• Title/Summary/Keyword: object function

Search Result 1,594, Processing Time 0.027 seconds

Automatic gasometer reading system using selective optical character recognition (관심 문자열 인식 기술을 이용한 가스계량기 자동 검침 시스템)

  • Lee, Kyohyuk;Kim, Taeyeon;Kim, Wooju
    • Journal of Intelligence and Information Systems
    • /
    • v.26 no.2
    • /
    • pp.1-25
    • /
    • 2020
  • In this paper, we suggest an application system architecture which provides accurate, fast and efficient automatic gasometer reading function. The system captures gasometer image using mobile device camera, transmits the image to a cloud server on top of private LTE network, and analyzes the image to extract character information of device ID and gas usage amount by selective optical character recognition based on deep learning technology. In general, there are many types of character in an image and optical character recognition technology extracts all character information in an image. But some applications need to ignore non-of-interest types of character and only have to focus on some specific types of characters. For an example of the application, automatic gasometer reading system only need to extract device ID and gas usage amount character information from gasometer images to send bill to users. Non-of-interest character strings, such as device type, manufacturer, manufacturing date, specification and etc., are not valuable information to the application. Thus, the application have to analyze point of interest region and specific types of characters to extract valuable information only. We adopted CNN (Convolutional Neural Network) based object detection and CRNN (Convolutional Recurrent Neural Network) technology for selective optical character recognition which only analyze point of interest region for selective character information extraction. We build up 3 neural networks for the application system. The first is a convolutional neural network which detects point of interest region of gas usage amount and device ID information character strings, the second is another convolutional neural network which transforms spatial information of point of interest region to spatial sequential feature vectors, and the third is bi-directional long short term memory network which converts spatial sequential information to character strings using time-series analysis mapping from feature vectors to character strings. In this research, point of interest character strings are device ID and gas usage amount. Device ID consists of 12 arabic character strings and gas usage amount consists of 4 ~ 5 arabic character strings. All system components are implemented in Amazon Web Service Cloud with Intel Zeon E5-2686 v4 CPU and NVidia TESLA V100 GPU. The system architecture adopts master-lave processing structure for efficient and fast parallel processing coping with about 700,000 requests per day. Mobile device captures gasometer image and transmits to master process in AWS cloud. Master process runs on Intel Zeon CPU and pushes reading request from mobile device to an input queue with FIFO (First In First Out) structure. Slave process consists of 3 types of deep neural networks which conduct character recognition process and runs on NVidia GPU module. Slave process is always polling the input queue to get recognition request. If there are some requests from master process in the input queue, slave process converts the image in the input queue to device ID character string, gas usage amount character string and position information of the strings, returns the information to output queue, and switch to idle mode to poll the input queue. Master process gets final information form the output queue and delivers the information to the mobile device. We used total 27,120 gasometer images for training, validation and testing of 3 types of deep neural network. 22,985 images were used for training and validation, 4,135 images were used for testing. We randomly splitted 22,985 images with 8:2 ratio for training and validation respectively for each training epoch. 4,135 test image were categorized into 5 types (Normal, noise, reflex, scale and slant). Normal data is clean image data, noise means image with noise signal, relfex means image with light reflection in gasometer region, scale means images with small object size due to long-distance capturing and slant means images which is not horizontally flat. Final character string recognition accuracies for device ID and gas usage amount of normal data are 0.960 and 0.864 respectively.

Example of Legislation on the Space Relations of Every Countries in the World and Main Contents of the Space Exploration Promotion Act and Future Task in Korea (세계 각국의 우주관계 입법례와 우리나라 우주 개발진흥법의 주요내용 및 앞으로의 과제)

