic industry ecosystem not by transient efforts in co-prosperity, but by an entire culture of co-prosperity across industries. In this respect, the leading role of public institutions needs to be intensified initially. In addition, the effects of co-prosperity should be extended to blind spots of policies such as third party companies and regions. A precise co-prosperity monitoring system should be established to continuously conduct and extend these efforts.

• Journal of Korea Technology Innovation Society
• /
• v.10 no.2
• /
• pp.230-254
• /
• 2007

Scientometrics means the metrics of science, and it plays a role in the measurement of scientists' activities by using research results like papers. Objective numerical values or indicators obtained by scientometric analysis may make a significant contribution to correct evaluation by excluding political or relationship bias or revealing significant researchers or their research fields that have been assessed relatively lower for their performance. In the period when the scale of technology was relatively large, such as for the development of heavy chemistry, it was possible to make a not-bad selection by an assessment made only with the intuition of the assessor. However, it is nearly impossible for experts with a narrow knowledge in a field to judge the direction of change correctly as the current science technology changes rapidly and tremendously. Even in an assessment of research performance of researchers or research institutions, only some notable researchers are able to attract attention owing to the Metthew effect, and the majority who have accumulated research results in depth are not able to receive reasonable research funding. Therefore, it might be natural that there is a growing need for assessment using scientometrics. The purpose of this research is to suggest some applicable scientometric techniques for an assessment of research performance to science and technology researchers and policy planners. In order to accomplish this, we used a frequency analysis of papers and its citations to assess the research performance of researchers, institutions, and countries for OLED technology as a case study. Furthermore, we position detailed technologies for OLED technology as arriving, growing, maturing, and declining technology by utilizing several network analysis techniques, make groups with researchers and institutions of same research interest. And we review the current international joint research of Korea, China, and Japan, who are in a competitive relationship. Also, at the end of each analysis result, we describe what kind of assessment should be available to Korean policy planners and research managers for such scientometric analysis results.

• International Journal of Highway Engineering
• /
• v.13 no.4
• /
• pp.103-115
• /
• 2011

Concrete slab curls and warps due to the uneven distribution of temperature and moisture and as the result, internal stress develops within the slab. Therefore, environmental loads must be considered in addition to the traffic loads to predict the lifespan of the concrete pavement more accurately. The strength of the concrete slab is gradually decreases to a certain level at which fatigue cracking is generated by the repetitive traffic and environmental loadings. In this study, a new fatigue regression model was developed based on the results from previously performed studies. To verify the model, another laboratory flexural fatigue test program which was not used in the model development, was conducted and compared with the predictions of other existing models. Each fatigue model was applied to analysis logic of cumulative fatigue damage of concrete pavement developed in the study. The sensitivity of cumulative fatigue damage calculated by each model was analyzed for the design factors such as slab thickness, joint spacing, complex modulus of subgrade reaction and the load transfer at joints. As the result, the model developed in this study could reflect environmental loading more reasonably by improving other existing models which consider R, minimum/maximum stress ratio.

• Journal of the Korean Society for Advanced Composite Structures
• /
• v.2 no.4
• /
• pp.1-10
• /
• 2011

This study investigates the performance of composite (steel-concrete) frame structures through numerical experiments on individual connections. The innovative aspects of this research are in the use of connections between steel beams and concrete-filled tube (CFT)columns that utilize a combination of low-carbon steel and shape memory alloy (SMA) components. In these new connections, the intent is to utilize the recentering provided by super-elastic shape memory alloy tension bars to reduce building damage and residual drift after a major earthquake. The low-carbon steel components provide excellent energy dissipation. The analysis and design of these structures is complicated because the connections cannot be modeled as being simply pins or full fixity ones they are partial restraint (PR). A refined finite element (FE) model with sophisticated three dimensional (3D) solid elements was developed to conduct numerical experiments on PR-CFT joints to obtain the global behavior of the connection. Based on behavioral information obtained from these FE tests, simplified connection models were formulated by using joint elements with spring components. The behavior of entire frames under cyclic loads was conducted and compared with the monotonic behavior obtained from the 3D FE simulations. Good agreement was found between the simple and sophisticated models, verifying the robustness of the approach.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.2 no.1
• /
• pp.39-44
• /
• 2006

Cerebral palsy(CP) is one of the most common motor disease, due to brain injury during fetal and neonatal development which results in neuromotor paralysis and associated neuromuscular symptoms. Features of CP include motor disability due to the lack of muscle control, often accompanied by sensory disorders, mental retardation, speech disorders, hearing loss, epilepsy, behavior disorders, etc. There are increasing chances of treatment of dental patients with cerebral palsy, as the occurrence of CP is increasing with the decrease in infant mortality and an increase in immature birth and premature birth and also, there is a trend to pursue of higher quality of life. Reports on the relationship between CP and maxillofacial deformity are uncommon, but it is well known that the unbalance and discontrol of the facial muscles, lip, tongue and the jaws leads to malocclusion and temporomandibular joint disorders, and statistics show that class 2 relationship of the jaws and open bite is frequently reported. However, it is difficult to perform maxillofacial deformity treatment, which consists of orthodontic treatment, maxillofacial surgery and muscle adaptation training, due to difficulties in communication and problems of muscle adaptation caused by difficulties in motor control which leads to a high recurrence rate. This case report is to trearment of maxillofacial deformity in CP patient. A 26 year old female patient came to the department with the chief complaint of prognathism of the mandible and facial asymmetry. According to the past medical history, she was diagnosed as cerebral palsy 1 week after birth, classified as GMFC, classII accompanied with left side torticollis. The patient's intelligence was moderate, and there were no serious problems in communication. For two years time, the patient underwent lingual frenectomy, pre-operation orthodontic treatment and then bimaxillary orthognathic surgery to treat mandibular prognathism and facial asymmetry followed by rehabilitatory exercise of facial muscle. After 6 months of follow up, there was a good result. This is to report to the typical signs and symptoms of DFD in CP patient and the limitation of the usual method of the treatment of DFD in CP patient with literature review.

• Journal of Korea Port Economic Association
• /
• v.29 no.2
• /
• pp.173-194
• /
• 2013

This paper aims at drawing policy schemes to establish marine clusters so as to enhance Korea's global port competitiveness and applying them to its national management for the advancement of national economy through policy suggestions. The research method is an integrated approach(IA) that comprises SWOT Method with strategic approaches, HFP Model enhanced by KJ Method and descriptive deductions. Strategic schemes established for the SPLC are followed by the group of geographical proximity, integration of ICT, expansion of the interchange of ICT & opportunities of ET, integration of ICT services with marine technologies, supply of integrated services in the SPLC and implementation of organizational policies. In order to make a specific implementation of strategic establishment schemes of the SPLC, we need to select a promotion entity. It is advised to establish the joint organization of the public sector and the private sector, which is considered most desirable. In practice, it is to be followed by promoting support schemes of the organizational policy on the level of national management. In order to reinforce this study, further compensative and proactive researches on the offshore sector with marine clusters are required in terms of the development of the high value added 'blue' ocean.