• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.23 no.3
• /
• pp.395-404
• /
• 2013

A pattern matching algorithm plays an important role in traffic identification and classification based on predefined patterns for intrusion detection and prevention. As attacks become prevalent and complex, current patterns are written using regular expressions, called regexes, which are expressed into the deterministic finite automata(DFA) due to the guaranteed worst-case performance in pattern matching process. Currently, because of the increased complexity of regex patterns and their large number, memory-efficient DFA from states reduction have become the mainstay of pattern matching process. However, most of the previous works have focused on reducing only the number of states on a single automaton, and thus there still exists a state blowup problem under the large number of patterns. To solve the above problem, we propose a new state compression algorithm that merges states on multiple automata. We show that by merging states with the same input character on multiple automata, the proposed algorithm can lead to a significant reduction of the number of states in the original DFA by as much as 40.0% on average.

• Journal of Advanced Navigation Technology
• /
• v.18 no.3
• /
• pp.209-214
• /
• 2014

Current black boxes have a problem of storing unnecessary imagery data recordings without data classification. For this reason, users have to erase videos every time. This method is inadequate for black boxes with limited memory capacity. In this paper, we design and implement a system that recognizes traffic accident situations and saves these recordings by classifying them according to weighted values. The system was made to save video recorded at a 30-sec interval of every event to black box folders by changing names based on weighted value data under the external environment in a 1:10 scale model car. Based on this, when the tests were performed as a major car accident while driving, the videos were created in w2 folder, and when the tests were performed as a minor car accident while stopped, the videos were created in w1 folder.

• Journal of the Korean Society for Railway
• /
• v.11 no.1
• /
• pp.54-60
• /
• 2008

In the trackbed design using elastic multilayer model, the stress-dependent resilient modulus $(E_R)$ is an important input parameter, that is, reflects substructure performance under repeated traffic loading. However, the evaluation method for resilient modulus using repeated loading triaxial test is not fully developed for practical purpose, because of costly equipment and the significantly fluctuated values depending on the testing equipment and laboratory personnel. The this study, the paper will present an indirect method to estimate the resilient modulus using dynamic properties. The resilient modulus of crushed stone, which is the typical material of sub-ballast, was calculated with the measured dynamic properties and the range of stress level of the sub-ballast, and approximated with the power model combined with bulk and deviatoric stresses. The resilient modulus of coarse grained material decreases with increasing deviatoric stress at a confining pressure, and increases with increasing bulk stress. Sandy soil (SM classified from Unified Soil Classification System) of subgrade was also evaluated and best fitted with the power model of deviatoric stress only.

• Journal of Korean Society of Transportation
• /
• v.18 no.3
• /
• pp.101-112
• /
• 2000

The Purpose of this Paper was to revise the method of USHCM and to establish new method for level of service analysis on two-lane rural highways. For this Purpose, total delay rate was selected as new MOE for level of service, replacing the present Percent time delay. This result showed that total delay rate was more effective for considering the effects of traffic flows, auxiliary lane, and vertical tirade. The application of total delay rate could resolve the Problems in the USHCM method, such as too wide ranges for level of service D and E, and the use of different Procedures for level of service analysis of general terrain segment and specific grade Procedures. The research results are as follows First, a new method for level of service analysis on two-lane rural highways was developed using the total delay rate. Second, a new classification for level of service was developed and a consistent method applicable for general terrain segment and specific tirade Procedures was developed. Third, the desired speed on two-lane rural highways was determined as 85km/h.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.16 no.4
• /
• pp.419-427
• /
• 1994

Because of the prominence of the nose and its central location, it is the most frequently encountered fractures in the face. Yet reports about the nasal bone fractures are virtually rare in the oral and maxillofacial surgical literatures. This is a retrospective study on 19 nasal bone fractures treated in Chosun university hospital Department of Oral & Maxillofacial Surgery from Jan. 1991 to Sep. 1993, under admission to our Dept. and the obtained results were as follows. 1. Of the 240 patients with facial bone fractures, 28 patients suffered nasal fractures(12%) and male to female ratio was 5.3:1. 2. The most frequent cause was traffic accidents(39%)m, the next fall down(36%), first blow(4%). 3. The age frequency was the highest in the fifth decade (32%). 4. Clinical classification of nasal fractures was simple fractures(74%), combined fractures(26%), and single fractures(37%), combined fractures(63%). 5. The most frequently combined site was maxilla(50%). 6. Treatments of nasal fractures were closed reduction(63%), open reduction(5%), and secondary rhinoplasty(32%). 7. The initial treatment time from accident was 1.7 days in single fractures, and 3.5 days in combined fractures, and the period of splint retained was about 8.2 days in single fracture, about 8.7 in combined fracture. 8. It was necessary to treat secondarily in delayed treatment, and all treatment methods showed relatively good prognosis. 9. Closed reduction was treated under local anesthesia, but open reduction & secondary rhinoplasty was treated under general anesthesia except 1 case. 10. The complications were disturbance of swellings 5 cases, ethetic problem 5 cases, epiphora 3 cases, abnormal sensation 6 cases in relation with other fractures.

