• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.145-154
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• 2004

The growing demand for customer-responsive, made-to-order manufacturing is stimulating the need for improved dynamic decision-making processes in commercial fleet operations. Moreover, the rapid growth of electronic commerce through the internet is also requiring advanced and precise real-time operation of vehicle fleets. Accompanying these demand side developments/pressures, the growing availability of technologies such as AVL(Automatic Vehicle Location) systems and continuous two-way communication devices is driving developments on the supply side. These technologies enable the dispatcher to identify the current location of trucks and to communicate with drivers in real time affording the carrier fleet dispatcher the opportunity to dynamically respond to changes in demand, driver and vehicle availability, as well as traffic network conditions. This research investigates key aspects of real time dynamic routing and scheduling problems in fleet operation particularly in a truckload pickup-and-delivery problem under various settings, in which information of stochastic demands is revealed on a continuous basis, i.e., as the scheduled routes are executed. The most promising solution strategies for dealing with this real-time problem are analyzed and integrated. Furthermore, this research develops. analyzes, and implements hybrid algorithms for solving them, which combine fast local heuristic approach with an optimization-based approach. In addition, various partitioning algorithms being able to deal with large fleet of vehicles are developed based on 'divided & conquer' technique. Simulation experiments are developed and conducted to evaluate the performance of these algorithms.

• Journal of Korean Society of Transportation
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• v.33 no.2
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• pp.192-203
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• 2015

Pedestrians not only walk along pedestrian pathways, but also choose unusual routes such as passing through buildings or crossing large scale open spaces. This study defines these unusual paths as social path, and includes them into one of the pedestrian road categories. Previous pedestrian accessibility and route choice studies could not evaluate correctly the space connectivity or optimal route because the social path was not considered properly. Therefore, this study analyzes the effectiveness of the social path in view of space connectivity focused on Coex and Seoul stations in Seoul, which are representative transit oriented development(TOD) areas. Global integration, which is widely used in network analysis, is selected (as performance index) to identify the space hierarchy and define new pedestrian links. The study results show that the network connectivity is improved especially in the main streets and social paths. This study demonstrated that the social path should be considered in finding the pedestrian optimal route from the practical perspective.

• Development and Reproduction
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• v.13 no.2
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• pp.79-87
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• 2009

Due to its well-known function in parturition and milk ejection, oxytocin (OT) has been considered as a 'female neurohypophyseal hormone'. Recent studies, however, clearly indicate that OT has some local roles in male reproduction via both central and peripheral routes. In experimental rodents, OT is released within distinct brain regions in response to social stimuli, and the brain OT receptor (OTR) mediated actions were strongly involved in the regulation of a variety of male behaviors such as mating-associated behaviors. In particular, OT and/or OTR knockout mice provide important clues about the molecular regulatory mechanism of the socio-sexual behaviors. Several lines of evidence also show that OT is synthesized within rodents testis, epididymis and prostate, and the presence of OTRs in these organs. In rodent testes, OT might have a role in the modulation of steroidogenesis via stimulation of the conversion of testosterone (T) to dihydrotestosterone (DHT) by 5alpha-reductase. Similar effects of OT on this androgen conversion were observed in epididymis and prostate suggesting the OT's modulatory role, such as contractility induction, in these androgen-dependent organs. In this context, further investigations on the OT's role in male CNS and reproductive organs are likely to provide better understanding on the complex socio-sexual behaviors and a platform for development of therapeutics to treat some psychological and/or andrological problems.

• Asian Journal of Atmospheric Environment
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• v.11 no.2
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• pp.114-121
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• 2017

Real-time monitoring of hourly concentrations of atmospheric Radon-222 ($^{222}Rn$, radon) and some gaseous pollutants ($SO_2$, CO, $O_3$) was performed throughout 2013-2014 at Gosan station of Jeju Island, one of the cleanest regions in Korea, in order to characterize their background levels and temporal variation trend. The hourly mean concentrations of radon and three gaseous pollutants ($SO_2$, CO, $O_3$) over the study period were $2216{\pm}1100mBq/m^3$, $0.6{\pm}0.7ppb$, $211.6{\pm}102.0ppb$, and $43.0{\pm}17.0ppb$, respectively. The seasonal order of radon concentrations was as fall ($2644mBq/m^3$)$${\sim_\sim}$$winter ($2612mBq/m^3$)>spring ($2022mBq/m^3$)>summer ($1666mBq/m^3$). The concentrations of $SO_2$ and CO showed similar patterns with those of radon as high in winter and low in summer, whereas the $O_3$ concentrations had a bit different trend. Based on cluster analyses of air mass back trajectories, the air mass frequencies originating from Chinese continent, North Pacific Ocean, and the Korean Peninsula routes were 30, 18, and 52%, respectively. When the air masses were moved from Chinese continent to Jeju Island, the concentrations of radon and gaseous pollutants ($SO_2$, CO, $O_3$) were relatively high: $2584mBq/m^3$, 0.76 ppb, 225.8 ppb, and 46.4 ppb. On the other hand, when the air masses were moved from North Pacific Ocean, their concentrations were much low as $1282mBq/m^3$, 0.24 ppb, 166.1 ppb, and 32.5 ppb, respectively.

• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.1-14
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• 2017

This study aims to understand the influences that emotional and behavioral problems, relationships with parents, peer groups and teachers have on school refusal tendency and their routes targeting for 546 students of the 1st and 2nd grades in the boys' and girls' middle schools in G city and to conduct a path analysis by using Pearson's product-moment correlation and LISREL program. The results are the followings: First, significant correlation is shown in the all relationships, excluding the external problems out of emotional and behavioral problems, social support factor out of teachers-related variables, negative support factor out of parents-related variables. Second, emotional and behavioral problems have highly direct influence on school refusal tendency and relationship with parents without any meditator effect and has indirect influence on relationships with peer groups and teachers without having statistically significant and direct influence. Also, relationship with peer groups has statistically significant and negative effect on school refusal tendency without having statistically significant and direct influence, teachers relationship has statistically significant and direct effect on school refusal tendency and relationship with parents has indirect influence on school refusal tendency through relationship with peer groups and teachers relationship without having statistically significant and direct effect.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.25-43
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• 2016

This research was completed to provide fundamental data regarding the guidelines to installing and managing utility facilities & structures in wetland protected area to advance the functions and sustainable use of ecology services by preserving the ecology within wetland protected area. There were 5 on-site researching areas that were used as the main subject with these areas chosen and considered from 21 inland wetlands that have been designated and are being managed from the Ministry of Environment and by their designated dates as a wetland protected area. The utility facilities in these wetland areas were categorized by their types and a detailed on-site investigation was proceeded with investigation items chosen whereas these facilities are working by their roles from their location, size, used materials, types, information contents and etc., The results showed that regarding informational structures, several locations of information boards were distanced from the main exploring routes which did not consider the visitor's eye level which had their readability dropped and by sunlight, time lapse and water penetration, many information boards were damaged or corrupted so that it was hard to confirm the information noticed or understanding an image. Insufficient observation and educational structures were installed that considered the ecological characteristics of wild animals and their living conditions. Regarding convenience facilities, there were parking lots that were installed on the fore-land and to decrease non-point solution sources, some parking lots needed to be located in protected lowlands while some facilities' shape and colors did not harmonize with their natural surroundings, creating a sense of awareness, which will need some more consideration. As for safety facilities, they were very insufficient compared to other facilities. This means that additional safety structures are needed so that related personnel can be aware of where a visitor is located when an accident occurs. Protectional facilities strongly needed new structures and a management system to cut off entrances and do surveillance so that visitors do not go into areas outside of the managed areas and bring damages to restricted locations. Research labs needed to expand the use of automatic weather systems and water gauge equipments to build fundamental data regarding floodgates that are intimated to the forming of wetlands. Sensor cameras and other types of monitoring systems are needed to monitor the majority types of animals living in the wetlands as well.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.6
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• pp.1-19
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• 2017

