• Journal of information and communication convergence engineering
• /
• v.5 no.2
• /
• pp.171-176
• /
• 2007

To give a guarantee a consistently high level of quality and reliability of Telematics traffic service, traffic flow forecasting is very important issue. In this paper, we proposed an adaptable integrated prediction model to predict the traffic flow in the future. Our model combines two methods, short-term prediction model and long-term prediction model with different combining coefficients to reflect current traffic condition. Short-term model uses the Kalman filtering technique to predict the future traffic conditions. And long-term model processes accumulated speed patterns which means the analysis results for all past speeds of each road by classifying the same day and the same time interval. Combining two models makes it possible to predict future traffic flow with higher accuracy over a longer time range. Many experiments showed our algorithm gives a better precise prediction than only an accumulated speed pattern that is used commonly. The result can be applied to the car navigation to support a dynamic shortest path. In addition, it can give users the travel information to avoid the traffic congestion areas.

• The Korean Journal of Ecology
• /
• v.27 no.4
• /
• pp.239-244
• /
• 2004

In this review, we present the results of our ten years of study on beef cattle production as a means of preserving phytodiversity and landscape in the semi-natural grasslands of the Aso region of Japan. There are about 16,000 ha of semi-natural grasslands in the region. The grasslands are maintained for animal production through such activities as grazing, mowing, and controlled burning. The Shannon's diversity index values, as measured in the present study, were higher in the grazed sites than in the abandoned sites. The grazing activities thus seem to create suitable habitats for coexisting herbaceous species. The grassland grazed moderately over a long term was able to sustain more animals than the grassland unused over a long term.

• Korean Journal of Child Studies
• /
• v.22 no.1
• /
• pp.97-107
• /
• 2001

This study argues the nature of the microgenetic method in respect to child development research and explores its merits and limitations. The microgenetic method focuses on observations that span the entire period from the beginning of developmental change to the time it reaches a relatively stable state. This produces a high density of observations relative to the rate of change in the phenomenon. In this way, observed behavior may be used in intensive trial-by-trial analysis. The microgenetic method is superior to other methods in the possibilities for observing developmental changes as they occur, examining various aspects of change, detecting variability in behavior, and flexibility in application regardless of theoretical perspectives. Limitations of this method include reliability problems due to repeated observations, artificiality relative to the natural situation, inconsistency of short-and long-term change, and demands on children's motivation for participation in research.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.251-258
• /
• 2008

The use of reinforced earth walls in permanent structures is getting it's popularity. Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exit concerns over long-term residual deformation when subjected to repeated and/or cyclic loads, during their service period. In this investigation, the effect of preloading in reducing long term residiual deformation of back-to-back reinforced soil wall under sustained and/or repeated loading enviormentment using a series of reduced-scale model tests. It is found that the preloading technique can be an effective means of controlling residual deformations of reinforced soils under varisous loading conditions.

• Clinics in Shoulder and Elbow
• /
• v.2 no.2
• /
• pp.99-105
• /
• 1999

We investigated the effectiveness of arthroscopic decompression in stage Ⅱ subacromial impingement after long term follow up. Arthroscopic subacromial decompression was done in 104 consecutive patients who had stage Ⅱ sub­acromial impingement. After average of 8.4 years follow up, the final results were as following; 57 shoulders(55%) in excellent, 25(24%) in good, 16(15%) in fair and 6(6%) in poor. All parameters-pain, function, muscle strength and motion-were improved significantly(p<0.00l). Rotator cuff tear was developed in 10 shoulders after decompression. Among them, 8 shoulders had unfavorable results including two poor. In 6 failures, two had rotator cuff tear, three had recurrence of impingement with degenerative change and reflex sympathetic dystrophy was developed in one. Reoperations were done in 4 shoulders. Improvement of impingement symptoms was maintained in the most of patients(79%) after long term follow up. Arthroscopic decompression surgery was very effective means for stage Ⅱ impingement syndrome.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.891-898
• /
• 2009

A high rock embankment by means of dynamic compaction has hardly carried out in domestic area. For the successful accomplishment of such a high rock embankment, construction quality and measurement control are conducted. Plate loading tests are carried out to verify the bearing capacity and safety against the long term settlement. In addition, settlement of each layer is measured in order to verify the effect of dynamic compaction and to predict long term settlement.

