A reduction of motor performance due to brain disorders can be screened by evaluating force tracking capabilities (FTCs). Existing studies have examined FTCs mainly using simple sinusoidal waves, of which repeated profiles have a critical limitation due to a learning effect in force tracking. The present study examined the effects of personal factors (age and gender) and sinusoidal wave factors (central force and complexity) on FTCs of healthy adults using composite sinusoidal wave profiles (CSWPs). FTCs were measured using Finger $Touch^{TM}$ for 30 seconds and quantified in terms of time within the target range (TWR, accuracy measure) and relative RMSE (RRMSE, variability measure). A total of 90 healthy adults in 20s to 70s with the equal gender ratio participated in the experiment consisting of combinations of 2 central force levels (6 N and 10 N) and 2 complexity levels (approximate entropy, ApEn = 0.03 and 0.06) of CSWPs. Significantly decreased FTCs (lower TWR and higher RRMSE) were found in aged adults, females, the low central force, and the high complexity. The detailed FTC decrements include a 43% reduced TWR and a 85% increased RRMSE of older adults in 70s as compared to those in 20s, a 17% reduced TWR and a 17% increased RRMSE of female as compared to those of male, a 30% reduced TWR and a 108% increased RRMSE at central force = 6N when compared to those at central force = 10N, and a 19% reduced TWR and a 30% increased RRMSE at ApEn = 0.06 as compared to those at ApEn = 0.03. The characteristics of FTCs for CSWPs can be of use in establishing an assessment protocol of motor performance for screening brain disorders.

With the recent interests with culture technologies, many studies for recommendation systems have been done. In this vein, various music recommendation systems have been developed. However, they have often focused on the technical aspects such as feature extraction and similarity comparison, and have not sufficiently addressed them in user-centered perspectives. For users' high satisfaction with recommended music items, it is necessary to study how the items are connected to the users' actual desires. For this, our study proposes a novel music recommendation method based on serendipity, which means the freshness users feel for their familiar items. The serendipity is measured through the comparison of users' past and recent listening tendencies. We utilize neural networks to apply these tendencies to the recommendation process and to extract the features of music items as MFCCs (Mel-frequency cepstral coefficients). In that the recommendation method is developed based on the characteristics of user behaviors, it is expected that user satisfaction for the recommended items can be actually increased.

This thesis focuses on the 3D interface tab page type and mode of screen that affect the usability of the small screen devices such as smartphone. The experiments examined eight 3D UI designs, combinations of two modes (Portrait, Landscape) of screen, and four types (Vertical data mountain, Horizontal data mountain, Vertical carousel, Horizontal carousel). Twenty-six participants participated in the experiment. The completion time, preference and fun score were measured. The results showed that the vertical data mountain type provide the best performance in terms of the all conditions. The results of this study suggest a practical approach for the 3D UI tab page design for the small screen devices.

In this study, the effective technology readiness assessment (TRA) method for system development project is suggested. We analyze the domestic and foreign TRA practice and derive the new idea to resolve the problems found from the analysis. Domestic and foreign organizations develop and use checklist for the precise TRA, but the checklist has some problems in type of questions and analysis of assessment. TRA method using the original TRL definition or the checklist should be selected depending on the project characteristic. Questions of the checklist should be classified into critical or non-critical according to their importance. Finally, Test and evaluation master plan (TEMP) in system engineering process can provide an obvious criteria to assess technology readiness level (TRL) of critical technology elements (CTE) composing the system.

This paper proposes a new approach to technology valuation, the market-replacement cost approach which integrates the cost-based approach and market-based approach. The proposed approach estimates the market-replacement cost of a target technology using R&D costs of similar R&D projects previously conducted. Similar R&D projects are extracted from project database based on document similarity between project proposals and technology description of the target technology. R&D costs of similar R&D projects are adjusted by mirroring the rate of technological obsolescence and inflation. Market-replacement cost of the technology is then derived by calculating the weighted average of adjusted costs and similarity values of similar R&D projects. A case of "Prevention method and system for the diffusion of mobile malicious code" is presented to illustrate the proposed approach.

This paper proposes a Product Data Management (PDM) system architecture that supports end-user computing for small and medium businesses (SMBs) in Korea to build and maintain efficient and sustainable information systems for their product development. Its open database with relational tables enables existing common application programs such as Microsoft office suites to access product data in PDM systems. In addition, the interactive query processor provided by database management systems helps design engineers to build ad hoc queries in standard SQL database language to response different data requirements during their product development. The PDM architecture with the open database allows design engineers or technical staffs in SMBs to build and maintain their application programs for product development by themselves. To show the feasibility of the proposed architecture, this study implemented a prototype PDM system based on the architecture and database, and represents real-world product data with the implemented PDM system.

The application of radio frequency identification (RFID) sensor-tags in cold chain systems has recently received a great deal of attention. To design cold chain systems with RFID sensor-tags that minimize the initial investment and operational cost while fulfilling the functional and operational requirements, simulation study is one of the preferable and effective approaches. To simulate the possible design configurations, the individual components in a cold chain system can be extracted and implemented as a DEVS (Discrete Event System Specification) model. Based on the proposed DEVS model, a new cold chain simulation model can be efficiently created by simply connecting each DEVS model around the RFID sensor-tag of interest in sequence according to the structure of the cold chain system, and then executed (or simulated) on Java programming environments by the DEVSJAVA simulator. As a result of simulation, some key performance indexes such as reliability, accuracy or timeliness can be calculated and used to choose better components or to compare different system configurations of cold chain systems.

The explosive growth of the world-wide-web and the emergence of e-commerce has led to the development of recommender systems. Recommender systems are personalized information filtering used to identify a set of items that will be of interest to a certain user. This paper reviews recommender systems and presents their pros and cons.

This paper deals with a case study about productivity improvement in medium and small-sized manufacturing factories. It is popular to improve the productivity of lines by shortening the production cycles and assigning multi jobs to workers. We analyze the production lines and improve the productivity in the case study through multi-functional workers and shortened production lines. Based on the case study, we propose some guidelines to improve the productivity of production lines.

The DCF (Dcistributed Coordination Function) and PCF (Point Coordination Function) are the basic MAC (Medium Access Control) protocols of IEEE 802.11 wireless LANs. According to the DCF, each node performs the exponential backoff algorithm before the transmission of its data frame. Each node doubles the backoff waiting time before the transmission of its data frame whenever it detects the transmission collision with other nodes. Therefore, as the number of the active nodes having the data frames to transmit increases, the overall MAC performance of the DCF decreases. On the other hand, according to the PCF, each node is granted the transmission opportunity by which the PCF transmission is possible without the collision with other nodes. Therefore, as the number of the active nodes increases, the MAC performance of the PCF increases, In this paper, considering the tradeoff of MAC performance between the DCF and PCF, a hybrid MAC protocol is proposed to enhance the performance of IEEE 802.11 wireless LANs.