• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.3
• /
• pp.60-67
• /
• 2016

In cumulative transfer functions, as number of transfer increase, the impact of individual transfer to transfer cost increase linearly or non linearly. This function can effectively explain various passengers's travel behavior who choose their travel routes in integrated transit line networks including bus and railway modes. Using the function, it is possible to simulate general situations such that even though more travel times are expected, less number of transfer routes are preferred. However, because travel cost with cumulative transfer function is known as non additive cost function types in route search algorithms, finding an optimal route in integrated transit networks is confronted by the insolvable enumeration of all routes in many cases. This research proposes a methodology for finding an optimal path considering cumulative transfer function. For this purpose, the reversal phenomenon of optimal path generated in route search process is explained. Also a heuristic methodology for selecting an optimal route among multiple routes predefined by the K path algorithm. The incoming link based entire path deletion method is adopted for finding K ranking path thanks to the merit of security of route optimality condition. Through case studies the proposed methodology is discussed in terms of the applicability of real situations.

• Journal of Korean Society of Transportation
• /
• v.23 no.8 s.86
• /
• pp.7-17
• /
• 2005

Transportation is from an individual mobility. Various efforts to propose specific values or the individual mobility have been conducted in diverse transportation environment. However, mobility studies for multimodal public transportation are rare especially on not the range of line but area. This study propose a method to calculate transit mobility indices as expanding mobility analysis from point-to-point to area-to-area, considering access time to transit facility, running time and transfer time of passengers. To extract mobility indices, we included walking as a lowest category of mode and set passenger car as a competitive mode to transit mode. This study propose three public transportation mobility indices as 1) how competitive public transportation facility is offered against passenger car 2) how convenient transit mode including walking is provided against passenger car from origin to destination and 3) how many various paths are presented to support passenger's travel between regions. These indices are tested on the Seoul metropolitan area with 10 lines of urban rail and about 420 lines of bus. In addition, we proposed two political applications of proposed mobility indices to increase public transportation mobility between two regions and to maximize the mobility of study area when a line is added in the area.

• Journal of the Korea Convergence Society
• /
• v.9 no.4
• /
• pp.373-380
• /
• 2018

The purpose of this study was to identify the importance and performance ranking and differences in inflight meal service quality. Data were collected from A airlines passengers. In order to secure the validity and reliability of the measurement tools, exploratory factor analysis were conducted, accordingly meal, service, cleanliness were deduced. IPA results are as follows. First, the quadrant I consisted of meal flavor, meal quality, meal menu, balanced diet, korean food availability, cleanliness of dishes, cleanliness of crew clothes. In the II quadrant, appropriate temperature, appropriateness of meal distribute time, cleanliness of the meal were found. So, the airline managers should have the most interest in these attributes and had to improve first. The quadrant III showed meal quantity, liquor diversity, polite attitude, immediate response to the meal, knowledge of the meal, meal freshness. Lastly, the quadrant IV showed a variety of beverage and special meal order. It is considered that resource allocation is necessary for minimizing the amount of resources invested to the quadrant IV, and then it should be allocated the quadrant II, which is high in importance but low in performance.

• Journal of the Korean Geographical Society
• /
• v.30 no.4
• /
• pp.352-363
• /
• 1995

This study explores horizontal equity problems in the Seoul Subway System by using costs per passenger kilometer as a comparison index. In general, subway users in the central area, except Line 1, are subsidizing users in fringe areas. Spatial differentiation of user cross subsidies in the area is due mainly to interactions between factors such as vehicle kilometers traveled, number of passengers, and length of segments. In order to decrease levels of user cross subsidies among the users and so relieve honzontal equity problems associated with subway use, it is necessary to develop a user fare system in which portions of marginal costs of subway use can be distributed properly among users. However, two-stage fare structure of the subway system in the study area is based only on trip distance, and so marginal costs associated with subway use are not properly reflected in user fees. Therefore, horizontal equity of the system in the study area is affected because of inappropriate user fees.

