• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.495-502
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• 2007

Species biotic index (SBI), based on a fish assemblage, was applied to a stream assessment using long-term ecological fish data set (1996 to 2001) in Boryong dam area, which is located in the mainstream of Ungchun Stream of Chungnam province, Korea. According to the methods of Hilsenhoff (1988), the scores of tolerance guild assigned 10 classes to each species by its habitat and feeding guild, but modified current 7 criteria to 5 scoring standards due to unclear borderline among species. Relative abundance in the species number of upper stream guilds was only 7% of the total, whereas the abundance in the species number of middle to downstream upper stream guilds was 64%. Mean SBI, based on dataset in Site 1 during 1995-2001 averaged 5.10, which was judged as a "good" condition by the rank criteria of SBI. Before the dam construction, mean SBI in the Site 1 was 4.61, indicating a "good" condition, but after the dam construction, mean SBI was 5.60, indicating a "fair" condition. Trajectory analysis in the Site 1 showed significantly (One-way ANOVA, $F_{6,21}=3.26$, p=0.02) different among years, reflecting the changes of fish composition and population density by the dam construction, whereas Site 2 showed no significant changes ($F_{6,21}=1.00$, P =0.45) difference among years. Mean SBI prior to the dam construction in the Site 3 was 4.52 but after the construction, the value was 6.30, indicating a distinct difference between the pre- and post-dam construction. Trajectory analysis at the Site 3 supported this fact: Values of SBI showed significantly ($F_{6,21}$=14.37, p<0.01) different. Mean SBI was 4.67 in the Site 4, indicating a "good" condition in the health and the health rank was same as the sampling sites 1, 2, and 4. Trajectory in the Site 4 showed no significant ($F_{6,21}=2.35$, p=0.07) difference among the years. Overall, our trajectory analysis indicated that three of four sampling sites (sites 1, 3, 4) showed significant decreases (n=7, p<0.05) and that the proportions of sensitive species declined evidently in the sites 1 and 2 and the tolerant species increased in the dam sites. Our outcomes may be used as a key data for diagnosis of the long-term ecological impact in the future in the watershed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.593-596
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• 2018

The speed of vehicles has remained a significant factor that influences the severity of accidents and traffic accident rate in many parts of the world including South Korea. This behavior where drivers drive at speeds which exceed a posted safe threshold is known as 'speeding'. Over the past twenty years, the Korean National Police Agency (NPA) has become aware of an increased frequency of drivers who are speeding. Therefore, fixed-type ASE systems [1] have been installed on hazardous road sections of many highways. These system monitor vehicle speeds using a camera. However, the use of ASE systems has changed the behavior of the drivers. Specifically, drivers reduce speed or avoid the route where the cameras are mounted. It is not practical to install cameras at every possible location. Therefore, it is challenging to thoroughly explore the location where speeding occurs. In view of these problems, the author of this paper designed and implemented a prototype visualization system in which point and color are used to show vehicle location and associated over-speed information. All of this information was used to create a comprehensive visualization application to show information about vehicle driving. In this paper, we present an approach detecting vehicles moving at speeds which exceed a threshold and visualizing the points those violations occur on a map. This was done using vehicle trajectory data collected in Daegu city. We propose steps for exploring the data collected from those sensors. The resulting mapping has two layers. The first layer contains the dynamic vehicle trajectory data. The second underlying layer contains the static road networks. This allows comparing the speed of vehicles on roads with the known maximum safe speed of those roads, and presents the results with a visualization tool. We also compared data about people who drive over threshold safe speeds on each road on days and weekends based on vehicle trajectories. Finally, our study suggests improved times and locations where law enforcement should use monitoring with speed cameras, and where they should be stricter with traffic law enforcement. We learned that people will drive over the speed limit at midnight more than 1.9 times as often when compared with rush hour traffic at 8 o'clock in the morning, and 4.5 times as often when compared with traffic at 7 o'clock in the evening. Our study can benefit the government by helping them select better locations for installation of speed cameras. This would ultimately reduce police labor in traffic speed enforcement, and also has the potential to improve traffic safety in Daegu city.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1319-1326
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• 2011

We have investigated the characteristics of the electron beam (e-beam) in the miniaturized free electron laser module by using the commercial 3D simulation tool OPERA. The e-beam was made parallel before entering the slit-type wiggler by the negative bias applied to the central electrode of the electron lens. With respect to the different structures of the wiggler, we obtained the inner distributions of the electrical potential and the electric field, which was, in turn, used to calculate the trajectory of the e-beam in the wiggler.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.52-62
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• 2013

In order to obtain the relation between the cutting force and the process parameters in the chamfering process for the gear of a gear shaft, analysis of the process was performed with a simplified model instead of considering the whole actual 3-dimensional cutting situation produced between cutting tool and gear. The model divided the actual situation into the accumulation of hundreds of 2-dimensional layers with a small thickness in the direction of the height of gear and derived cutting force at a cutting position by accumulating each cutting force calculated in a layer. With proposed method to analyze the cutting forces in the chamfering process, it was revealed that the cutting position and size were exactly searched to calculate the cutting force in each layer. The total cutting force was the highest in the corner where the cutter encountered the gear first during the relative motion between them. The cutting forces were changed in proportion to the cutting parameters such as feed rate and trajectory.

