• Journal of the Korean earth science society
• /
• v.25 no.5
• /
• pp.336-347
• /
• 2004

This study investigated the effects of the application of a variety of ICTs cause the effects on self-directed learning capability, creativity and problem-solving ability. In order to achieve the above aim, Web-Based Instructions(WBI) and instructions using CD-ROM Titles for the unit of 'the solar system and the galaxy' were applicated and analyzed which belongs to the area of 'the earth' in the subject 'science' for high school students. Instructions using WBI materials and CD-ROM titles were found to be effective on 'self-conception', 'creativity', 'future inclination', 'self-assessment ability', 'openness' and' initiative' improvement all of which belong to self-directed learning characteristics. They did not, however, show meaningful effect on improving 'learning eagemess' and 'responsibility' improvement. On looking into self-directed learning characteristics according to prerequisite learning levels, both groups and these for instruction using CD-ROM learning materials were found to have no effect on interaction. With respect to problem-solving ability improvement which is characteristic of the instruction using ICTs, WBI proved more fruitful than instruction using CD-ROM titles on improving scholastic achievement level. WBI was effective on 'fluency', 'originality' and 'resistance to premature closure'. It on the other hand, was of no use on 'abstraction of titles' and 'elaborateness' These results came from the following characteristics: WBI came into effect on 'fluency' and 'originality' in the areas of variety and vitality, which are characteristic of WBI. In the area of resistance to premature closure WBI was effective on organizing learning contents owing to the animation of picture materials which are variously presented in the web site. As a result of WBI questionnaire about WBI, an excellent effect on the structure of display, quantity of information, indication and instruction, supplementary study and further study were discussed.

• Journal of Yeungnam Medical Science
• /
• v.20 no.2
• /
• pp.177-186
• /
• 2003

Background: Clinical and radiological results based on fracture types and associated injuries after the treatment of tibial plateau fracture were evaluated for analyzing prognostic factors. Materials and Methods: From June 1997 to June 2002, 50 cases were followed for at least 1 year. Mean age was 47.4 years, and mean follow period was 30.0 months. Fracture classification was performed by the Schatzker method. Clinical and radiological evaluation were performed by the Porter and Rasmussen method. Evaluation was based on degree of reduction and associated injuries, etc. Results: The most common cause of injury was traffic accident (37 cases, 74%), The common fracture types by Schatzker classification were type II (14 cases) and VI (12 cases). Methods of treatment were screw fixation (15 cases), plate and screw (21 cases), external fixator (5 cases), and conservative treatment (9 cases). The most common associated injuries were ipsilateral fibular fracture (18 cases) and MCL (medial collateral ligament) injury (8 cases). Conclusion: Acceptable results after treatment of tibial plateau fracture were obtained from the anatomical reduction group, non-associated injury group, the young age group, and the early ROM (range of motion) beginning group.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2002.10a
• /
• pp.60-63
• /
• 2002

Metal/intermetallic laminated composites have been manufactured by SHS reactions between Ni and Al elemental metal foils. Microstructure showed that the intermetallic volume fraction was 55%, 45%, 35% in the 1:1, 2:1, 4:1 thickness ratio(Ni:Al) specimen and the main phases of the intermetallic were transformed from $Ni_2Al_3$ to NiAl when the thickness ratio was increased. Tensile strength and elongation were increased when the volume fraction of Ni metallic phase was increased. Under assumptions of isostrain condition, the tensile strength of metal/intermetallic laminated composites didn't obey the ROM due to the thermal residual stress and this was confirmed by X-ray residual stress analysis. Fracture toughness results by the SENB test showed R-curves with upward curvature based on LSB condition. Bridging stress based on LSB condition was determined by the curve fitting analysis, In-situ observed microstructure during fracture test showed that the various bridging mechanism such as crack bridging, crack branching and ductile failure of metallic layer were occurred

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.5
• /
• pp.522-526
• /
• 2015

