• Journal of the Korean earth science society
• /
• v.28 no.3
• /
• pp.343-356
• /
• 2007

This paper explored the characteristics of the interannual sea surface temperature (SST) variability in the equatorial Pacific by analyzing the simulated data from a newly coupled general circulation model (CGCM). The CGCM simulates well the realistic ENSO variability as well as the mean climatologies including SST, seasonal cycle, precipitation, and subsurface structures. It is argued that the zonal gradient of SST in the equatorial Pacific is responsible for the over-energetic SST variability near the equatorial western boundary in the model. This variability could also be related to the strong westward propagation of SST anomalies which resulted from the enhanced the zonal advection feedback. The simple two-strip model supports this by sensitivity tests. Analysis of the relationship between zonal mean thermocline depth and NINO3 SST index suggested that the ENSO variability is controlled by the recharge-discharge oscillator of the model. The lead-lag regression result reveals that heat buildup process in the western equatorial Pacific associated with the increase of the barrier layer thickness (BLT) is a precedent condition for El $Ni\widetilde{n}o$ to develop.

• Physical Therapy Korea
• /
• v.18 no.2
• /
• pp.67-75
• /
• 2011

The purpose of this study was to investigate the effects of virtual reality (VR) therapy with compensation inhibition and feedback (CIF) on upper extremity function in chronic stroke patients. Seven chronic stroke patients participated in this study, which was a randomized controlled trial with a crossover design. Self upper extremity exercise, conservative VR therapy, and VR therapy with CIF were performed for one hour per session, 5 times per week, over a 3 week period. The main outcome measures involved range of motion (ROM) including shoulder, elbow, and wrist joints, a Manual Function Test (MFT), and a Motor Activity Log (MAL). Data were calculated as posttest and pretest changes in every session and were analyzed using Friedman and Wilcoxon signed-rank tests at p<.05. The results were as follows: 1) Statistically significant increase in ROM measurements of shoulder and elbow joints were seen with VR therapy with CIF compared to VR therapy and self upper extremity exercise (p<.05), whereas no significant increasing was noted for the wrist joint (p>.05). 2) Statistically significant increase in the MFT was seen with VR therapy with CIF compared with VR therapy and self upper extremity exercise (p<.05). 3) VR therapy with CIF also resulted in statistically significant increase in both activity of use (AOU) (p<.05) and quality of movement (QOM) (p<.05) on the MAL test when compared with VR therapy and self upper extremity exercise, respectively. In conclusion, VR therapy with CIF was more effective than conservative VR therapy and self upper extremity exercise in improving the upper extremity function in hemiplegic patients with chronic stroke.

• The Journal of Engineering Geology
• /
• v.24 no.3
• /
• pp.343-351
• /
• 2014

Tunnel face mapping plays an important role in risk analysis and infrastructure support decisions during tunnel construction. In this study, a digital mapping system using a mobile device is employed instead of existing face-mapping methods that rely upon face mapping sheets. The mobile device is then connected to the main server in the field, where a tunnel-specific database is compiled automatically. This information provides real-time feedback on the tunnel face to construction personnel and engineers, thus allowing for rapid assessment of tunnel face stability and infrastructure needs. The Douglas-Peucker algorithm, among others, is employed to resolve problems arising from the detailed mapping and speed problem by data accumulation. This system is expected to raise program optimization through field verification and additional functional improvements.

• Journal of Engineering Education Research
• /
• v.14 no.2
• /
• pp.40-50
• /
• 2011

This study is to investigate an effective instruction for female students in an engineering classroom through gender -sensitive teaching strategies by analysing recorded classroom instruction, reflective journals of professor, and mentoring instructions of A professor teaching "non-steel materials and design" in an engineering classroom. This study which used a qualitative approach for data collection and analysis showed changes of A professor in his way of teaching. The changes are: making rough lesson plan ${\rightarrow}$ making detailed lesson plan being satisfied with his teaching skills ${\rightarrow}$ trying to improve his teaching skills, using negative feedback ${\rightarrow}$ using positive feedback, pointing weaknesses as pre-engineers ${\rightarrow}$ providing detailed information needed to be engineers. This paper deals with the theory comparison between a conventional engineering education and new engineering education, in which conventional models may fail to give satisfactory results. Finally, we provide real application examples to evaluate the feasibility and generality of the proposed method in this paper.

• Journal of Broadcast Engineering
• /
• v.18 no.1
• /
• pp.88-97
• /
• 2013

Collaborative filtering(CF) for the personalized recommendation is a successful and popular method in recommender systems. But the mainly researched and implemented cases focus on dealing with independent items with explicit feedback by users. For the domain of TV program recommendation in VOD service platform, we need to consider the unique characteristic and constraints of the domain. In this paper, we studied on the way to convert the viewing history of each TV program episodes to the TV program preference by considering the series structure of TV program. The former is implicit for personalized preference, but the latter tells quite explicitly about the persistent preference. Collaborative filtering is done by the unit of series while data gathering and final recommendation is done by the unit of episodes. As a result, we modified CF to make it more suitable for the domain of TV program VOD recommendation. Our experimental study shows that it is more precise in performance, yet more compact in calculation compared to the plain CF approaches. It can be combined with other existing CF techniques as an algorithm module.