This study set out to identify problems with amphibian habitation by the wetland types and improve their habitation environment in urban forest wetlands, thus creating a habitat for amphibians. Study site include forest swamps in Jatjul Park as well as Yeoji neighborhood Park in Guro-gu, and in Choansan neighborhood Park in Dobong-gu. The forest swamp in Jatjul Park gets its water from Mt. Maebong and it is a former escalated farmland-turned wetland. The swamp area is $2,500m^2$, a forest zone and a landscape planting site are 83.27% and 6.70% each. Target species Seoul pond frogs are inseparable from rice fields because they live in a short radius of and lay eggs in or near paddy fields, and Rana nigromaculata have similarities with Rana plancyi chosenica in choosing their habitats. There was need for paths that would lead to other paths so amphibians would spread to other parts of the forest and for measures to secure open water. Modifying a variety of routes for water, human and animals along with building a buffer to keep the core habitation zones were required. The forest swamp in Yeonji neighborhood Park used to be a water reservoir on the foot of Mt. Gunji. The swamp area is $1,980m^2$, a forest zone and farmland account for 80.61% and 4.88% each. Non-point pollutants from upstream along run into the subject forest marsh, bare ground on the around swamp and steep stone embankments obstructed amphibians. Target species was Bufo gargarizans that live in forests and edges of hills and spawn in deep water. The forest swamp in Choansan neighborhood Park gets its water from Mt. Choan and it is close to its water source that it is a mountain stream forest wetland. The basin and the swamp are $35,240m^2$ and $250m^2$ in size respectively. A forest zone accounts for 90.20%, high stone embankments laid in refurbishing the valley obstruct amphibians and there is water shortage in times of droughts. Target species were Rana coreana, Rana dybowskii and Hynobius leechii that live in mountain valleys, streams and wetlands and lay eggs in forest marshes and rocks in valleys. Looking into the three swamps of amphibian habitation, I came to conclusions that those wetlands were suitable for their amphibians but man-made facilities blocked their corridors leading to other corridors and even killed off target species in some parts of those swamps by destroying those parts. Amphibians live in water, on ground and underground at different stages of life. Hence, we should take this fact into consideration when planning their habitats and design core habitation zones, buffers zone and use zones accordingly. Buffer zones ought to be between core habitation zones and surrounding trees. Aiming at protecting core habitation zones, buffers should be in harmony with habitation zones. Use zones should be minimized in size and not in direct contact with core habitation zones.

• Journal of Intelligence and Information Systems
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• v.11 no.3
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• pp.25-43
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• 2005

In modern automated container terminals, automated guided vehicle (AGV) systems are considered a viable option for the horizontal tansportation of containers between the stacking yard and the quayside cranes. AGVs in a container terminal move rather freely and do not follow fixed guide paths. For an efficient operation of such AGVs, however, a sophisticated traffic management system is required. Although the flexible routing scheme allows us to find the shortest possible routes for each of the AGVs, it may incur many coincidental encounters and path intersections of the AGVs, leading to collisions or deadlocks. However, the computational cost of perfect prediction and avoidance of deadlocks is prohibitively expensive for a real time application. In this paper, we propose a traffic control method that predicts and avoids some simple, but at the same time the most frequently occurring, cases of deadlocks between two AGVs. More complicated deadlock situations are not predicted ahead of time but detected and resolved after they occur. Our method is computationally cheap and readily applicable to real time applications. The efficiency and effectiveness of our proposed methods have been validated by simulation.

• Journal of KIISE:Information Networking
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• v.36 no.4
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• pp.286-296
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• 2009

A major challenge in next generation optical Internet (NGOI) networks based on dense-wavelength division multiplexing (DWDM) is the provision of guaranteed quality-of-service (QoS) for a wide variety of multimedia applications. One of the critical issues in NGOI is the routing and wavelength assignment problem that is embossed as very important and plays a key role in improving the global efficiency for capacity utilization. But the previous researches had the delay problem, and the path routed by higher priority nodes may be congested and interfere with potential future multicast session requests. To overcome these problems, in this research we suggest a Priority-based Minimum Interference Path Multicast Routing (PMIPMR) algorithm, a new routing algorithm which finds alternative routes based on node priorities and Virtual Source (VS) nodes that has both splitting and wavelength conversion, and then chooses a path that does not interfere with potential future multicast session requests when congestions occur in the network. The PMIPMR algorithm reduces blocking rate significantly and increases the wavelength utilization by avoiding congestion in future multicast session requests.

• KIISE Transactions on Computing Practices
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• v.20 no.12
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• pp.652-657
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• 2014

Given a starting point, destination point and various Points Of Interest (POIs), which contain a full or partial order, for a user to visit we wish to create, a sequenced route from the starting point to the destination point that includes one member of each POI type in a particular order. This paper proposes a method for finding the approximate shortest route between the start point, destination point and one member of each POI type. There are currently two algorithms that perform this task but they both have weaknesses. One of the algorithms only considers the distance between the visited POI (or starting point) and POI to visit next. The other algorithm chooses candidate points near the straight-line distance between the start point and destination but does not consider the order of visits on the corresponding network path. This paper outlines an algorithm that chooses the candidate points that are nearer to the network path between the start point and destination using network search. The algorithm looks for routes using the candidate points and finds the approximate shortest route by assigning an adaptive priority to the route that visits more POIs in a short amount of time.