Generally, underwater unmanned vehicle have adopted an inertial navigation system (INS), dead reckoning (DR), acoustic navigation and geophysical navigation techniques as the navigation method because GPS does not work in deep underwater environment. Even if the tactical inertial sensor can provide very detail measurement during long operation time, it is not suitable to use the tactical inertial sensor for small size and low cost UUV because the tactical inertial sensor is expensive and large. One alternative to INS is attitude heading reference system (AHRS) with the micro-machined electro mechanical system (MEMS) inertial sensor because of MEMS inertial sensor's small size and low power requirement. A cost effective and small size attitude heading reference system (AHRS) which incorporates measurements from 3-axis micro-machined electro mechanical system (MEMS) gyroscopes, accelerometers, and 3-axis magnetometers has been developed to provide a complete attitude solution for UUV. The AHRS based MEMS overcome many problems that have inhibited the adoption of inertial system for small UUV such as cost, size and power consumption. Several evaluation experiments were carried out for the validation of the developed AHRS's function and these experiments results are presented. Experiments results prove the fact that the developed MEMS AHRS satisfied the required specification.

• Journal of the Institute of Convergence Signal Processing
• /
• v.8 no.3
• /
• pp.205-210
• /
• 2007

This paper presents a CMOS TIQ flash A/D converter which operates very fast compared to other types of A/D converters due to its parallel architecture. The output resolution of designed A/D converter is 6-bit. In order to reduce the power consumption and chip area of conventional flash A/D converter, TIQ based flash A/D converter is proposed, which uses the advantage of the structure of CMOS transistors. The length and width of transistors of TIQ were determined with HSPICE simulation. To speed up the ultra-high speed flash A/D converter, the Fat Tree Encoder technique is used. The TIQ A/D converter was designed with full custom method. The chip's maximum power consumption was 38.45mW at 1.8V, and the operating speed of simulation was 2.7 GSPS.

• Clinics in Shoulder and Elbow
• /
• v.3 no.1
• /
• pp.26-32
• /
• 2000

Purpose : The aim of this study is the assessment of the clinical outcomes after percutanous pinning of unstable two-parts fracture of surgical neck in humerus. Materials and Methods: This study was based on thirteen cases of non-comminuted unstable surgical neck fracture of humerus among 19 cases, which followed-up more than one year. Follow-up averaged 29 months. We treated with percutaneous pinning techniques and assessed clinical outcomes. Functional evaluation was performed using the standard method of research committee of American Shoulder and Elbow Surgeons(ASES). Results: Last follow-up ROM of shoulder joint were 142 degrees of forward elevation, 57 degrees of external rotation, 72 degrees of external rotation in 90 degrees abduction, and T8 of internal rotation. Pain scale was l(range : 0∼3). ASES scores was 86.2(range : 63.3~98.3). Patient satisfaction based on ASES were excellent in 6 cases, good in 5 cases, fair in 1 case, poor in 1 case. A case of fair result was caused by limitation of motion in shoulder joint and poor case was paraplegia patient after traffic accident. Conclusion : Percutaneous pinning is recommended for non-comminuted unstable fracture of surgical neck in humerus.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.54 no.4
• /
• pp.243-250
• /
• 2005

Test methodology is diversity by devices and the number of test pattern is tremendous because the digital circuit includes TTL and CMOS family ICs as well as high density devices such as ROM and RAM. Accordingly, the quick and effective test strategy is required to enhance the test productivity. This paper proposes the test strategy which is able to be applied efficiently to the diversity devices on the digital circuit board by analyzing the structure and characteristic of the digital device. Especially, this test strategy detects the faulted digital device or the faulted digital circuit on the digital board using SSA(Serial Signature Analysis) technique based on the polynomial division theory The SSA technique identifies the faults by comparing the reminder from good device with reminder from the tested device. At this time, the reminder is obtained by enforcing the data stream obtained from output pins of the tested device on the LFSR(Linear Feedback Shift Register) representing the characteristic equation. Also, the method to obtain the optimal signature analysis circuit is explained by furnishing the short bit input streams to the long bit input streams to the LFSR having 8, 12, 16, 20bit input/output pins and by analyzing the occurring probability of error which is impossible to detect. Finally, the effectiveness of the proposed test strategy is verified by simulating the stuck at 1 errors or stuck at 0 errors for several devices on typical 8051 digital board.