  • Kim, Doo-Hwan
    • The Korean Journal of Air & Space Law and Policy
    • /
    • v.20 no.1
    • /
    • pp.9-43
    • /
    • 2005
  • The Korean government established her first "National Space Program" in 1996, and revised it in 2000 and 2005. As embedded in the National Space Program, Korea aims to become one of the world's top countries in space technology by 2010. All of 13 satellites are planned to be put into orbit as schematized, which include 7 multi-purpose satellites, 4 science satellites and 2 geostationary orbit satellites. The Space Center in Korea is to be built at Woinara-Do, Bongrae-Myon, Koheung-Goon, Junlanam Province on the southern coast of the Korean peninsular. The first phase of the construction of the space center will be finished by 2007 for launch of KSLV-l. This will make Korea be the 13th advanced country in space development having a launching site in the world. The "Space Center" will serve as the infrastructure for the development of space technology and related technology, and plan to launch a low earth orbit satellite in 2007. A second science satellite made in Korea will be launched from the space center by 2007. From 2010, the center will be operated on a commercial basis operating launch facilities for low-to mid-altitude orbit satellites. Since the 'Aircraft Industry Promotion Act' was replaced by the 'Aerospace Industry Development Promotion Acf of 1987, this Act had been amended seven times from 1991 year to 2004. Most of developed countries has been enacted the space law including the public or private items such as an (1)DSA, (2)Russia, (3)the United Kingdom, (4)Germany, (5)France, (6)Canada, (7)Japan, (8)Sweden, (9)Australia, (10)Brazil, (11)Norway, (12)South Africa, (13)Argentina, (14)Chile, (15)Ukrainian etc. As the new Space Exploration Promotion Act was passed by the resolution of the Korean Congress on May 3, 2005, so the Korean government has made the public proclamation the abovementioned Act on May 31, this year. This Act takes effect on December 1, 2005 after elapsing six months from the date of promulgation. The main contents of Space Exploration Promotion Act of 2005 is as the following (1)establishing a basic plan for promoting space exploration, (2)establishment and function of national space committee, (3)procedure and management of domestic and international registration of space objects, (4)licensing of launch by space launch vehicles, (5)lability for damages caused by space accidents and liability insurance, (6) organizing and composition of the space accident investigation committee, (7)Support of non-governmental space exploration project, (8)Requesting Support and Cooperation of Space Exploration, (9)Rescue of Astronauts and Restitution of Space Objects, etc.. In oder to carry out successfully the medium and long basic plan for promoting space exploration and to develope space industry in Korea, I think that it is necessary for us to enlarge and to reorganize the function and manpower of the Space Technology Development Division of the Ministry of Science & Technology and the Korea Aerospace Research Institute. Korea has been carrying out its space program step by step according to the National Space Program. Korea also will continually strengthen the exchange and cooperation with all the countries in the world under the principle of equality, friendship relations and mutual benefits. Together with all other peoples around the globe, Korea will make due contribution towards the peaceful utilization of space resources and promotion of human progress and prosperity.

  • PDF

Development of Computer Program for the Arrangement of the Forest-road Network to Maximize the Investment Effect on the Forest-road Construction (임도개설(林道開設)에 있어서 투자효과(投資效果)를 최대(最大)로 하는 임도배치(林道配置)프로그램 개발(開發))

  • Park, Sang-Jun;Son, Doo-Sik
    • Journal of Korean Society of Forest Science
    • /
    • v.90 no.4
    • /
    • pp.420-430
    • /
    • 2001
  • The object of this study is to develop a computer program for the arrangement of the forest-road network maximizing the investment effect in forest-road construction with factors such as terrains, forest physiognomy, management plan, logging system, cost of forest-road construction, capacity of inputted labour, capacity of timber production and so on. The operating system developed by this study is Korean Windows 95/98 and Microsoft Visual Basic ver. 5.0. User interface was designed as systematic structure, it is presented as a kind of GUI(graphic user interface). The developed program has result of the most suitable forest-road arrangement, has suitable forest-road density calculated with cost of logging, cost of forest-road construction, diversion ratio of forest-road, cost of walking in forest. And the most suitable forest-road arrangement was designed for forest-road arrangement network which maximized investment effect through minimizing the sum of cost of logging and cost of forest-road construction. Input data were divided into map data and control data. Digital terrain model, division of forest-road layout plan, division of forest function and the existing road network are obtained from map data. on the other hand, cost of logging related terrain division, diversion ratio of forest-road and working road, cost of forest-road construction, cost of walking, cost of labor, walking speed, capacity of inputted labor, capacity of timber production and total distance of forest-road are inputted from control data. And map data was designed to be inputted by mesh method for common matrix. This program can be used to construct a new forest-road or vice forest-road which compensate already existing forest-road for the functional forestry.

