• 제목/요약/키워드: congestion effects

Search Result 236, Processing Time 0.022 seconds

A Study on the Operation Boundary of Ramp Metering System (진입제어 전략 적용 시 적정 운영영역 설정에 관한 연구)

  • Kim, Kyu-Ok;Park, Joon-Hyeong;Park, Ji-Eun;Shin, Hee-Cheol
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.10 no.2
    • /
    • pp.9-21
    • /
    • 2011
  • The ramp metering strategy is one of the effective ways to solve the freeway traffic congestion in peak time periods. The study was initiated with assurance that the traffic conditions of ramp and mainline that mitigate the congestion would exist. Under the moderate traffic volume levels, ramp metering is expected to improve the quality of freeway operation. To derive a range of traffic condition, three operation strategies(Do nothing, ramp metering, minimum ramp control) were set up and the ALINEA algorithm was implemented with microscopic traffic simulator "VISSIM". The volumes of mainline and ramp are key parameters for the simulation scenarios. Measures of effectiveness for the study include mainline density and average vehicle speed. Operation boundaries in terms of traffic volume were proposed for operating ramp metering strategy. The results show that under the proposed traffic conditions the ramp metering was more successful to increase average vehicle speeds. Traffic controls under the operation boundaries of traffic levels give significant effects for density and average vehicle speed. The outcomes of this study would be useful to improve the performance of ramp metering strategies.

Analysis of Open Toll Segments in Urban Freeways (개방식고속도로 통행특성과 영업체계 전환분석)

  • Nam, Du-Hui
    • Journal of Korean Society of Transportation
    • /
    • v.25 no.5
    • /
    • pp.101-109
    • /
    • 2007
  • Two variations of toll roads exist: mainline toll plazas and entry/exit tolls. On a mainline toll system(open toll scheme), all vehicles stop at various locations along the highway to pay a toll. While this may save money from the lack of need to construct tolls at every exit, it can cause lots of traffic congestion, and drivers could evade tolls by going around them. With entry/exit tolls, vehicles collect a ticket when entering the highway, which displays the fares it will pay when it exits, increasing in cost for distance travelled. Upon exit, the driver will pay the amount listed for the given exit. The pressures on the Seoul ring roadway network have been changing over time. In the past, the emphasis was on mobility and maintenance of the road network to provide an efficient transportation network, but recently, road use has outstripped the network's ability to extend and expand the road network and hence the policy emphasis has moved towards reducing free riders rather than mitigating its effects. In addition to this pressure is an incidental pressure, which argues that provision of free ride segments generates further traffic in isolation of other factors. This paper is examining policies to reduce the burden of traffic congestion in Seoul ring roadway which is used open toll scheme for decades. One key mechanism to achieve this policy aim is automatic charging mechanism on freeway, but if a nation-wide electronic toll collection is to be implemented successfully, there are a number of prerequisites which must be place.

A Case of Adult Otitis Media with Effusion Accompanied by Atopic Dermatitis (아토피피부염을 동반한 성인 삼출성 중이염 치험례)

  • Song, Ji-Hoon;Yu, Pei-Yen;Kim, Jong-Han;Jung, Min-Yeong;Choi, Jung-Hwa;Park, Soo-Yeon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.35 no.2
    • /
    • pp.95-104
    • /
    • 2022
  • Objectives : This study is to report a case of otitis media with effusion accompanied by atopic dermatitis improved by Korean medicine monotherapy. Methods : A 31-year-old woman patient visited our clinic for aural fullness, hearing loss, and tinnitus of the left ear on August 14th, 2021. She also had abdominal pain, diarrhea, and general weakness because of side effects of antibiotics. Besides, she had nasal congestion, rhinorrhea, and dry skin. Through otoscopy, her tympanum was fully filled with yellow effusion. She only took Korean medicine therapy including acupuncture and herbal medicine weekly. The treatment continued for about 4 months(total 14 visits) until December 4th, 2021. Otoscopy, numerical rating scale(NRS), scoring atopic dermatitis(SCORAD) index were used to assess the symptoms. Results : On August 30, 2021, her intestinal symptoms improved. The left tympanum was recovered to normal condition as the treatment continued. The effusion disappeared on October 16th, 2021. On November 6th, 2021, peritympanic blood congestion also almost alleviated. Subjective symptoms including aural fullness, hearing loss, and tinnitus disappeared on October 16, 2021. Nasal symptoms and dry skin also improved. The SCORAD index dropped from 15 to 4. Conclusions : These results suggests that otitis media with effusion can be sufficiently managed by Korean medicine therapy. Further, active application of Korean medicine therapy to common otolaryngological diseases is necessary.