• The Korean Journal of Air & Space Law and Policy
• /
• v.6
• /
• pp.191-215
• /
• 1994

The concept of 'wilful misconduct" was initally used in article 25 of the Warsaw Convention of 1929. The concept was defined in the Hague Protocol, 1955, as having the following two differing concepts: i) "with the intent to cause damage" and ii) "recklessly and with the knowledge that damage would probably result." The concepts contained in the Hague Protocol were used in various international Conventions on carriage by sea, such as Article 2(e) and Article 3(4) of the Protocol adopted at Brussels on Feb. 23, 1968 to amend the International Convention for the Unification of Certain Rules of Law relating to Bills of Lading, signed at Brussels, Aug. 25, 1929(Hague-Visby Rules), Article 13 of the Athens Convention relating to the Carriage of Passengers and their Luggage by Sea, Dec. 13. 1974, Article 4 of the Convention on Limitation of Liability for Maritime Claims, 1976, Article 8(1) of the U.N. Convention on the Carriage of Goods by Sea, 1978(Hamburg Rules) and Article 21 (1) of the U.N. Convention on International Multimodal Transport of Goods, Geneva, 1980. The same concepts were also adopted in Article 746, 789-2(1), 789-3(2) of the Korean Maritime Commercial Law, revised in 1991. As of yet, the legal system of Korean Private Law recognizes only the concepts of "Vorsatz" and "grobe Nachlassigkeit", as is the case with German Private Law. The problem is that the concepts in the Convention do not coincide precisely with the concepts of "Vorsatz" and "grobe Nachlassigkeit". The author has conducted a comparative analysis of the treatment of the concepts of wilful misconduct and its varied interpretations, that is, "with the intent to cause damage" and "recklessly and with the knowledge that damage would probably result" in the Anglo-American law and in the continental European law in the following manner: 1. Background in which the concept of wilful misconduct was introduced in the Warsaw Convention. 2. The concept of "dol" in French private law. 3. The concepts of "Vorsatz" and "grobe Nachlassigkeit" in Korean private law. 4. Analysis of the concept of wilful misconduct in Anglo-American case law. 5. Analysis of the cases interpreting the concepts of "with intent to cause damage" and "recklessly and with knowledge that damage would probably result" in various jurisdictions. 6. The need to incorporate the concepts of "with the intent to cause damage" and "recklessly and with the knowledge that damage would probably result." 7. Faute inexcusable in French private law. Based upon the comparative analysis, the author points out the difference between the concepts of "wilful misconduct" or "with the intent to cause damage" and "Vorsatz", and between the concepts of "recklessly and with the knowledge that damage would probably result" and "grobe Nachlassigkeit" in the Convention and that of the Korean Private Law system. Additionally, the author emphasizes the importance of the unification in the interpretation of the provisions of the Conventions world wide.

• Archives of design research
• /
• v.11 no.2
• /
• pp.215-226
• /
• 1998

As late as middle of 1980s, what was referred to as new model cars consisted, on the premise of a standardized packaging layout, principally of the endeavor to transform their style images by changing little by little the form of layouts almosts similar to or with larger bodies than those of the old model ones. Afterwards even in the period of competition of engeineering and mechanical body styles for reducing fuel cost and improving comfortability in riding, the standardized packaging layout did not change visibly, simply trying to ameliorating commercialism through high output and high efficacy on the engineering part. Today the sudden prevalent motorization in every walk of life has brought about the development of the car industry, thus producing surplus supply and technical standardization. This phenomenon of technical standardization leads the concept of the renovation of car design to a way quite different from that of the past and so may be said to be confronted with an era that requires genuine-sense car design in a way. It seems that interior design plans are of much more importance than external shapes. This is because the effort for enhancing comfortability to keep car passengers' needs of transportation is one of the essences of car design. The objective of this study consists in inquiring into how to plan motorcar interior design, an essential prerequisite in determining the external or of a car, obtaining data needed via analysis of interior design plans of the car models that have won favorable criticism from consumers, thus contributing to the use of the data obtained for reference in car design activities in a genuine sense.

• Fire Science and Engineering
• /
• v.30 no.2
• /
• pp.81-86
• /
• 2016

Recently, frequent traffic congestion has occurred in domestic urban roads. As a solution for downtown traffic congestion in domestic urban roads, plans for great depth underground double-deck tunnels have been made. Great depth underground double-deck tunnels that have been planned for passenger cars, has the structure of a network type; the entry of vehicles is carried out in the underground space. In these network great depth underground double-deck tunnels, the cross section and the height of the tunnel are smaller than the general road tunnel, and the smoke of a fire will propagate faster than the evacuation of tunnel passengers by the action of the traffic-ventilation and casualties are expected. Therefore, in the present study, an attempt was made to prevent the delay system for fire smoke diffusion at the time of a fire in a domestic network great depth underground double-deck tunnel according to the area of the tunnel block during the operation of the delay system for fire smoke diffusion to analyze the effects of reducing the inflow velocity. When the area of the tunnel block was not less than 50%, the effect of reducing about 21% of the wind speed acting on the tunnel was significant. If the area is more than 50%, the diffusion rate of fire smoke was reduced by approximately 21%, which will be useful for a safe evacuation.