  • PDF

Philosophic Investigation of the 'Ghi(氣)' Phenomena ('기(氣)' 현상에 대한 철학적 고찰)

  • Lee, Hyun-Ju
    • Journal of East-West Nursing Research
    • /
    • v.3 no.1
    • /
    • pp.50-67
    • /
    • 1998
  • When recognition of the Ghi(氣) which exist in all things, is changed on the aspects of the science of nursing, the view of health and nursing will be more efficient and can be developed as the proper concept for Korean culture. I think it is nessary to confirm which philosophical basis of the will be applicable to nursing and how to it has to be developed. Therefore I can for the research of the Ghi phenomena to attain the Thoughts of philosophy that is appropriate to expound those phenomena. And I attempt to induct "the fusion of horizons" to unify the view of the I world between Korea and the West. The Ghi is very energetic and omnipresent among the universe, Nature, and the human being. So it can organize all the primary elements of mental and I physical function of human as like life, mind, breath, feeling, energy, etc. A general concept of the Ghi is described as follows ; (1) The Ghi is the origin and essence to organize the universe, Nature, and the human being. (2) It is the perpetually movable thing. (3) And there are continuous transmission between the Ghi of the universe and the human through 'body, mind, and soul. For review on the philosophic basis of the Ghi, I studied out the identity of the doctrine of Li and Ch'i(理氣論) in the field of philosophy of Korea and the West. In Korea, the concept of the Vigor is based on Ch'i monolism(기일원론) and Li Ch'i dualism (이기이원론) of Yul-gok Lee's, Toi-kye Lee's, Hwa-dam's, and/or Hekang's. These are indispensable for the view of the world of Korea as Metaphysical ideology, Concrete science, Materialism, Ontology, and Epistemology. From the viewpoint of the philosophy of the West, the doctrine of Li and Ch'i(이기론) of Korea is identical with the doctrine of Li and Ch'i(이기론) of Joo-ja, Idea of Plato, Metaphysics of Aristotle, World Spirit(Weltgeist) of Hegel, and Existentialism of Heidegger. In the nursing theory of the West, some of them referred to the Ghi as like Energy field theory of Rogers and Energy exchange of Neuman. Though there are different in terminology, "energy" and the "Ghi" are induced comparable therapeutic action between the human and the environments. With the nursing theory of Korea, I have made an attempt to compare the Ghi with metaparadigm of nursing-the human being, the environment, the health, and the nursing. For the most part, the alternative therapy is resonable to the frame of the nursing theory of Korea. It is easy to apply alternative therapy on the every spot of nursing. So this therapy could be a kind of forms as nursing therapy in the nursing centers where take the duties of supporting in local societies. In result, independent nursing intervention will be activated by the nurse who puts up with the major parts. It is available to apply this therapy to palliation of pain, insomnia of infant, Sanhujori (산후조리), pain of menstruation, arthritis. And the alternative therapy makes it possible to propose the nursing model which represent originality, tradition, and history of the nursing of Korea. Additionally, in the field of the nursing, it is indispensable to choose a suitable methodology which is considered whether it is matched with a theory of philosophy in the boundary and object of the research. Because there are many way to get the knowledge of nursing related to the Ghi. In the science of nursing, context of sociocultural background and frame are required to understand the person who need to take care of (nursing client). But the value systems of the West and the East are distinctive each other as well as the behavior of health persuance. Therefore it is the basic research data of great worth to review philosophical the Ghi phenomena which is well known to Korean.

  • PDF

Mathematics and Society in Koryo and Chosun (고려.조선시대의 수학과 사회)

