• Journal of Institute of Control, Robotics and Systems
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• v.13 no.2
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• pp.101-107
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• 2007

A coaxial rotor flying robot is developed for surveying and reconnoitering various circumstances under calamity environment. The robot has two contrarotating rotors on a common axis, an embedded microcontroller, an IMU(Inertial Measurement Unit), an IR sensor for height control, a micro camera for surveillance, ultrasonic position sensors and wireless communication devices. A bell-bar mounted on the top of the upper rotor hub increases stability and improves flight performance. In this paper, we present a dynamic model of a coaxial rotor flying robot and design an embedded controller far the robot, and implement them to control the developed flying robot. Experimental results show that the proposed controller is valid for autonomous hovering and position control.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.594-601
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• 1997

Propeller fans are commonly equipped in outdoor units of air-conditioners to provide effective cooling in a dried heat exchanger. A new design technique was developed to satisfy requirements of aerodynamic and aeroacoustic performance, which employs the intersection method of two cylinders for mean camber line. Three proto-types of propeller fan including Palm-Shaped, Highly-Swept(PSHS) fan (proto 3)were not only to provide low lift forces for dipole sound, but also to reduce the organized tip vortices interacting with the fan guide causing narrow-banded rotating instabilities. Cross-correlation technique was applied to study flow noise source characteristics for three proto-type fans designed. The cross-correlations between a microphone at far field and a hot-wire sensor at near field show that flows near hub region of proto 3 fan are less organized and the flow structures especially at high flow rate coefficients for proto 3 fan are less correlated with noise generated than other proto-types fans.

• Proceedings of the KIEE Conference
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• 2004.05a
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• pp.77-79
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• 2004

Because robot hardware architecture generally is consisted of a few sensors and motors connected to the central processing unit, this type of structure is led to time consuming and unreliable system. For analysis, one of the fundamental difficulties in real-time system is how to be bounded the time behavior of the system. When a distributed control network controls the robot, with a central computing hub that sets the goals for the robot, processes the sensor information and provides coordination targets for the joints. If the distributed system supposed to be connected to a control network, the joints have their own control processors that act in groups to maintain global stability, while also operating individually to provide local motor control. We try to analyze the architecture of network-based humanoid robot's leg part and deal with its application using the CAN(Controller Area Network) protocol.

• Journal of Acupuncture Research
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• v.37 no.2
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• pp.128-135
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• 2020

Background: Classical acupuncture is being used in the treatment of rheumatoid arthritis (RA). To explore the biological response to acupuncture, a network-based analysis was performed on gene expression data collected from an animal model of RA treated with acupuncture. Methods: Gene expression data were obtained from published microarray studies on blood samples from rats with collagen induced arthritis (CIA) and non-CIA rats, both treated with manual acupuncture. The weighted gene co-expression network analysis was performed to identify gene clusters expressed in association with acupuncture treatment time and RA status. Gene ontology and pathway analyses were applied for functional annotation and network visualization. Results: A cluster of 347 genes were identified that differentially downregulated expression in association with acupuncture treatment over time; specifically in rats with CIA with module-RA correlation at 1 hour after acupuncture (-0.27; p < 0.001) and at 34 days after acupuncture (-0.33; p < 0.001). Functional annotation showed highly significant enrichment of porphyrin-containing compound biosynthetic processes (p < 0.001). The network-based analysis also identified a module of 140 genes differentially expressed between CIA and non-CIA in rats (p < 0.001). This cluster of genes was enriched for antigen processing and presentation of exogenous peptide antigen (p < 0.001). Other functional gene clusters previously reported in earlier studies were also observed. Conclusion: The identified gene expression networks and their hub-genes could help with the understanding of mechanisms involved in the pathogenesis of RA, as well understanding the effects of acupuncture treatment of RA.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.165-171
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• 2006

The appearance of over 10,000 TEU containerships (so called Mega-containerships) is determined. In order to operate these ships effectively, the number of these calling ports will diminish, and then feeder ships will transport cargoes from the hub-ports where mega-containerships call to the destination ports. In the hub-ports, handling containers for mega-containerships become huger, thus it is important for terminals to deal with cargo handling as soon as possible. However, the present terminal layout might have the limitation of maximum throughput per time unit. And then the transit time at the ports become longer. Therefore, we investigate the effect on some different terminal layouts with new alternatives. Actually, we discuss the ship-to-berth allocation at some adjacent berths for mega-containerships on three types of terminal layouts. First one is the conventional type consisted by some linear berths, most container terminals in the world are normally this type. Second one is the indented type consisted by linear berths and indented berths which we can handle from both sides of mega-containership simultaneously. Third one is the floating type consisted by linear berths and the floating berth. On this type, mega-containerships can moor between linear and floating berths. The merits of this type are that we can also handle from both sides of mega-containerships simultaneously, and ships can go through between linear berth and floating berths. Thus it is easier for ships to moor and leave berths. Under such assumptions, we examine the numerical experiments. In most cases, the total service times on the indented type are the longest among three types, these on the floating type are the next longer. Those reasons are that these layouts have the differences of berth occupancy obtained by the time and space axes, and whether the precedence constraints of ship service order needs or not.