• Fire Science and Engineering
• /
• v.32 no.2
• /
• pp.67-72
• /
• 2018

A fire shutter is installed to prevent the movement of fire or smoke when a fire occurs inside a building. Fire shutters have access doors for passengers. On the other hand, the present fire shutter door display regulation is only required to be displayed in a different color from the surroundings. Hence, the risk of people not being able to recognize the door of the fire shutter is quite high, and the danger increases further in a smoke situation. Therefore, this study attempted to find a way to mark a fire shutter door that can be recognized even when smoke is spreading. First, a preliminary questionnaire was used to draw three factors to mark the fire shutter door (sign, door background, and edge). The experiment type was set by combining 5 colors for the three derived factors. The experiment was conducted on a total of 122 male and female participants. The results showed that a yellow background, red sign, and red edge have the highest awareness in a normal visual field without smoke. This was also the same in the field of view in the case of a fire with smoke, but the red background, yellow sign, and yellow edge were most noticeable in the case of dark smoke.

• Journal of Korean Society for Atmospheric Environment
• /
• v.26 no.5
• /
• pp.543-553
• /
• 2010

Almost five million citizens a day are using subways as a means of traffic communication in the Seoul metropolitan. As the subway system is typically a closed environment, indoor air pollution problems frequently occurs and passengers complain of mal-health impact. Especially $PM_{10}$ is well known as one of the major pollutants in subway indoor environments. The purpose of this study was to compare the indoor air quality in terms of $PM_{10}$ and to quantitatively compare its source contributions in a Seoul subway platform before and after installing platform screen doors (PSD). $PM_{10}$ samples were collected on the J station platform of Subway Line 7 in Seoul metropolitan area from Jun. 12, 2008 to Jan. 12, 2009. The samples collected on membrane filters using $PM_{10}$ mini-volume portable samplers were then analyzed for trace metals and soluble ions. A total of 18 chemical species (Ba, Mn, Cr, Cd, Si, Fe, Ni, Al, Cu, Pb, Ti, $Na^+$, $NH_4^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, and ${SO_4}^{2-}$) were analyzed by using an ICP-AES and an IC after performing proper pre-treatments of each sample filter. Based on the chemical information, positive matrix factorization (PMF) model was applied to identify the source of particulate matters. $PM_{10}$ for the station was characterized by three sources such as ferrous related source, soil and road dust related source, and fine secondary aerosol source. After installing PSD, the average $PM_{10}$ concentration was decreased by 20.5% during the study periods. Especially the contribution of the ferrous related source emitted during train service in a tunnel route was decreased from 59.1% to 43.8% since both platform and tunnel areas were completely blocked by screen doors. However, the contribution of the fine secondary aerosol source emitted from various outside combustion activities was increased from 14.8% to 29.9% presumably due to ill-managed ventilation system and confined platform space.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.13 no.2
• /
• pp.138-144
• /
• 2020

Currently, an autonomous vehicle studies are working to develop a four-level autonomous vehicle that can cope with emergencies. In order to flexibly respond to an emergency, the autonomous vehicle must move in a direction to minimize the damage, which must be conducted by judging all the states of the road, such as the surrounding pedestrians, road conditions, and surrounding vehicle conditions. Therefore, in this paper, we suggest a passenger detection and sharing system to detect the passenger situation inside the autonomous vehicle and share it with V2V to the surrounding vehicles to assist in the operation of the autonomous vehicle. Passenger detection and sharing system improve the weighting method that recognizes passengers in the current vehicle to identify the passenger's position accurately inside the vehicle, and shares the passenger's position of each vehicle with other vehicles around it in case of emergency. So, it can help determine the driving of a vehicle. As a result of the experiment, the body pressure sensor applied to the passenger recognition sub-module showed about 8% higher accuracy than the conventional resonant sensor and about 17% higher than the piezoelectric sensor.