• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.164-175
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• 2019

Installation of digital tachograph, black box, and ADAS have been enforced to commercial vehicles for preventing violent driving and accidents by the Traffic Safety Act in Korea. Nevertheless, the damage caused by road hazards has increased 1.5 times in 2016 compared to 2013. So, developing new technologies that can identify road hazard using the sensors installed in commercial vehicles are conducting by the Ministry of Land, Infrastructure and Transport. As a part of the technologies, this research analyze the error range of GPS installed in commercial vehicles that vary according to the driving speed. As a result, the average error was 9.72m at the driving speed of 100km/h, and the error was 2.1 times larger than the average error of 4.69m at the driving speed of 40km/h. The event point proper integration/separation range(m) was analyzed to be 20m with a recognition rate of 90% or more at the same point regardless of driving speed. The results of this research can be used as basic data for improving the accuracy of location-based data would be collected using commercial vehicles.

• Journal of the HCI Society of Korea
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• v.1 no.2
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• pp.1-8
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• 2006

This paper presents a development of new haptic API (Application Programming Interface) that is called K-$Touch^{TM}$ haptic API. It is designed in order to allow users to interact with objects by kinesthetic and tactile modalities through haptic interfaces. The K-$Touch^{TM}$ API would serve two different types of users: high level programmers who need an easy to use haptic API for creating haptic applications and researchers in the haptic filed who need to experiment or develop with new devices and new algorithms while not wanting to re-write all the required code from scratch. Since the graphic hardware based kinesthetic rendering algorithm implemented in the K-$Touch^{TM}$ API is different from any other conventional kinesthetic algorithms, this API can provide users with haptic interaction for various data representations such as 2D, 2.5D depth(height field), 3D polygon, and volume data. In addition, this API supports kinesthetic and tactile interaction simultaneously in order to allow users with realistic haptic interaction. With a wide range of applicative characteristics, therefore, it is expected that the proposed K-$Touch^{TM}$ haptic API will assists to have deeper recognition of the environments, and enhance a sense of immersion in environments. Moreover, it will be useful development toolkit to investigate new devices and algorithms in the haptic research field.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.997-1006
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• 2010

For manufacturing modern cars, so-called multi-materials, such as aluminum alloy with high-strength steels, are used. For obtaining such materials, a new joining method is required to achieve the multi-material design. Mechanical clinching is one of joining methods used to join the dissimilar materials. The objective of this study is to investigate the characteristics of mechanical clinching of Al5052 alloy to high-strength steels (SPFC440, 590, 780). Using FE-analysis and clinching experiment, the joinability of Al5052 alloy to high-strength steel is evaluated by geometrical shape of mechanical clinched joint, such as neck-thickness and undercut. Further, the joint strength is evaluated by performing a single-lap shear test. The upper high-strength steel SPFC780 was not clinched because of the necking of the upper sheet. The joint strength increased with increasing strength of the upper sheet. For the lower high-strength steel sheet, the joinability and joint strength decreased with increasing strength of the lower sheet.

• Clean Technology
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• v.13 no.4
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• pp.293-299
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• 2007

Direct coating of catalyst layer on the $Nafion^{(R)}$ membrane has been optimized in the process of fabrication of membrane electrode assembly (MEA) to enhance the performance of direct methanol fuel cell (DMFC). In this method, the contact resistance at the interface of the catalyst layer and the membrane was found to be low. The effect of catalyst loading, thickness of membrane and the gas diffusion layer (GDL) with or without the presence of micro-porous layer (MPL) on the performance of the MEA was also investigated. The MEA fabricated by the above-mentioned method exhibited a performance of $147\;mW/cm^2$ and $100\;mW/cm^2$ at $80^{\circ}C$ and $60^{\circ}C$, respectively, with the catalysts loading of $4\;mg/cm^2$.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.332-347
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• 2017

Analysis of the interaction between the automated vehicles and manual vehicles is very important in analyzing the performance of automated cooperative driving environments. In particular, the automated vehicle platooning can affect the driving behavior of adjacent manual vehicles. The purpose of this study is to analyze the lane change behavior of the manual vehicles in automated vehicle platonning environment and to conduct the experiment and questionnaire surveys in three stages. In the first stage, a video questionnaire survey was conducted, and responsive behaviors of manual vehicles were investigated. In second stage, the driving simulator experiments were conducted to investigate the lane change behaviors of in automated vehicle platonning environments. To analyze the lane change behavior of the manual vehicles, lane change durations and acceleration noise, which are indicators of traffic flow stability, were used. The driving behavior of manual vehicles were compared across different market penetration rates (MPR) of automated vehicles and human factors. Lastly, NASA-TLX (NASA Task Load Index) was used to evaluate the workload of the manual vehicle drivers. As a result of the analysis, it was identified that manual vehicle drivers had psychological burdens while driving in automated vehicle platonning environments. Lane change durations were longer when the MPR of the automated vehicles increased, and acceleration noise were increased in the case of 30-40 years old or female drivers. The results from this study can be used as a fundamental for more realistic traffic simulations reflecting the interaction between the automated vehicles and manual vehicles. It is also expected to effectively support the establishment of valuable transportation management strategy in automated vehicle environments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.147-153
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• 2018

