Abstract: In Korea, elements that decide the quality of residential environment are not only diverse, but show deviation as well. However, people do not consider these elements and instead, they try to settle the uniformed style of residential environment, which focuses on the construction development of apartment housing and business based plans. Recently, block-unit redevelopment is becoming the standout alternative plan of standardize redevelopment projects, but constructions become inefficient because of indefinite planning criteria.
In conclusion, the following research is about analyzing and categorizing the development method and legal ground of redevelopment project district and plan determinant and applicable standard; the purpose of this study is to become a basis in compatible analysis of planning standards that will happen in the future.
Abstract: This study is about the orbital TIG welding robot system which travels on the guide rail installed on the pipe, and welds and tracks the pipe seam using the LVS (Laser Vision Sensor) joint profile data. The orbital welding robot system consists of the robot, welder, controller, and LVS. Moreover we can define the relationship between welding travel speed and wire feed speed, and we can make the linear equation using the maximum and minimum amount of weld metal. Using the linear equation we can determine the welding travel speed and the wire feed speed accurately corresponding to the area of weld captured by LVS. We applied this orbital TIG welding robot system to the stainless steel or duplex pipe on DSME (Daewoo Shipbuilding and Marine Engineering Co. Ltd.,) shipyard and the result of radiographic test is almost perfect. (Defect rate: 0.033%).
Abstract: This paper is about middleware which enables group-user applications on mobile devices in physical proximity to interact with other devices without intervention of a central server. Requirements of the middleware are identified from service usage scenarios, and the functional architecture of the middleware is specified. These requirements include Group Management, Synchronization, and Resource Management. Group Management needs to provide various capabilities to such applications with respect to managing multiple users (e.g., creation of groups, discovery of group or individual users, member join/leave, election of a group manager and service-group association) using D2D communication technology. We designed the middleware for the above requirements on the Android platform.
Abstract: The composite pavement system considered in this paper is composed of a functional surface layer, a fiber reinforced asphalt middle layer and a fiber reinforced lean concrete base layer. The mix design of the fiber reinforced lean concrete corresponds to the mix composition of conventional lean concrete but reinforced by fibers. The quasi-absence of research on the durability or long-term performances (fatigue, creep, etc.) of such mix design stresses the necessity to evaluate experimentally the long-term characteristics of this layer composition. This study tests the creep characteristics as one of the long-term characteristics of the fiber reinforced lean concrete layer for composite pavement using a new creep device. The test results reveal that the lean concrete mixed with fiber reinforcement and fly ash develops smaller creep than the conventional lean concrete. The results of the application of the CEB-FIP prediction equation indicate that a modified creep prediction equation should be developed to fit with the new mix design of the layer.
Abstract: This study intends to improve the bond performance of the polypropylene fiber used as reinforcing fiber for concrete by changing its shape into double crimped type through the enhancement its fabrication process. The bond performance of such double crimped fiber is evaluated by applying the JCI SF-8 (dog-bone shape) testing method. The test results reveal that the double crimped fiber develops bond performance improved by more than 19% compared to the conventional crimped type fiber.
Abstract: This paper proposes a method to recognize the tip of a finger and space touch hand gesture using an infrared camera in a smart device environment. The proposed method estimates the tip of a finger with a curvature-based ellipse fitting algorithm, and verifies that the estimated object is indeed a finger with an ellipse fitting rectangular area. The feature extracted from the verified finger tip is used to implement the movement of a mouse and clicking gesture. The proposed algorithm was implemented with an actual smart device to test the proposed method. Empirical parameters were obtained from the keypad software and an image analysis tool for the performance optimization, and a comparative analysis with conventional research showed improved performance with the proposed method.
Abstract: The purpose of the research is to investigate the energetic feature of the backpack load on soldier’s gait with variation of the trunk flexion angle. It is believed that the trunk flexion variation of the loaded gait may cause a significant difference in the energy cost which is often in practice in daily life. To this end, seven healthy Korea military personnel participated in the experiment and are tested under three different walking postures comprised of the small, natural and large trunk flexion. There are around 5 degree differences of waist angle between each trunk flexion. The ground reaction forces were collected from the force plates and motion kinematic data are measured by the motion capture system. Based on these data, the impulses, momentums and mechanical works done on the center of body mass (COM) during the double support phase were computed. The result shows that the push-off and heel strike impulse are not relevant to the trunk flexion change, however the mechanical work by the push-off and heel strike were changed by the trunk flexion variation. It is because the vertical velocity of the COM during the double support phase is increased significantly with an increase in the trunk flexion. Therefore, we can know that the gait efficiency of the loaded gait depends on the trunk flexion angle. Also, even though the gravitational impulse and pre-collision momentum are changed by the trunk flexion variation, the after-collision momentum is almost constant regardless of the trunk flexion variation.