• Korean Journal of Child Studies
• /
• v.31 no.4
• /
• pp.139-157
• /
• 2010

This study investigated the cognitive process of 5-year-old children, with a particular focus on gender, monthly age, and their tendencies towards hyperactivity through the performance of the Cognitive Assessment System (CAS; Das & Naglieri, 1997). The children with tendencies towards hyperactivity were identified based on Conners Teachers' Rating Scale (CTRS). The subjects were 75 five-year-old children in Seoul and surrounding metropolitan areas. Data were analyzed by means of descriptive statistics, an independent sample t-test, Pearson's correlation coefficient, one-way ANOVA, and by K-mean cluster analysis. Our results were as follows : (1) The CAS and CTRS' sub-factors were correlated negatively, except the positive correlation between planning factor and hyperactivity factor. (2) Girls exhibited significantly higher CAS scores in planning & sequential processing than boys. (3) The upper monthly age group (68-71 months) showed significantly higher score in terms of planning than the lower monthly age group (60-63 months). (4) The CAS scores of the children with tendencies towards hyperactivity was lower than that of normal children. (5) The CAS profile of 5-year-old children was divided into 4 groups with distinctive characteristics by means of K-mean cluster analysis.

• The Journal of Information Systems
• /
• v.29 no.1
• /
• pp.1-22
• /
• 2020

Purpose Along with increasing use of mobile devices, the sharing economy platform services, which generate profits by sharing products owned or labor, have been activated. A representative example of the sharing economy platform service is Airbnb, which connects providers having idle residential space with users. The results revealed that the cases of superhosts and professional companies had a positive and negative effect on user satisfaction, respectively. Based on signaling theory, this study drew the following implications: residential space providers should make an effort to meet the superhost conditions suggested by Airbnb, and offering residential spaces by individual suppliers rather than professional accommodation companies can more heighten user satisfaction. Design/methodology/approach Because sharing behavior is promoted through trust between interested parties, this study aimed to verify the effects of provider characteristics on user satisfaction in a sharing economy platform service. Specifically, it analyzed user satisfaction, according to host attributes (i.e., "superhost or not," gender, and "professional company or not") among the characteristics of Airbnb suppliers. Findings The results revealed that the cases of superhosts and professional companies had a positive and negative effect on user satisfaction, respectively. Based on these analyses results, this study drew the following implications: residential space providers should make an effort to meet the superhost conditions suggested by Airbnb, and offering residential spaces by individual suppliers rather than professional accommodation companies can more heighten user satisfaction.

• International Journal of Aerospace System Engineering
• /
• v.2 no.1
• /
• pp.43-46
• /
• 2015

Aeroelastic gust response analysis plays an important role in design of aircrafts. For gust response analysis, frequency domain aerodynamics method has been typically used with generalized aerodynamic influence coefficient matrices at various reduced frequencies. However, it cannot be applied to the aeroservoelastic analysis, such as gust alleviation control. Time-domain state space (SS) models must be built. It attacks little attention that gust response analysis relies on continuous gust time-domain input signal in terms of its PSD function. The aim the current study is to provide a reduced-order modeling (ROM) method based on CFD to model gust responses for continuous gust responses for continuou gust inputs in time domain. The paper analyzed the gust response of AGARD445.6 wing subjected to the Dryden gust with ROMs and compared the difference between the rigid structure and elastic one. The results demonstrate that structure elastic effect effect should be considered in the design of aircraft.