  • Joung Ji-Ho
    • The Mathematical Education
    • /
    • v.24 no.2
    • /
    • pp.48-73
    • /
    • 1986
  • Though the tradition of Korean mathematics since the ancient time up to the 'Enlightenment Period' in the late 19th century had been under the influence of the Chinese mathematics, it strove to develop its own independent of Chinese. However, the fact that it couldn't succeed to form the independent Korean mathematics in spite of many chances under the reign of Kings Sejong, Youngjo, and Joungjo was mainly due to the use of Chinese characters by Koreans. Han-gul (Korean characters) invented by King Sejong had not been used widely as it was called and despised Un-mun and Koreans still used Chinese characters as the only 'true letters' (Jin-suh). The correlation between characters and culture was such that, if Koreans used Han-gul as their official letters, we may have different picture of Korean mathematics. It is quite interesting to note that the mathematics in the 'Enlightenment Period' changed rather smoothly into the Western mathematics at the time when Han-gul was used officially with Chinese characters. In Koryo, the mathematics existed only as a part of the Confucian refinement, not as the object of sincere study. The mathematics in Koryo inherited that of the Unified Shilla without any remarkable development of its own, and the mathematicians were the Inner Officials isolated from the outside world who maintained their positions as specialists amid the turbulence of political changes. They formed a kind of Guild, their posts becoming patrimony. The mathematics in Koryo significant in that they paved the way for that of Chosun through a few books of mathematics such as 'Sanhak-Kyemong', 'Yanghwi-Sanpup' and 'Sangmyung-Sanpup'. King Sejong was quite phenomenal in his policy of promotion of mathematics. King himself was deeply interested in the study, createing an atmosphere in which all the high ranking officials and scholars highly valued mathematics. The sudden development of mathematic culture was mainly due to the personality and capacity of king who took anyone with the mathematic talent into government service regardless of his birth and against the strong opposition of the conservative officials. However, King's view of mathematics never resulted in the true development of mathematics perse and he used it only as an official technique in the tradition way. Korean mathematics in King Sejong's reign was based upon both the natural philosophy in China and the unique geo-political reality of Korean peninsula. The reason why the mathematic culture failed to develop continually against those social background was that the mathematicians were not allowed to play the vital role in that culture, they being only the instrument for the personality or politics of the king. While the learned scholar class sometimes played the important role for the development of the mathematic culture, they often as not became an adamant barrier to it. As the society in Chosun needed the function of mathematics acutely, the mathematicians formed the settled class called Jung-in (Middle-Man). Jung-in was a unique class in Chosun and we can't find its equivalent in China or Japan. These Jung-in mathematician officials lacked tendency to publish their study, since their society was strictly exclusive and their knowledge was very limited. Though they were relatively low class, these mathematicians played very important role in Chosun society. In 'Sil-Hak (the Practical Learning) period' which began in the late 16th century, especially in the reigns of Kings Youngjo and Jungjo, which was called the Renaissance of Chosun, the ambitious policy for the development of science and technology called for. the rapid increase of he number of such technocrats as mathematics, astronomy and medicine. Amid these social changes, the Jung-in mathematicians inevitably became quite ambitious and proud. They tried to explore deeply into mathematics perse beyond the narrow limit of knowledge required for their office. Thus, in this period the mathematics developed rapidly, undergoing very important changes. The characteristic features of the mathematics in this period were: Jung-in mathematicians' active study an publication, the mathematic studies by the renowned scholars of Sil-Hak, joint works by these two classes, their approach to the Western mathematics and their effort to develop Korean mathematics. Toward the 'Enlightenment Period' in the late 19th century, the Western mathematics experienced great difficulty to take its roots in the Peninsula which had been under the strong influence of Confucian ideology and traditional Korean mathematic system. However, with King Kojong's ordinance in 1895, the traditional Korean mathematics influenced by Chinese disappeared from the history of Korean mathematics, as the school system was hanged into the Western style and the Western mathematics was adopted as the only mathematics to be taught at the Schools of various levels. Thus the 'Enlightenment Period' is the period in which Korean mathematics shifted from Chinese into European.

  • PDF

A Case Study of Software Architecture Design by Applying the Quality Attribute-Driven Design Method (품질속성 기반 설계방법을 적용한 소프트웨어 아키텍처 설계 사례연구)

  • Suh, Yong-Suk;Hong, Seok-Boong;Kim, Hyeon-Soo
    • The KIPS Transactions:PartD
    • /
    • v.14D no.1 s.111
    • /
    • pp.121-130
    • /
    • 2007
  • in a software development, the design or architecture prior to implementing the software is essential for the success. This paper presents a case that we successfully designed a software architecture of radiation monitoring system (RMS) for HANARO research reactor currently operating in KAERI by applying the quality attribute-driven design method which is modified from the attribute-driven design (ADD) introduced by Bass[1]. The quality attribute-driven design method consists of following procedures: eliciting functionality and quality requirements of system as architecture drivers, selecting tactics to satisfy the drivers, determining architectures based on the tactics, and implementing and validating the architectures. The availability, maintainability, and interchangeability were elicited as duality requirements, hot-standby dual servers and weak-coupled modulization were selected as tactics, and client-server structure and object-oriented data processing structure were determined at architectures for the RMS. The architecture was implemented using Adroit which is a commercial off-the-shelf software tool and was validated based on performing the function-oriented testing. We found that the design method in this paper is an efficient method for a project which has constraints such as low budget and short period of development time. The architecture will be reused for the development of other RMS in KAERI. Further works are necessary to quantitatively evaluate the architecture.