Abstract: Brushless DC motor with high torque density and slim
topology for easy loading for robot system is proposed and
manufactured. Electromagnetic design is executed by equivalent
magnetic circuit model and numerical analysis. Manufactured motor is
tested and verified characteristics comparing with conventional BLDC
motor.
Abstract: In this study, we developed an algorithm for detecting
seam cracks in a steel plate. Seam cracks are generated in the edge
region of a steel plate. We used the Gabor filter and an adaptive double
threshold method to detect them. To reduce the number of pseudo
defects, features based on the shape of seam cracks were used. To
evaluate the performance of the proposed algorithm, we tested 989
images with seam cracks and 9470 defect-free images. Experimental
results show that the proposed algorithm is suitable for detecting seam
cracks. However, it should be improved to increase the true positive
rate.
Abstract: In recent years, it has been proposed security
architecture for sensor network.[2][4]. One of these, TinySec by Chris
Kalof, Naveen Sastry, David Wagner had proposed Link layer security
architecture, considering some problems of sensor network. (i.e :
energy, bandwidth, computation capability,etc). The TinySec employs
CBC_mode of encryption and CBC-MAC for authentication based on
SkipJack Block Cipher. Currently, This TinySec is incorporated in the
TinyOS for sensor network security.
This paper introduces TinyHash based on general hash algorithm.
TinyHash is the module in order to replace parts of authentication and
integrity in the TinySec. it implies that apply hash algorithm on
TinySec architecture. For compatibility about TinySec, Components
in TinyHash is constructed as similar structure of TinySec. And
TinyHash implements the HMAC component for authentication and
the Digest component for integrity of messages. Additionally, we
define the some interfaces for service associated with hash algorithm.
Abstract: Due to environmental concerns, the recent regulation on automobile fuel economy has been strengthened. The market demand for efficient vehicles is growing and automakers to improve engine fuel efficiency in the industry have been paying a lot of effort. To improve the fuel efficiency, it is necessary to reduce losses or to improve combustion efficiency of the engine. VVA (Variable Valve Actuation) technology enhances the engine's intake air flow, reduce pumping losses and mechanical friction losses. And also, VVA technology is the engine's low speed and high speed operation to implement each of appropriate valve lift. It improves the performance of engine in the entire operating range. This paper presents a design procedure of DC motor and drive for VVA system and shows the validity of the design result by experimental result with prototype.
Abstract: A SCADA (Supervisory Control And Data
Acquisition) system is an industrial control and monitoring system for
national infrastructures. The SCADA systems were used in a closed
environment without considering about security functionality in the
past. As communication technology develops, they try to connect the
SCADA systems to an open network. Therefore, the security of the
SCADA systems has been an issue. The study of key management for
SCADA system also has been performed. However, existing key
management schemes for SCADA system such as SKE(Key
establishment for SCADA systems) and SKMA(Key management
scheme for SCADA systems) cannot support broadcasting
communication. To solve this problem, an Advanced Key
Management Architecture for Secure SCADA Communication has
been proposed by Choi et al.. Choi et al.-s scheme also has a problem
that it requires lots of computational cost for multicasting
communication. In this paper, we propose an enhanced scheme which
improving computational cost for multicasting communication with
considering the number of keys to be stored in a low power
communication device (RTU).
Abstract: Human heart valves diseased by congenital heart
defects, rheumatic fever, bacterial infection, cancer may cause stenosis
or insufficiency in the valves. Treatment may be with medication but
often involves valve repair or replacement (insertion of an artificial
heart valve). Bileaflet mechanical heart valves (BMHVs) are widely
implanted to replace the diseased heart valves, but still suffer from
complications such as hemolysis, platelet activation, tissue
overgrowth and device failure. These complications are closely related
to both flow characteristics through the valves and leaflet dynamics. In
this study, the physiological flow interacting with the moving leaflets
in a bileaflet mechanical heart valve (BMHV) is simulated with a
strongly coupled implicit fluid-structure interaction (FSI) method
which is newly organized based on the Arbitrary-Lagrangian-Eulerian
(ALE) approach and the dynamic mesh method (remeshing) of
FLUENT. The simulated results are in good agreement with previous
experimental studies. This study shows the applicability of the present
FSI model to the complicated physics interacting between fluid flow
and moving boundary.