• Journal of Korean Academy of Nursing
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• v.32 no.4
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• pp.482-491
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• 2002

This study aimed to identify the change patterns of fatigue and quality of life during consecutive chemotherapies and to determine the relationship of these two variables. Method: Stomach cancer patients receiving chemotherapy were recruited from a university hospital in Seoul. Each chemotherapy, subjects were asked to respond to the questionnaires regarding their fatigue and quality of life. The number of subjects who completed 4 cycles and over was 11. Fatigue was measured with Lee's tool(1999). Quality of life was measured with a tool revised by the author based on Padilla et al(1983). Result: Most patients were in 1st stage(5 patients) or 3rd stage(5 patients). Fatigue was revealed at its highest level in the 3rd or 4th chemotherapy and at its lowest level in the 1st or 6th chemotherapy. A quality of life appeared at its highest level in the 5th or 6th chemotherapy and the lowest level in 3rd or 4th chemotherapy. Conclusion: Among 6 cycles of chemotherapy, in 3-4th chemotherapy the fatigue was the highest and the quality of life were the lowest. Many patients decided to stop treatment at the same period. Therefore we can recognize cancer patients receiving chemo- therapy are in the highest risk at the time of the 3-4 th chemotherapy.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.2
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• pp.112-117
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• 2016

In the construction industry, concrete polishing is used to grind and rub the surface of concrete grounds with polishing machines to increase the strength of the concrete after deposition. Polishing is performed manually in spite of the generation of dust and the requirement of frequent replacements of the polishing pad. The concrete polishing robot developed in this research is a novel polishing automation system for preventing the workers from being exposed to poor working environments. This robot is able to change multiple polishing tools automatically; however, the workers can conveniently replace the worn-out polishing pads with new ones. The mobile platform of the polishing robot employs omnidirectional wheels to enable a flexible motion even in small and complicated workspaces. To evaluate the performance of the developed concrete polishing robot, extensive experiments including square trajectory tracking, automatic tool changing, actual polishing, and path generation simulation were performed.

• Korean Journal of Optics and Photonics
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• v.14 no.2
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• pp.194-199
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• 2003

The analysis of operation characteristics of a miniaturized electrostatic electron lens system called an Einzel lens was performed using a simulation tool of FCM method. The potential distributions of Einzel lenses operated both in retarding and accelerating modes show similar features. But the electric fields determined from the potential distributions show opposite directions, which results in different features in the electron beam trajectory in each mode of operation. For the same working distance, focusing voltage in the accelerating mode is higher than that in the retarding mode.

• Journal of KIEE
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• v.11 no.1
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• pp.55-61
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• 2001

SIME(Single Machine Equivalent) method has been recognized as a useful tool to determine transient stability of power system. In this paper, SIME method is used to develop the KEPCO transient stability assessment (TSA) tool. A new screening algorithm that can be generators are identified by a new index in the early stage of the time domain simulation. Thus, computational time require to find OMIB(One Machine Infinite Bus) can be reduced significantly. Second, clustering critical machines can be performed even in very stable cases. It enables to be avoid extra calculation of time trajectory that is needed in SIME for classifying the stable cases. This algorithm is applied to the fast TSA of the KEPCO system in the year of 2010.

• Journal of Daesoon Thought and the Religions of East Asia
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• v.2 no.1
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• pp.133-155
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• 2022

Throughout the Chinese sphere, that is, in the People's Republic of China and Taiwan, tea houses, tea stores, and tea meditation groups often without a particular religious orientation have appeared in the past decades. Tea lovers groups with various philosophical discussions appear throughout cyberspace, where people show their appreciation for tea as a drinkable delicious product and a spiritual tool. The question to be asked here is whether it should be recognized as a religious or spiritual practice agent in and of itself? Should we then talk about the present-day movement of teaism? If we do recognize this as a spiritual phenomenon, should it then be labeled as a New Religious Movement? The trajectory of tea in China is intrinsically connected to religious traditions. This connection is historical, yet it plays a part in the contemporary religious and spiritual sphere. The article explores the continuation and developments of tea culture in the context of the religious sphere of China, looking at practices connected to tea of communities, religious organizations, and individuals. The author explores how tea drinking, commercializing and tea related practices intersect with politics, materiality, and spirituality in contemporary society. In this context it is then argued that tea is a cultural element, religious self-refinement tool, and an active material agent with social-political capacities. The study includes historical narratives, ethnographic data, and literary sources about tea, making up a genealogy of tea which encompasses ritualistic aspects, economic aspects, and power relations related to tea in Chinese society.

• Journal of the Korea Safety Management & Science
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• v.6 no.1
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• pp.283-300
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• 2004

This paper describes the NC simulator system for Wire-cut electrodischarge machining. Electrodischarge Wire-cut machining is applicable to all materials including metals, alloys, and most carbides. Although CAM system generate the NC code considering electrodischarge conditions, incorrect Wire-cut tool path bring about fatal results. The simplest way of simulating a EDM process is to display the trajectory of Wire-cutter location by line segments. With this kind of simulation, the programmer can get a general idea about whether the wire is moving as planned but cannot locate gouging or excess material because only the wire location will be seen, not the changes in the workpiece as it is machined. The ideal way of simulating the EDM process is to display the solid model of the workpiece as it is machined. Therefore we propose the ideal NC simulator system for Wire-cut EDM.