• Journal of Environmental Health Sciences
• /
• v.46 no.2
• /
• pp.204-213
• /
• 2020

Objective: This study is aimed at investigating indoor air quality on public transportation (subway, train, and bus) according to changes in season and time. Methods: We evaluated TVOC and HCHO on public transportation based on the un-controlled parameters of the Ministry of Environment. We also measured temperature and humidity since they affect the concentration of TVOC and HCHO. For public transportation classification, subway lines were classified into Lines 1 to 4. Additionally, trains were classified as ITX and KTX. Results: When comparing summer and winter on public transportation, the concentrations of TVOC and HCHO did not show any particular tendency. However, the concentrations of TVOC and HCHO during traffic congestion was higher than levels during times of non-congestion on most public transportation. In summer and winter, the measurement results for temperature and humidity showed a normal range, so temperature and humidity did not affect the concentrations of TVOC and HCHO. In the case of TVOC, TVOC concentrations on new trains were found to be relatively higher than on older ones, but there was no statistically correlation. Conclusions: A survey was conducted on the indoor air quality on public transportation. This study also analyzed data based on TVOC and HCHO for designing policies and managing indoor air quality.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.11B
• /
• pp.698-706
• /
• 2005

In this paper, we investigate the parameters of the IEEE 802.11e MAC protocol, CWmin and AIFS, in terms of their capability of QoS control. The delay and the bandwidth performances are selected as the QoS medics to examine the characteristics of those parameters. A policy on MAC parameters usage, thereby, is proposed. We regard the MAC-level traffic classification as the differentiation in the channel accessibility, and thus the delay differentiation is referred to a main issue of the class-level QoS control. Realizing the tight relationship between the delay performance and the parameter AIFS, we derive an analytical expression of their relationship through an analysis of the MAC mechanism. Various simulations are examined which show the validity of our assertions, and a policy on the parameters usage is proposed based on those observations.

• Journal of Korean Foot and Ankle Society
• /
• v.3 no.1
• /
• pp.40-48
• /
• 1999

The neck of the talus is its most vulnerable and fragile segment, because of narrow diameter, devoid of hyaline padding and honeycombed internally by vascular channels etc. Talar neck fractures comprise 50% of all major to the talus. The majority occurs as a result of high-energy injuries, such as motor vehicle accidents or fall from a height. Anatomically, talar surface is covered mainly with articular cartilage and blood supply to the talus is very poor. So, complications, such as non-union, avascular necrosis and post traumatic arthritis, are frequent. The authors reviewed fourteen cases of talar neck fractures treated in our clinics from Jan. 1992 to Mar. 1997, and average follow-up period was over 15 months. The results obtained were as follows; 1. Patients' average age was 31.2 years. 2. The most common cause was traffic accident(9/14, 64%), and hyperdorsiflexion injury of the ankle was common mechanism of the fractures. 3. According to the modified Hawkins classification, type I was four cases, type II was nine cases, type III was one case and type IV was no case. 4. Hawkins sign of subcortical radiolucency was found in 64% (9/14) of the fractures. 5. Avascular necrosis was occurred in 21% (3/14) of the fractures(in two cases of type II fractures, and in one of type III). 6. According to the Hawkins criteria, four cases in type I, five in type II were an excellent result. Two cases, one in type II and one in type III were good result, and two in type II were fair. One in type II was poor result.

• Journal of Trauma and Injury
• /
• v.19 no.1
• /
• pp.1-7
• /
• 2006

Purpose: Injury is a leading cause of morbidity and mortality for children. As an injury prevention measure, the differences in external causes of severe pediatric injuries based on ICECI were analyzed according to age groups. Methods: A retrospective study was performed for pediatric patients under 15 years of age, who had been admitted to the emergency department with severe injuries from January 1998 to December 2004. The external causes of injury were investigated according to the ICECI: intent, mechanisms, places of occurrence, objects/substances producing injury, and related activities. The patients were divided into four groups based on age: infant (<0 year), toddler (1~4 years), preschool age (5~8 years), and school age (9~15 years). Results: The injury mechanisms, the places of occurrence and the related objects/substances vary with the age groups. The most common subtype of traffic accidents was pedestrian injury in pre-school age group. Falls most frequently occurred in the toddler group. But falls from a height of less than l meter height (6 patients) occurred only in the infant group. The most common place of occurrence in the infant group was the home, and that of other groups was the road. The related objects/substances for falls, for example, household furnitures and playground equipment depended on the age group. Conclusion: The age-group specific characteristics of severe pediatric injury were analyzed successfully through the ICECI. Therefore, when establishing a plan for the prevention of pediatric injury, consideration must be given to the differences in the external causes of injuries according to age group.

• Journal of the Korean Arthroscopy Society
• /
• v.2 no.2
• /
• pp.147-150
• /
• 1998

We reviewed the charts and photos taken during arthroscpy of 218 knees of 214 patients(240 menisci) retrospectively. The male was 156 cases(73%) and the female 58 cases(27%). The mean age of the patients was 35 years(range, 7-68). The patients who had definite trauma history were classified as trauma group(Group 1), and the patients who had no or could not recall trauma history were as atrauma group(Group 2). The trauma group was subclassified into the the patients with sports injury, traffic accident, fall down, slip down, direct injury, and miscellaneous according to the causes of the trauma. The patterns of meniscal tear were classified into longitudinal, bucket-handle, horizontal, transverse, flap, complex, and degenerative tear on the basis of O'Connor's classification. The aim of this study was to compare the meniscal tear patterns between trauma group(Group 1) and atrauma group(Group 2) and between the patients before and after the age of 40. The results were as follows ; 1) The difference in the incidence of tear between medial and lateral meniscus was not significant statistically. 2) In Group 1, 60% of the cases showed the longitudinal and bucket-handle tear and 52% of the cases of Group 2 were horizontal tear. 3) In the patients before the age of 40, the longitudinal and bucket-handle tear were 52% of the cases and in the patients over 40, tear patterns which were thought to be related to degenerative change, horizontal and degenerative tear were more than half of the cases (51%).