• Korean Journal of Child Studies
• /
• v.21 no.2
• /
• pp.135-146
• /
• 2000

This study compared the effectiveness of various prevention methods(1-time video viewing; repeated video viewing; participation-enriched video viewing) used in delivering awareness of sexual abuse and coping skills to preschool children. All of the experimental groups performed better than the control group. The participation-enriched viewing group displayed higher levels of coping skills than the control and the 1-time viewing groups. Repeated viewing and participation-enriched viewing approaches were most effective in long-term understanding. The repeated viewing group showed superiority in long-term coping skills. Direct participation, interaction, and reinforcement by means of repetition are important for optimal results in sexual abuse prevention education.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.26 no.1
• /
• pp.213-232
• /
• 2000

Cetostearyl alcohol has been incorporated into cosmetic or pharmaceutial emulsions to give them an appropriate consistency and a long term stability. It is well known that cetostearyl alcohol forms a gel phase with a nonionic surfactant in an aqueous system, and the properties of the gel phase depend on several factors such as the ratio of fatty alcohols. The aim of the present Paper is to investigate the effect of the structural difference of the lipophilic part of surfactants on the stability of the gel phase in the nonionic surfactant / cetostearyl alcohol / water ternary systems using differential scanning calorimeter. It is concluded that the gel phase formed by the surfactant having the bended alkyl chain is more unstable than that formed by the case of the straight alkyl chain, and we discussed the reason why the former is more unstable after long term storage by means of the measurements of the ${\Delta}$H.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.05b
• /
• pp.792-796
• /
• 2005

The methods of times series analysis have been recognized as important tools for assisting in solving problems related to the management of water resources. Especially, After more than 40 years the so-called Hurst effect remains an open problem in stochastic hydrology. Until now, its existence has been explained fly R/S analysis that roots in early work of the British hydrologist H.E. Hurst(1951). Today, the Hurst analysis is mostly used for the hydrological studies for memory and characteristics of time series and many methodologies have been developed for the analysis. So, there are many different techniques for the estimation of the Hurst exponent(H). However, the techniques can produce different characteristics for the persistence of a time series each other. We found that DFA is the most appropriate technique for the Hurst exponent estimation for both the shot term memory and long term memory. We analyze the SOI(Southern Oscillations Index) and 6 tree-ring series for USA sites by means of DFA and the BDS statistic is used for nonlinearity test of the series. From the results, we found that SOI series is nonlinear time series which has a long term memory of H=0.92. Contrary to earlier work of Rao(1999), all the tree- ring series are not random from our analysis. A certain tree ring series show a long term memory of H=0.97 and nonlinear property. Therefore, we can say that the SOI and tree-ring series may show long memory and nonlinearity.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.12 no.2
• /
• pp.9-20
• /
• 1990

A series of 19 cases with maxillary hyperplasia and mandibular retrognathia were operated on by simultaneous superior repositioning of the maxilla after Le Fort I osteotomy and anterior repositioning of the mandible after bilateral sagittal split ramus osteotomies with or without osteotomy of the inferior border of the mandible. These were evaluated by retrospective cephalometric and computer analysis for the longitudinal skeletal and dental changes for an average of 17.1 months after surgery. For stabilization of the osteotomized segments, the authors used wire osteosynthesis by means of bilateral infraorbital and zygomatic buttress suspension wire at the maxilla, and direct interosseous wire at the split segments of the mandibular rami. Results show generally good stability after simultaneous maxillary and mandibular surgery with wire osteosynthesis, and a minimal to moderate tendency toward skeletal and dental relapse. This article is a preliminary study to defy the efficiency of the wire osteosynthesis (wo)compared with rigid internal fixation (RIF) for simultaneous maxillary and mandibular surgery. 1. The vertical relapse rate of the A point after superior repositioning of the maxilla is 2.2%. 2. The horizontal relapse rate of the B point after advancement of the mandible is 18.3%. 3. The condyle is distracted inferiorly and slightly posteriorly at the immediate postoperative period. 4. At the long term follow up examination, the condyle presents tendency of return to the preoperative position. 5. Condylar segment angle is decreased at the immediate postoperative period, and at the long term follow up evaluation, the angle is increased. 6. Gonial angle is increased at the immediate postoperative period, and then is decreased at the long term follow up evaluation. 7. The dentition is satisfactory with acceptable movement at the long term follow up evaluation. 8. At the mandibular free body analysis, genioplasty shows good stability. 9. Wire osteosynthesis provides excellent stabilization for the simultaneous maxillary and mandibular surgery.