• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.621-625
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• 2012

Conventionally, to measure derailment coefficient of a railway wheel, strain gauges for lateral force measurement are attached to both side of the wheel. But narrow gap between railway wheel and traction motor makes it difficult to attache the strain gauges at the inner side of wheel. In this study, to overcome the hard accessibility to the strain gauge points by narrow gap, a new Wheatstone bridge connection method is presented by attaching all the strain gauges at the outer side of wheel with a new bridge connection. We evaluate the running safety of railway vehicles in accordance with railway safety regulations. The experimental results obtained shows higher sensitivity than conventional methods and the derailment coefficient measurement procedure becomes simpler.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.249-252
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• 2000

An experimental multimodal system combining natural input modes such as speech, lip movement, and gaze is proposed in this paper. It benefits from novel human-compute. interaction (HCI) modalities and from multimodal integration for tackling the problem of the HCI bottleneck. This system allows the user to select menu items on the screen by employing speech recognition, lip reading, and gaze tracking components in parallel. Face tracking is a supplementary component to gaze tracking and lip movement analysis. These key components are reviewed and preliminary results are shown with multimodal integration and user testing on the prototype system. It is noteworthy that the system equipped with gaze tracking and lip reading is very effective in noisy environment, where the speech recognition rate is low, moreover, not stable. Our long term interest is to build a user interface embedded in a commercial car navigation system (CNS).

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.481-486
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• 2001

To increase the production efficiency in dairy industry, proper artificial insemination is the most important operation. For the successful artificial insemination, accurate estrus detection is required. The Korean dairy farmers usually depended on visual observation for estrus detection of cows. Mounting behaviour is one of major inidications observed when cows are at an estrus. A mounting activity detection system for cows using radiotelemetry was developed. This system included a transmitter with a pressure switch, a receiver, a serial communication interface, a personal computer and a computer software. All components and a whole system were tested both in a laboratory and in a farm. The results of this study are as follows: 1. All components including transmitter, receiver and serial interface were operated according to the design specification. 2. A whole system tested with simulated mounting activity of 400 times showed 100% of success rate. 3. In the farm test for 4 days with three cows expecting estrus, one cows experiencing mounting activities showed correct response with this system. However two cows did not show mounting activities because of weak estrus and cold weather during the testing period.

• Journal of The Korean Astronomical Society
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• v.52 no.5
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• pp.207-216
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• 2019

In this paper we introduce a software package, the Very long baseline interferometry Network SIMulator (VNSIM), which provides an integrated platform assisting radio astronomers to design Very Long Baseline Interferometry (VLBI) experiments and evaluate the network performance, with a user-friendly interface. Though VNSIM is primarily motivated by the East Asia VLBI Network, it can also be used for other VLBI networks and generic interferometers. The software package not only integrates the functionality of plotting (u, v) coverage, scheduling the observation, and displaying the dirty and CLEAN images, but also adds new features including sensitivity calculations for a given VLBI network. VNSIM provides flexible interactions on both command line and graphical user interface and offers friendly support for log reports and database management. Multi-processing acceleration is also supported, enabling users to handle large survey data. To facilitate future developments and updates, all simulation functions are encapsulated in separate Python modules, allowing independent invoking and testing. In order to verify the performance of VNSIM, we performed simulations and compared the results with other simulation tools, showing good agreement.

• Korean Journal of Metals and Materials
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• v.49 no.11
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• pp.910-915
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• 2011

The microstructures and mechanical properties of roll-bonded STS439/Al1050/STS304 clad materials were investigated after an annealing process at various temperatures. Interfacial layer was developed at the STS439/Al1050 and Al1050/STS304 interfaces at $550^{\circ}C$. STS439/Al1050/STS304 clad metals fractured suddenly in a single step and the fracture decreased with increasing annealing temperatures at $450^{\circ}C$. After annealing at $550^{\circ}C$, samples fractured in three steps with each layer fracturing independently. Interfacial layers formed at $550^{\circ}C$ with a high Vickers microhardness were found to be brittle. During tensile testing, periodic parallel cracks were observed at the interfacial reaction layer. Observed micro-void between Al1050 and the interfacial layer was found to weaken the Al1050/reaction layer interface, leading to the total separation between Al1050 and the reaction layer.