• Journal of Energy Engineering
• /
• v.19 no.2
• /
• pp.128-135
• /
• 2010

This paper introduces step by step procedures for the fabrication and operation of an embedded solar tracker. The system presented consists of application software, compactRIO, C-series interface module, analogue input module, step drive, step motor, feedback devices and other accessories to support its functional stability. CompactRIO that has a real-tim processor allows the solar tracker to be a stand-alone real time system which operates automatically without any external control. An astronomical method and an optical method were used for a high-precision solar tracker. CdS sensors are used to constantly generate feedback signals to the controller, which allow a solar tracker to track the sun even under adverse conditions. The database of solar position and sunrise and sunset time was compared with those of those of the Astronomical Applications Department of the U.S. Naval Observatory. The results presented here clearly demonstrate the high-accuracy of the present system in solar tracking, which are applicable to many existing solar systems.

• The KIPS Transactions:PartB
• /
• v.9B no.1
• /
• pp.47-56
• /
• 2002

In the distributed multimedia document system, media objects distributed over a computer network are retrieved from their sources and presented to users according to specified temporal relations. For effective presentation, synchronization has to be supported. Furthermore, since the presentation in the distributed environment is influenced by the network bandwidth and delay, they should be considered for synchronization. This paper proposes a distributed multimedia presentation system that performs presentation effectively in the distributed environment. And it also suggests a method to supports synchronization, in which, network situation and resources are monitored when media objects are transferred from servers to a client. Then a feedback message for the change of them is sent to the server so that the server might adjust the data sending rate to control synchronization. To monitor the situation of network, we use two methods together. One is to manage the level of the buffer by setting thresholds on a buffer and the other is to check the difference between the sending time of a packet from the server and the arrival time of the packet to the client.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.502-505
• /
• 2005

Researches about micro technology travel lively in these days. Such many researches are concentrated in the field of materials and a process field. But properties of micro materials should be known to give results of research developed into still more. In these various material properties, mechanical property such as tensile strength, elastic modulus, etc is the basic property. To measure mechanical properties in micro or nano scale, actuating must be very precise. PZT is a famous actuator which becomes a lot of use to measure very precise mechanical properties in micro research field. But PZT has a nonlinearity which is called as hysteresis. Not precision result is caused because of this hysteresis property in PZT actuator. Therefore feedback control method is used in many researches to prevent this hysteresis of PZT actuator. Feedback control method produce a good result in processing view, but cause a loss in a resolution view. In this paper, hysteresis is compensated by open loop control method. Hysteresis property is modeled in Mathematical function and compensated control input is constructed using inverse function of original data. Reliability of this control method can be confirmed by testing nickel thin film that is used in MEMS material broadly.

• Journal of Institute of Control, Robotics and Systems
• /
• v.19 no.7
• /
• pp.605-613
• /
• 2013

This research proposes a vibration pattern algorithm to implement the haptic joystick to control a mobile robot at the remote site without watching the navigation environment. When the user cannot watch the navigation environment of the mobile robot, the user may rely on the haptic joystick solely to avoid obstacles and to guide the mobile robot to the target. To generate vibration patterns, there is a vibration motor at the bottom of the joystick which is held by the user to control the motion direction of the mobile robot remotely. When the mobile robot approaches to an obstacle, a pattern of vibration is generated by the motor, and by feeling the vibration pattern which is determined by the relative position of the mobile robot to the obstacle, the user can move the joystick to avoid the collision to the obstacle for the mobile robot. To generate the vibration patterns to convey the relative location of the obstacle near the mobile robot to the user, Fuzzy interferences have been utilized. To measure the distance and location of the obstacle near the mobile robot, ultrasonic sensors with the ring structure have been adopted and they are attached at the front and back sides of the mobile robot. The precise location of the obstacle is obtained by fusing the multiple data from ultrasonic sensors. Effectiveness of the proposed algorithm has been verified through the real experiments and the results are demonstrated.

• Research in Community and Public Health Nursing
• /
• v.8 no.2
• /
• pp.250-261
• /
• 1997

In Korea, visiting nursing services in pubic health centers have been in place since 1991. The purpose of this study is to compare the job characteristics, job motivation and job performance between visiting nurses and other public health nurses. 196 subjects were sent mailed questionnaires from Aug. to Sep., 1997. The response rate was 65.3%. Data were analyzed by a SPSSWIN program with a t-test, $X^2-test$, ANCOVA. The results were as follows : 1. The level of job ability in visiting nurses was higher than that of other public health nurses, but it was an insignificant difference(t=1.5975, p=.2078). Among job characteristics, skill variety was significantly higher in other public health nurses(t=8.2121, p=.0046); autonomy and feedback were significantly higher in visiting nurses(t=8.1877, p=.0047/t=7.7026, p=.0085). 2. There was no significant difference in the level of job motivation(t=.6485, p=.4216) and in job performance between the two groups (t=2.7393, p=.0995). In job performance, general nursing and organizational jobs were significantly higher in other public health nurses (t=4.8486, p=.1288/t=9.4237, p=.0024). 3. It was reconfirmed that there was, a significant difference in the level of skill variety, autonomy and feedback in analyzing age and career as covariates. 4. Significant positive relationship was found in job characteristics and job motivation(r=.5488, p=.0000). No significant relationship was found in job characteristics and job performance(r=.0486, p=.498). Through these results, it was supported that there were differences in some of the job characteristics and job performance between visiting nurses and other public health nurses. Therefore, it is requested to redesign job standards, training programs and management styles focusing on the job characteristics of visiting nurses.