• Journal of Navigation and Port Research
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• v.30 no.1 s.107
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• pp.53-59
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• 2006

Recently, 8,000TEU class containerships has started operating the shipping service and the mega-containership of over 10,000TEU is on planning. A unit cost in relation to shipping service is decreased by the bigger ship based on the economy of scale. Most of the previous studies have been performed and focused on the total operation cost from mega port to mega port. However, the purpose of this paper is to estimate economic efficiency of selected hub ports from point of view of total cost such as service cost(or operation cost), port charge and feeder cost, etc. First, the service-network of mega containerships is based on data of a domestic shipping company operated main line and economic analysis of individual scenarios on the cost and traffic when 10,000TEU mega containerships offer the services. The three scenarios presented in this paper set up the hub ports which are the port of Busan, Shanghai and Yokohama The results show that port of Busan is economically the most efficient one among others.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.582-591
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• 2015

Late-Koryeo people networks were constructed from four different history books that were written by various historic aspects in the period from king Kongmin to the final king of the Koryeo, Kongyang. All networks constructed in this study show scale free network properties as if most social networks do. Tajo-sillok preface is one of subjectively written history book that described personal history of the Lee Seong-gye and his ancestors. It is confirmed that the book is one of the most biased-written history books through network study. Jeong Do-jeon known as a Chosun dynasty projector is not greatly contributed for founding of a Chosun dynasty in network study and various historical documents as well. In this network study, we provide objective historical information in the historical situations of the late-Koryeo and during establishment procedure of Chosun dynasty. Hub nodes in network is denoted highly linked nodes, called degree. Stress centrality is a unit to measure positional importancy in the network. If we employ two factors, degree and stress centrality to determine hub node, it represents high connectivity and importancy as well. As comparing values of the degree and stress centrality, we elucidate more objective historical facts from late-Koryeo situations in this study. If we further develop and employ a new algorithm that is considered both degree and stress centrality, it is a very useful tool for determining hub node.

• Land and Housing Review
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• v.15 no.1
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• pp.135-146
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• 2024

This study predicts the means sharing ratio of the urban air transportation (UAM) when the VertiHub of the UAM in the southern western part is built at Songjeong Station in Gwanju. Based on Monte Carlo simulation of the utility function and means selection logit model for each means of transportation, our findings indicate an average mode share of 0.95%, with a variability range from 0.07% to 4.7%. Moreover, 95% of the simulation outcomes fall below a 2.02% mode share. Sensitivity analysis, conducted via Tornado Plot, highlights that the mode share is principally influenced by factors such as the unit fare, cost parameter, basic fare, and the time required for takeoff and landing. Notably, a negative correlation exists for unit fare, basic fare, and takeoff and landing time, suggesting the necessity of setting an appropriate level of fair to enhance UAM utilization.

• Journal of Korean Physical Therapy Science
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• v.6 no.3
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• pp.25-40
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• 1999

The hub of weight bearing in the human body for both static and dynamic activities is the lumbopelvic region. It is a key region of extraordinary stability, since the trunk and ground forces converage in this region. The two sacroiliac joints form an integral part of this lumbopelvic unit. Considerable effort has been expended to study and quantify the normal range of movement of the sacroiliac joints Mitchell suggests that the ilium rotates in a posterior direction at heel strike and progresses in an anterior direction as the individual passes through the stance phase. The overall key appears to lie in determining the weight-bearing pattern of the sacroiliac (lumbopelvic) region from above and below that results in the familiar pain of sacroiliac dysfunction, assessing the status of the injured tissues, and intervening with the proper treatment protocols that maximize the body's healing processes. The purpose of this chapter is to provide a comprehensive overview of the sacroiliac joint's tissues and biomechanics, as well as concepts of evaluation and treatment. This overview is aimed at assisting the clinician in identifying the forces that are potentially destructive to the lumbopelvic tissues.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.131-143
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• 1996

In this paper, we propose the improved structure of fully interconnected ATM Switch to develop the small sized switch element and represent practical implementation of switch network. As the part II of the full study about structure and implementation of fully interconnected ATM Switch, this paper especially describes the implementation of an ATM switching element with 8 input port and 8 output port at 155 Mbits/sec each. The single board switching element is used as a basic switching block in a small sized ATm switch for ATM LAN Hub and customer access node. This switch has dedicated bus in 12 bit width(8 bit data + 4 bit control signal) at each input and output port, bit addressing and cell filtering scheme. In this paper, we propose a practical switch architecture with fully interconnected buses to implement a small-sized switch and to provide multicast function withoutany difficulty. The design of switching element has become feasible using advanced CMOS technology and Embedded Gate Array technology. And, we also represent Application Specific Integrated Circuit(ASIC) of Switch Output Multiplexing Unit(SOMU) and 12 layered Printed Circuit Board for interconnection network of switch.