• Journal of Information Processing Systems
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• v.19 no.2
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• pp.219-231
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• 2023

Intelligent applications are crucial for increasing the popularity of shared urban electric bicycles (EBs). Building an application platform architectural system that can satisfy independent user operations is critical for increasing the intelligent usage of shared EBs. Consequently, we collected online reviews of shared EB applications, conducted semantic processing and sentiment analysis, and refined the positive and negative review data for each function. The positive and negative review indices of each function were calculated using the formulae for positive and negative review indices of product functions, thereby determining the functions that need to be improved. Each function of the Shared EB application was improved according to its business process. The main contributions of this study are to build a user requirement architecture system for the Shared EB application with five dimensions and 22 functions using the Delphi method to design the user interface (UI) of this application based on user satisfaction evaluation results; to create a high-fidelity dynamic interaction prototype and compare user satisfaction before and after improving the Shared EB application functions. The testing results indicate that the changes in the UI significantly improve the user experience satisfaction of the urban Shared EB application, with the positive experience index increasing by 69.21% and the negative experience index decreasing by 75.85% overall. This information can be directly used by relevant companies to improve the functions of the Shared EB application.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.99-107
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• 2006

Magnetic nondestructive testing is very useful far detecting a crack on the surface or near of the surface of the ferromagnetic materials. The distribution of the magnetic flux leakage (DMFL) on a specimen has to be obtained quantitatively to evaluate the crack. The magnetic camera is proposed to obtain the DMFL at the large lift-off. The magnetic camera consists of a magnetic source, magnetic lens, analog to digital converters (ADCs), interface, and computer. The magnetic leakage fields or the distorted magnetic fields from the object, which are concentrated on the magnetic lens, are converted to analog electrical signals tv arrayed small magnetic sensors. These analog signals are converted to digital signals by the ADCs, and are stored, imaged, and processed by the interface and computer. However the magnetic camera has limitations with respect to converting and switching speed, full range and resolution, direct memory access (DMA), temporary storage speed and volume because common ADCs were used. Improved techniques, such as those that introduce the operational amplifier (OP-Amp), amplify the signal, reduce the connection line, and use the low pass filter (LPF) to increase the signal to noise ratio are necessary. This paper proposes the exclusive embedded ADC including OP-Amp, LPF, microprocessor and DMA circuit for the magnetic camera to satisfy the conditions mentioned above.

• Journal of the HCI Society of Korea
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• v.7 no.2
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• pp.49-56
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• 2012

The camera-based mobile applications such as color, pattern and object reading can improve the living quality of blind people. However currently available camera-based applications are uncomfortable for the blind, since these applications do not reflect accessibility requirements of the blind especially on touch screen. We investigated accessibility requirements about rapidly growing camera-based mobile applications on touch screen devices for the blind. In order to identify accessibility requirements, we conducted a usability testing for color reading applications with three different types of interfaces on Android OS. The results of the usability testing were as follows: (1) users preferred short depth of menu hierarchy, (2) the initial audio help was more useful than just-in-time help, (3) users needed both manual and automatic camera shooting modes although they preferred manual to automatic mode, (4) users wanted the OS supported screen reader function to be turned off during the color reading application was running, and (5) users required tactile feedback to identify touch screen boundary. We designed a new user interface for blind people by applying the identified accessibility requirements. From a usability testing of the new user interface with 10 blind people, we showed that the identified accessibility requirements were very useful accessibility guidelines for camera-based mobile applications.

• Archives of design research
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• v.16 no.2
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• pp.161-170
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• 2003

This study aims to understanding the effects of culture on websites with emphasis on the website structure and navigation. The website is inherently‘cultural’because anyone around the world can access to website if he or she is equipped with appropriate equipment. For the importance of cultural role in website, various researches have been conducted to understand the relationship between culture and website. However they tended to focus mainly on phenomenal matters such as color, layout, icon etc. There have been not so many thorough attempts to causal relationships between website and‘thick culture’in depth. The study conducted cross-cultural usability testing of websites between Korea and America. At first, representative I-commerce websites of Korea and America were selected and they were analyzed by the selected frameworks such as layout, display type, element type, and the relationship with homepage and sub-page navigation. The results were used to construct typical prototypes of website for Korea and America for experiment. Two websites were used for cross-cultural usability testing though specially-developed remote testing. 20 users from each country participated in the usability testing. The result shows that Korean users peformed better usability testing for Korean style structure of website while American counterparts showed better performances in American style of websites. Other various significant findings were revealed.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.1-10
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• 2011

As requirements of embedded system get complicated, the tool for analyzing the reliability of embedded software is being needed. A probabilistic modeling is used as the way of analyzing the reliability of a software and to apply it to embedded software controlling multiple devices. So, it is necessary to specialize that to embedded software. Also, existing reliability analyzers should measure the transition probability of each condition in different ways and doesn't consider reusing the model once used. In this paper, we suggest a reliability analyzer for embedded software using embedded software Markov chin model and a unit testing tool. Embedded software Markov chain model is model specializing Markov chain model which is used for analyzing reliability to an embedded software. And a unit testing tool has host-target structure which is appropriate to development environment of embedded software. This tool can analyze the reliability more easily than existing tool by automatically measuring the transition probability between units for analyzing reliability from the result of unit testing. It can also directly apply the test result updated by unit testing tool by representing software model as a XML oriented document and has the advantage that many developers can access easily using the web oriented interface and SVN store. In this paper, we show reliability analyzing of a example by so doing show usefulness of reliability analyzer.