The Effects of Aroma Therapy on Allergic Symptoms, Eosinophil, and the Quality of Life related to Rhinitis in University Students with Allergic Rhinitis (아로마 에센셜 오일 적용이 알레르기 비염 대학생의 비염증상, 호산구 및 비염 관련 삶의 질에 미치는 영향)

  • Won, Su Jin;Chae, Young Ran
    • Korean Journal of Adult Nursing
    • /
    • v.27 no.4
    • /
    • pp.438-448
    • /
    • 2015
  • Purpose: The purpose of this study was to identify the effects of using aroma essential oils on allergic symptoms, eosinophils and quality of life related to rhinitis for university students with allergic rhinitis. Methods: A randomized controlled experimental design was used. There were 37 participants in the experimental group, and 30 in the control group. The experimental group applied the essential oils four times a day in the nasal area as well as using inhalation of the oils each night for four weeks. Rhinoconjunctivitis quality of life questionnaire was composed of 28 questions regarding seven areas associated with allergic reactions. The data were analyzed with SPSS/WIN 21.0 program. Results: Rhinitis symptom index, nose itching (p<.001), sneezing (p<.001), watery rhinorrhea (p<.001), and nose congestion (p<.001) all had significant difference for the participants in the treatment group. Further there were significant differences in eosinophils both for measured time and interaction (p<.001). For the quality of life related to rhinitis, the results showed significant difference (p<.001). Conclusion: Using aroma therapy by applying essential oils turned out to be an effective nursing intervention that can be utilized in the easing of allergic symptom and the decrease of eosinophils, causing improvement in the quality of life related to rhinitis.

Analysis of Rebound Effect from Road Extension in Seoul, Busan, Daegue, and Incheon (도로연장에 대한 반등효과 분석 -서울, 부산, 대구, 인천을 중심으로-)

  • Lee, Min Ha;Cho, Yongsung
    • Environmental and Resource Economics Review
    • /
    • v.26 no.2
    • /
    • pp.173-203
    • /
    • 2017
  • The existence of rebound effect from road extension in Korea has been quantitatively verified using cross-sectional, time series data on four major cities - Seoul, Busan, Daegue and Incheon - between 2000 and 2013. The linear mixed effects model was constructed from six variables: total vehicle miles traveled (VMT), road extension, public transport users, gross regional domestic product (GRDP), regional population and fuel consumption. The main results can be summarized as VMT is positively correlated to road extension while negatively with public transport users. It indicates that the road extension-centered "supply-side" transportation policy induces "additional travel" and create "generated traffic" by enhancing driving efficiencies directly, or degrading other transport modes indirectly. Hence, the ultimate goal of road congestion reduction requires public transport-centered "demand management" rather than current supply-side policies.