PLGA microcapsule particles encapsulating BSA aqueous solutions were prepared using a water-in-oil-in-water emulsion method. The morphology, particle size, BSA encapsulating efficiency, and in-vitro release test were also studied using the microcapsule particles. In the outer aqueous phase, an emulsifier, e.g., PVA, was replaced with metal salts for surface solidification. Scanning electron microscopy (SEM) showed that the microcapsule particles had smooth surfaces and were between $1{\mu}m$ and $7{\mu}m$ in size. The microcapsule particle morphology was affected directly by the ratio between the polymer solution and inner aqueous solution, and composition of the outer aqueous solution. The factors also partially affected the BSA encapsulation efficiencies and in-vitro release rates. All the microcapsule particles showed an initial burst release through the in-vitro release test. On the other hand, the particles also showed a relatively long release period. Metal salts could be good choices to replace the emulsifier to solidify the microcapsule particle surfaces.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.639-645
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• 2018

This paper is intended to develop a decision model that can be applied to autonomous vehicles and autonomous mobile vehicles. The developed module has an independent configuration for application in various driving environments and is based on a platform for organically operating them. Each module is studied for decision making on lane changes and for securing safety through reinforcement learning using a deep learning technique. The autonomous mobile moving body operating to change the driving state has a characteristic where the next operation of the mobile body can be determined only if the definition of the speed determination model (according to its functions) and the lane change decision are correctly preceded. Also, if all the moving bodies traveling on a general road are equipped with an autonomous driving function, it is difficult to consider the factors that may occur between each mobile unit from unexpected environmental changes. Considering these factors, we applied the decision model to the platform and studied the lane change decision system for implementation of the platform. We studied the decision model using a modular learning method to reduce system complexity, to reduce the learning time, and to consider model replacement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.739-744
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• 2017

Elastic deformation and fatigue damage can cause the permanent deformation of a kart's frame during turning, affecting the kart's driving performance. A kart's frame does not contain any suspension or differential devices and, therefore, the dynamic behavior caused by torsional deformation when driving along a curve can strongly affect these two kinds of deformations. To analyze the dynamic behavior of a kart along a curved section, the GPS trajectory of the kart is obtained and the torsional stress acting on the kart-frame is measured in real time. The mechanical properties of leisure and racing karts are investigated by analyzing their material properties and conducting a tensile test. The torsional stress concentration and frame distortion are investigated through a stress analysis of the frame on the basis of the obtained results. Leisure and racing karts are tested in each driving condition using driving analysis equipment. The behavior of a kart when being driven along a curved section is investigated through this test. Because load movement occurs owing to centrifugal force when driving along a curve, torsional stress acts on the kart's steel frame. In the case of a leisure kart, the maximum torsional stress derived from the torsional fatigue limit was found to be 230 MPa, and the torsional fatigue limit coefficient was 0.65 when driving at a speed of 40 km/h. Furthermore, the driving elements during the cornering of a kart were measured based on an actual auto-test after installing a driving measurement system, and the driving behavior of the kart was analyzed by measuring its vertical displacement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.283-290
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• 2020

In this study, a floater was developed for a frame-type solar power plant. The floater supports the frame and the solar panels. A finite element analysis was performed to design its shape and thickness, and the floater was manufactured by a rotational molding method using linear low-density polyethylene. It was found that the floater did not cause collapse and it maintained its stiffness even at 4 times the maximum load of 322.7 kgf. To perform a long-term compression test, a weight-type load application device that uses gravity was designed and manufactured. The amount of compressive deformation was measured for 7 days, and a long-term deformation equation was obtained. Even under small loads, continuous deformation was observed. However, the 10-year deformation amount for a constant load of 100 kgf was predicted to be small at about 4.64 mm. As a result, it was found that the developed floater could be used in a solar power plant on a body of water.

• Journal of Korean Library and Information Science Society
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• v.43 no.3
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• pp.5-26
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• 2012

This study is to find the new method for authority control in Korea by surveying status of authority control in university libraries and by analyzing international conceptual model of authority control and VIAF. 2 kinds of survey were done: one is for libraries having authority records and the other is for libraries not having authority records. In survey result, libraries that have authority records want to sustain their own forms of authorized access points and libraries that have no authority records want the rules related to authority and the national cooperative authority control system to be constructed. Based on ICP 2009, FRAD conceptual model, VIAF and this survey result, new authority control is to respect the diversity of forms of the authorized access points. New authority control is to permit authority records that reflect provision for linguistic or cultural environments of each library, confirming to the national cataloging code. Therefore, authorized access points will be displayed according to user preferred forms. For this new authority control, it is needed to make national authority rule, to build the authority records according to library's own rules, and to construct the cooperative authority control system. Also for user preferred authority control, it is needed to describe detailed elements for authority control and relation data between authorized access points, between authorized access points and variant forms. This study could contribute to suggest new authority control that could accept all kinds of authorized access points preferred by nation, libraries, and users.