The difference between the two methods for myocardial performance index in children (소아에서 심근 수행 지수 측정 방법간의 차이)

  • Joung, Jae-Il;Lee, Chang-Hyun;Kim, Jae-Kwang;Park, Kie-Young;Kim, Bong-Sung;Lee, Jung-Ju;Han, Myung-Ki
    • Clinical and Experimental Pediatrics
    • /
    • v.49 no.12
    • /
    • pp.1324-1328
    • /
    • 2006
  • Purpose : The object of this study was to determine the difference between two methods for myocardial performance index(MPI) in children, using the conventional and pulsed Doppler echocardiography. Methods : A total of 27 children with anatomically normal hearts were enrolled for the study. all were examined by conventional and pulsed Doppler echocardiography at Gangneung Asan Hospital between December, 2005 and February, 2006. First, we measured the time interval(a1) between the mitral inflows from apical 4-chamber view, and the ejection time(ET1) from apical 5-chamber view. And then, we calculated MPI1, isovolumic contraction time(ICT1) and isovolumic relaxation time (IRT1). Secondly, we measured ICT2, ET2 and IRT2 from apical 5-chamber view with a Dopper signal placed at just below junction between mitral and aortic valve at the same cardiac cycle. And then, we calculated MPI2. We compared MPI1 to MPI2. All MPIs were calculated by using the formula, MPI=(ICT+IRT)/ET. Results : The mean age was $5.7{\pm}2.2years$ old(M:F=15:12). The MPI2 was higher than MPI1: $0.277{\pm}0.083$ vs. $0.428{\pm}0.081$(MPI1 vs MPI2, P=0.000). Also, the ICT2 was higher than ICT1: $56{\pm}15msec$ vs $97{\pm}18msec$(ICT1 vs ICT2, P=0.000) and the IRT2 was higher than IRT1: $42{\pm}8msec$ vs $53{\pm}9msec$(IRT1 vs IRT2, P=0.000). But, the ET2 was lower than ET1: $260{\pm}16msec$ vs $254{\pm}14msec$ (ET1 vs ET2, P=0.01). There was, as well, positive linear correlation between MPI1 and MPI2. Conclusion : This study showed that there is a difference between MPI1 and MPI2 in connection with estimating methods. However, the two MPIs had a positive linear correlation. Judging from our results, the MPI of the new method might be a useful index of venticular global function in children.

A study of Symbolics of Chinese Liturgical Vestments (중국 제복의 상징성에 관한 연구)

  • 이선희
    • Journal of the Korean Society of Costume
    • /
    • v.18
    • /
    • pp.111-131
    • /
    • 1992
  • This thesis was designed to study Symbolics of Chinese Liturgical Vestments. Chinese who regarded the life of human beings as the combination of heaven and earth considered garments as the traditional product of the movement of nature. Accordingly, they thought human beings are the center of the universe composed by heaven and earth and the chief of all things; therefore man only can utilize clothes to distinguish from all of the colours. This views of clothes led to the development of liturgical vestments esteemed courtesy than anything else, especially the thought of courtesy associated with Conficius who regarded courtesy as the highest things and since then the theory of Five Elements and courtesy were inherited by all the adherents of Conficius. Yin and Yang Five Elements in the liturgical vestments was given absolute symbolics in both formative side and in colourful side. results of research studied in this was can be summed up as follows : 1. The crown of rites was made imitating after the system of head, horn, beard, bread of birds and beasts and that form of crown is front-circ-ular and back-rectangular meant to be towards light and dark. That the upper part of faceplace is black represented the way of heaven and lower part of red symbolized the way of earth. 2. Upper vestment of liturgical rites symbolizes heaven and outskirt represented earth. So front of outskirt is YANG and back is Yin. It is why then are going to harmonize positive and negative making front part three width and back part four width. Therefore, emperor who symbolizes heaven made the subjects recognize high and low and wore Dae-gu(大 ), Kon-bok(袞服), Bel-bok, Chui-bok, and Hyonbok according to the object and position of rites so that he may rule the country based on courtesy. 3. As an accessory of liturgical vestments, Bul, Pae-ok, Su, Dae-dai, Hyok-Dai, Kyu, and Hol were used. Before Bul was used man dressed skirt as the first waist-dress in order to conceal intimate part of the body. Pae-ok, as decoration blended with jade was worn by men of virtue, so men of virtue symbolized morality and virtue by Pae-ok. Su began from Yeok, connected with Pae-su , in Chou-dynasty is said to be originated by practical needs and they are divided into large Su and small su, and maintained as decoration to signify the class positions. Dae-dai did the work as not to loose the liturgical vestments and leather belt hang Bul and Su to begin as the function of practical use are in later years it became decoration to symboliz e the class position. Kyu was a jade used when empeor nominated feudal lords and observe ceremony to God and Hol, was held in hands to record everything not to forget. These Kyu and Hol became to offer courtesy during the time of rites and in later years it became used according to class position rather than practical use. 4. As far as colours are concerned, colours based by five colours according to YIN-YANG Five Elements theory and they were divided into a primary colour and a secondary colours. Primary colours corresponded with the theory of Five Elements each other, Blue, Red, Tellow, White, and Black symbolized ive Elements, five hour space, five directions, and five emperors. Secondary colours contradict with Blue, Red, Yellow, White and Black and another as a primary colour and they are Green, Scaret, Indigo, Violet, Hun colour, Chu colour, and Chi colour. This primary colour was used in liturgical vestments, that is, upper-vestments used black colour. This primary colour was used in liturgical vestments, that is, upper-vestments used black colour as primary colour and outskirt was used Hun colour as secondary colours. Thus symbolism in chinese liturgical vestments mainly began with heaven and earth and corresponded with YIN-YANG Five Elements Scool. They were developed as the scholary theory and Conficius and his followers in the later days and continued up to Min-dynasty.