Abstract: Recently in the field of bridges that are newly built or
repaired, fast construction is required more than ever. For these
reasons, precast prefabricated bridge that enables rapid construction is
actively discussed and studied today. In South Korea, it is called
modular bridge. Cross beam is an integral component of modular
bridge. It functions for load distribution, reduction of bending
moment, resistance of horizontal strength on lateral upper structure. In
this study, the structural characteristics of domestic and foreign cross
beam types were compared. Based on this, alternative cross beam
connection types suitable for modular bridge were selected. And
bulb-T girder specimens were fabricated with each type of connection.
The behavior of each specimen was analyzed under static loading, and
cross beam connection type which is expected to be best suited to
modular bridge proposed.
Abstract: Single crystals of Magnesium alloys such as pure Mg,
Mg-1Zn-0.5Y, Mg-0.1Y, and Mg-0.1Ce alloys were successfully
fabricated in this study by employing the modified Bridgman method.
To determine the exact orientation of crystals, pole figure
measurement using X-ray diffraction were carried out on each single
crystal. Hardness and compression tests were conducted followed by
subsequent recrysatllization annealing. Recrystallization kinetics of
Mg alloy single crystals has been investigated. Fabricated single
crystals were cut into rectangular shaped specimen and solution
treated at 400oC for 24 hrs, and then deformed in compression mode
by 30% reduction. Annealing treatment for recrystallization has been
conducted on these cold-rolled plates at temperatures of 300oC for
various times from 1 to 20 mins. The microstructure observation and
hardness measurement conducted on the recrystallized specimens
revealed that static recrystallization of ternary alloy single crystal was
very slow, while recrystallization behavior of binary alloy single
crystals appeared to be very fast.
Abstract: This paper presents an automated inspection algorithm
for a thick plate. Thick plates typically have various types of surface
defects, such as scabs, scratches, and roller marks. These defects have
individual characteristics including brightness and shape. Therefore, it
is not simple to detect all the defects. In order to solve these problems
and to detect defects more effectively, we propose a dual light
switching lighting method and a defect detection algorithm based on
Gabor filters.
Abstract: The aim of this paper is to confirm the effect of key
design parameters, the punch radius and punch angle, on rupture of the
expansion tube using a finite element analysis with a ductile damage
model. The results of the finite element analysis indicated that the
expansion ratio of the tube was mainly affected by the radius of the
punch. However, the rupture was more affected by the punch angle
than the radius of the punch. The existence of a specific punch angle,
at which rupture did not occur, even if the radius of the punch was
increased, was found.
Abstract: Bio-electrical responses obtained from freshwater
sediments by employing microbial fuel cell (MFC) technology were
investigated in this experimental study. During the electricity
generation, organic matter in the sediment was microbially oxidized
under anaerobic conditions with an electrode serving as a terminal
electron acceptor. It was found that the sediment organic matter
(SOM) associated with electrochemically-active electrodes became
more humified, aromatic, and polydispersed, and had a higher average
molecular weight, together with the decrease in the quantity of SOM.
The alteration of characteristics of the SOM was analogous to that
commonly observed in the early stage of SOM diagenetic process (i.e.,
humification). These findings including an elevation of the sediment
redox potential present a possibility of the MFC technology as a new
soil/sediment remediation technique based on its potential benefits:
non-destructive electricity generation and bioremediation.
Abstract: This paper suggests a new Affine Projection (AP) algorithm with variable data-reuse factor using the condition number as a decision factor. To reduce computational burden, we adopt a recently reported technique which estimates the condition number of an input data matrix. Several simulations show that the new algorithm has better performance than that of the conventional AP algorithm.
Abstract: The protection issues in distribution systems with open and closed-loop are studied, and a generalized protection setting scheme based on the traditional over current protection theories is proposed to meet the new requirements. The setting method is expected to be easier realized using computer program, so that the on-line adaptive setting for coordination in distribution system can be implemented. An automatic setting program is created and several cases are taken into practice. The setting results are verified by the coordination curves of the protective devices which are plotted using MATLAB.