Carbon Reduction Effect of Traffic Operational Methods Itemized in National Project for Advanced Traffic Operation and Management (교통운영체계선진화의 탄소감축 효과 연구)

  • Kim, Wonchul;Kim, Jin-Tae
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.32 no.1D
    • /
    • pp.1-11
    • /
    • 2012
  • The presidential council on national competitiveness and the national police agency have initiated a national project to refresh the road traffic control and operation systems to increase operational efficiency at signalized intersections. It would reduce the number of stops and delay of vehicles at intersections and thus mitigate congestion and emission. Although significant reduction of carbon is expected as a consequential result, such effects has yet been studied since traffic operation was behind of interest in the field of green transportation where planning was mainly involved. This paper delivers the macroscopic effects of carbon reduction of the selected items of the national project: the ones managed by the police agency. The results showed that the studied items yield significant reduction of carbon: pedestrian push button operation, flashing signal operation, progression, lagging left turns, permitted left turn, and actuated left-turn operation would reduce 12.31%, 3.27%, 2.44%, 0.97%, 0.81%, and 0.72% of the total amount of carbon emitted a year in a whole transportation sector, respectively.

Using Disaggregate Behavioral Analyze to Measure the Effects of Telecommuting on Transportation (개별행태분석을 통한 통신업무(Telecommuting)의 교통대체효과 추정)

  • 김형철;박규영;김흥준
    • Journal of Korean Society of Transportation
    • /
    • v.17 no.2
    • /
    • pp.7-19
    • /
    • 1999
  • The Purpose of this study is to analyze the impact of telecommuting-the use of telecommunications technology to perform work from remote sites- on the transportation system. It examined the effects of telecommuting on commuter travel. After reviewing case studies of foreign countries and their telecommuting characteristic, two types of survey, RP(Revealed Preference) and SP (Stated Preference), were carried out in order to analyze the impact of telecommuting on traffic. The RP survey examined respondents'attitudes toward information technology and the characteristics of their work. The SP survey asked respondents what conditions would make them want to become a telecommuter. It was found that higher salaries and communication subsidies would induce more people to telecommute. Overall, it was found that if telecommuting were to be executed in Seoul, 49.1% of workers would become telecommuters, which would result in a 14,407 billion won reduction in direct and indirect transport costs per year. This research proves that traffic congestion can be reduced effectively by instituting telecommuting as an option for workers.

  • PDF

AN EXPERIMENTAL STUDY ON THE EFFECTS OF DOG'S PULPAL HEALING AFTER COBALT-60 IRRADIATION (성견에 있어서 Cobalt-60 조사가 치수치유과정에 미치는 영향에 관한 연구)

  • Park, Dong-Soo
    • Restorative Dentistry and Endodontics
    • /
    • v.9 no.1
    • /
    • pp.15-24
    • /
    • 1983
  • Irradiation is frequently employed as the sole therapy for oral cancer. These irradiated patients presents peculiar and progressive dental problems. But there is only scanty informations concerning specific approaches to endodontic treatment for head and neck cancer patients who have been subjected to tumorcidal doses of radiation therapy. The purpose of the present study was to determine the effects of cobalt-60 radiation on the pulpal healing of dogs after the direct pulp capping. As the experimental animals, 10 dogs (above 7-8 months after birth) were divided into 3 groups (Control, Group I, Group II). The cobalt-60 was irradiated to the Group I and Group II each 1,009 and 1,562.5 rads as single dose. As the capping material Dycal$^{(R)}$(L.D. Caulk company) was selected. After the direct pulp capping the dogs were sacrified 1, 2, 3, 4, week interval and made the original slides cut with a thickness of 8 microns and stained with hematoxylin and eosin. After examination and comparision of all specimen, the results of this study were drawn as follows; 1. The formation of reparative dentin was observed from the 1st week in the Control group, the 2nd week in the Group I & II. The few and irregular tuble structure was appeared in the 4th week in the Control group only, but failed in the Group I & II. 2. The continuity of dentin bridge was appeared in the 3rd week in all group and the degeneration of odontoblast in the 1st week of the Group II. 3. The congestion and hemorrhage in the pulp tissue were observed in all groups until 3rd week. The inflammation was appeared within the 2nd week in the Group I and especially marked in the Group II, but absent in the Control group. 4. In cases Dycal into the pulp tissue deeply, the local necrosis of pulp and decrease of dentin formation was observed.