  • PDF

Investigation of Scatter and Septal Penetration in I-131 Imaging Using GATE Simulation (GATE 시뮬레이션을 이용한 I-131 영상의 산란 및 격벽통과 보정방법 연구)

  • Jung, Ji-Young;Kim, Hee-Joung;Yu, A-Ram;Cho, Hyo-Min;Lee, Chang-Lae;Park, Hye-Suk
    • Progress in Medical Physics
    • /
    • v.20 no.2
    • /
    • pp.72-79
    • /
    • 2009
  • Scatter correction for I-131 plays a very important role to improve image quality and quantitation. I-131 has multiple and higher energy gamma-ray emissions. Image quality and quantitative accuracy in I-131 imaging are degraded by object scatter as well as scatter and septal penetration in the collimator. The purpose of this study was to estimate scatter and septal penetration and investigate two scatter correction methods using Monte Carlo simulation. The gamma camera system simulated in this study was a FORTE system (Phillips, Nederland) with high energy, general-purpose, parallel hole collimator. We simulated for two types of high energy collimators. One is composed of lead, and the other is composed of artificially high Z number and high density. We simulated energy spectrum using a point source in air. We estimated both full width at half maximum (FWHM) and full width at tenth maximum (FWTM) using line spread function (LSF) in cylindrical water phantom. We applied two scatter correction methods, triple energy window scatter correction (TEW) and extended triple energy window scatter correction (ETEW). The TEW method is a pixel-by pixel based correction which is easy to implement clinically. The ETEW is a modification of the TEW which corrects for scatter by using abutted scatter rejection window, which can overestimate or the underestimate scatter. The both FWHM and FWTM were estimated as 41.2 mm and 206.5 mm for lead collimator, respectively. The FWHM and FWTM were estimated as 27.3 mm and 45.6 mm for artificially high Z and high density collimator, respectively. ETEW showed that the estimation of scatter components was close to the true scatter components. In conclusion, correction for septal penetration and scatter is important to improve image quality and quantitative accuracy in I-131 imaging. The ETEW method in scatter correction appeared to be useful in I-131 imaging.

  • PDF

A Stochastic User Equilibrium Transit Assignment Algorithm for Multiple User Classes (다계층을 고려한 대중교통 확률적사용자균형 알고리즘 개발)

  • Yu, Soon-Kyoung;Lim, Kang-Won;Lee, Young-Ihn;Lim, Yong-Taek
    • Journal of Korean Society of Transportation
    • /
    • v.23 no.7 s.85
    • /
    • pp.165-179
    • /
    • 2005
  • The object of this study is a development of a stochastic user equilibrium transit assignment algorithm for multiple user classes considering stochastic characteristics and heterogeneous attributes of passengers. The existing transit assignment algorithms have limits to attain realistic results because they assume a characteristic of passengers to be equal. Although one group with transit information and the other group without it have different trip patterns, the past studies could not explain the differences. For overcoming the problems, we use following methods. First, we apply a stochastic transit assignment model to obtain the difference of the perceived travel cost between passengers and apply a multiple user class assignment model to obtain the heterogeneous qualify of groups to get realistic results. Second, we assume that person trips have influence on the travel cost function in the development of model. Third, we use a C-logit model for solving IIA(independence of irrelevant alternatives) problems. According to repetition assigned trips and equivalent path cost have difference by each group and each path. The result comes close to stochastic user equilibrium and converging speed is very fast. The algorithm of this study is expected to make good use of evaluation tools in the transit policies by applying heterogeneous attributes and OD data.