  • PDF

Effects of kinesiology tape after enucleation of mandibular dentigerous cysts

  • Kim, Min-Gyu;Kim, Moon-Young
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.46 no.2
    • /
    • pp.108-115
    • /
    • 2020
  • Objectives: Kinesiology tape (KT) creates a pulling force on the skin, thus improving blood and lymph flow by alleviating hemorrhage and congestion of lymphatic fluid. The authors hypothesized that the use of KT could be beneficial for the management of complications after head and neck surgery and designed this study to evaluate the effects of KT on swelling, pain, and trismus after enucleation of mandibular dentigerous cysts with third molar extraction. Materials and Methods: Forty patients who underwent enucleation of a dentigerous cyst with extraction of the mandibular third molar were selected. The patients were randomized into two groups (n=20 each): a KT group, where KT was applied after surgery in addition to basic postoperative care, and a control group, where patients received basic postoperative care without KT application. Swelling, pain, and trismus were evaluated before surgery (T0) and on postoperative days 1 (T1), 2 (T2), and 3 (T3). Cyst volume, gauze weight for assessing bleeding, and operation time were recorded. Results: There was a significant difference between the two groups in the change in swelling up to T1 and the change in swelling between T1 and T2. The maximum swelling in the KT group was significantly less than that in the No-KT group and maximum swelling appeared faster in the KT group than in the No-KT group. Both groups showed a mild pain response but there was no significant difference between the two groups. There was no significant difference on interincisal distance change between the two groups. There were no correlations between cyst volume, bleeding, operation time, and maximum swelling. Conclusion: KT can effectively manage facial swelling after oral and maxillofacial surgeries such as cyst enucleation and third molar extraction, thus improving postoperative patient satisfaction levels and quality of life.

Preventive Effects on Transmissible Gastroenteritis Using by TGEV Antiserum II. Clinical Sign, Histopathological and Immunohistochemical Findings (항혈청 투여에 의한 돼지 전염성 위장염의 예방효과 II.임상검사, 병리조직학적 검사, 면역조직화학적 검사)

  • Chi, Yong-Zhe;Han, Jeong-Hee;Kwon, Hyuk-Moo;Jeong, Hyun-Kyu
    • Korean Journal of Veterinary Pathology
    • /
    • v.7 no.1
    • /
    • pp.43-54
    • /
    • 2003
  • The purpose of this study was to investigate protective effects against transmissible gastroenteritis virus (TGEV) infection in piglets by administration of the TGEV antiserum orally at 2hrs, 24hrs and 36hrs after birth. Five piglets administered with the TGEV antiserum were experimentally challenged with TGEV at four-day-old. Control group was four piglets challenged with TGEV only. Clinical signs and gross, histopathological and immunohistochemical findings were examined. In clinical signs, piglets of the control group appeared the typical signs such as severe watery diarrhea, depression and anorexia but piglets of the TGEV antiserum adminstered group recovered progressively. In clinical signs, piglets of the control group appeared the typical signs such as severe watery diarrhea, depression and anorexia but piglets of the TGEV antiserum adminstered group recovered progressively. In mortality, control group showed 75%, but TGEV antiserum adminstered group showed 20.0 %, respectively. In gross findings, piglets of the control group appeared the typical findings of congestion, distension of lumen, contaning curdes of undigested milk in stomach. But gross findings of piglets of the TGEV antiserum adminstered group appeared milder than them of control group. In histopathological findings, piglets of the control group appeared the typical findings of villous atrophy and fusion, congesion, exfoliation, vacuolation, squamation, loss of cilia and proliferation of crypt. But histopathological findings of piglets of the TGEV antiserum adminstered group appeared milder than them of control group. In immunohistochemical findings, piglets of the TGEV antiserum adminstered group showed more intensive in reaction for IgA and IgG than them of control group. The recation for IgA was stronger than that of IgG. It was concluded that oral administration of TGEV antiserum to piglets was effective to prevent TGEV infection and reduce their mortality.

  • PDF