• Journal of Korean Society of Transportation
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• v.23 no.1
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• pp.9-20
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• 2005

Accident type and/or factor identification is important in accident reduction planning. The aim of this paper is to apply the hierarchical approach with binomial distribution and logistic regression analysis to find out types and factors, respectively. Based on 2001 Suwon city black spot data, a binomial distribution modeling approach has been applied to diagnose the black spots, with the help of safety performance modeling approach has been applied to diagnose the black spots, with the help of safety performance function. Then, the logistic regression analysis has been employed to identify the critical factors. Some accident remedies are also reviewed in the light of the model outcomes. The proposed research framework sheds light on a different accident related research and can also be successfully applied to similar studies and sites.

• School Mathematics
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• v.9 no.2
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• pp.223-240
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• 2007

The purpose of this study was to investigate the degree to which the middle school mathematics curriculum matched the item difficulty levels of representative mathematics items. The items used in this study were developed for the National Assessment of Educational Achievement. Ranks for difficulty values of the 60 multiple-choice item were calculated via both Classical Test Theory and Item Response Theory and correlated with the rank order of the mathematics content and cognitive domains sequence. There are six content domains; number and operation, algebra, measurement, figure, pattern and function, and probability and statistics. The cognitive domains include computation, understanding, reasoning and problem-solving. Results suggest a congruence between cognitive domain's sequence and item difficulty levels of items based on that sequence. This finding indicates that the linear or hierarchical assumptions concerning the sequence appears to be reasonable. The characteristics of items that were exceptions to this trend were addressed.

• Journal of Korean Society of Transportation
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• v.31 no.4
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• pp.85-94
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• 2013

The Continuous Risk Profile (CRP) has been well known to be the most accurate and efficient among existing network screening methods. However, the classical CRP uses safety performance functions (SPFs) which require a huge investment to construct a database system. This study aims to suggest a new CRP method using average crash frequencies of homogeneous groups, instead of SPFs, as rescaling factors. Hierarchical clustering analysis is performed to classify freeway segments into homogeneous groups based on the data of AADT and number of lanes. Using the data from I-880 in California, the proposed method is compared to other several network screening methods. The results show that the proposed method decrease false positive rates while it does not produce any false negatives. The method developed in this study can be easily applied to screen freeway networks without any additional complex database systems, and contribute to the improvement of freeway safety management systems.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.5_6
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• pp.360-370
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• 2004

Adaptive mesh refinement(AMR) is one of the popular computational simulation techniques used in various scientific and engineering fields. Although AMR data is organized in a hierarchical multi-resolution data structure, traditional volume visualization algorithms such as ray-casting and splatting cannot handle the form without converting it to a sophisticated data structure. In this paper, we present a hierarchical multi-resolution splatting technique using k-d trees and octrees for AMR data that is suitable for implementation on the latest consumer PC graphics hardware. We describe a graphical user interface to set transfer function and viewing / rendering parameters interactively. Experimental results obtained on a general purpose PC equipped with an nVIDIA GeForce3 card are presented to demonstrate that the proposed techniques can interactively render AMR data(over 20 frames per second). Our scheme can easily be applied to parallel rendering of time-varying AMR data.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1291-1300
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• 2004

Baicalin, a biologically active flavonoid form the roots of Scutallaria baicalensis (Skullcap), have been reported to not only function as anti-oxidants but also cause anticancer effect. We investigated the mechanism of baicalin-induced cytotoxicity and the macro scale gene expression analysis in leukemia cell line, HL-60 cells. Baicalin (10 μM) were used to treat the cells for 6h, 12h, 24h, 48h and 72h. In a human cDNAchip study of 65,000 genes evaluated 6, 12, 24, 48. 72 hours after treated with Baicalin in HL-60 cells. Hierarchical cluster against the genes which showed expression changes by more than two fold. One hundred one genes were grouped into 6 clusters according to their profile of expression by a hierarchical clustering algorithm. For genes differentially expressed in response to baicalin treatment, we tested functional classes based on Gene Ontology (GO) terms. This study provides the most comprehensive available survey of gene expression changes in response to baicalin treatment in HL-60 cell line.

• Journal of Korea Multimedia Society
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• v.2 no.3
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• pp.252-264
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• 1999

The key characteristic of video data is its spatial/temporal relationships. In this paper, we propose an content based video retrieval system based on hierarchical data structure for specifying the temporal semantics of video data. In this system, video data's hierarchical structure temporal relationship, inter video object temporal relationship, and moving video object temporal relationship can be represented. We also implemented these video data's temporal relationship into an object-relational database management system using inheritance, encapsulation function overloading, etc. So more extended and richer temporal functions can be used to support a broad range of temporal queries.

• Journal of Electrical Engineering and Technology
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• v.4 no.4
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• pp.429-437
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• 2009

This paper proposes a hybrid voltage controller based on a hierarchical control structure for implementation in the Jeju power system. The hybrid voltage controller utilizes the coordination of various reactive power devices such as generators, switched shunt devices and LTC to regulate the pilot voltage of an area or zone. The reactive power source can be classified into two groups based on action characteristics, namely continuous and discrete. The controller, which regulates the pilot bus voltage, reflects these characteristics in the coordination of the two types of reactive power source. However, the continuous type source like generators is a more important source than the discrete type for an emergency state such as a voltage collapse, thereby requiring a more reactive power reserve of the continuous type to be utilized in the coordination in order to regulate the pilot bus voltage. Results show that the hybrid controller, when compared to conventional methods, has a considerable improvement in performance when adopted to control the pilot bus voltage of the Jeju island system.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.350-355
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• 2009

Arachidonic acid (AA) is a polyunsaturated fatty acid that is a normal constituent of membrane lipids in animal cells. In addition to its role as a precursor of prostaglandins, AA itself may play an important role in the regulation of cell function. The effect of AA on functions of granulosa cells was investigated in pre-hierarchical small yellow follicles of laying hens. Immuno-cytochemical staining showed that AA ($10^{-7}-10^{-5}$ M) increased the expression of the extracellular matrix glycoprotein laminin, gap junction connexin 43 and protein kinase C (PKC). Therefore, mediated by the PKC signal pathway, AA may regulate the intercellular communication of granulosa cells and follicular development by increasing the expression of laminin and connexin.

• International Journal of Contents
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• v.3 no.2
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• pp.1-5
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• 2007

This paper proposes a technique for principal component analysis (PCA) to raise the recognition rate of a front face in a low dimension by hierarchical image and parallel processing structure. The conventional PCA shows a recognition rate of less than 50% in a low dimension (dimensions 1 to 6) when used for facial recognition. In this paper, a face is formed as images of 3 fixed-size levels: the 1st being a region around the nose, the 2nd level a region including the eyes, nose, and mouth, and the 3rd level image is the whole face. PCA of the 3-level images is treated by parallel processing structure, and finally their similarities are combined for high recognition rate in a low dimension. The proposed method under went experimental feasibility study with ORL face database for evaluation of the face recognition function. The experimental demonstration has been done by PCA and the proposed method according to each level. The proposed method showed high recognition of over 50% from dimensions 1 to 6.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.670-675
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• 1994

Yhis paper describes a fault diagnosis simulation of the Real-Time Multiple Fault Dignosis System (RTMFDS) for forcasting faults in a system and deciding current machine state from signal information. Comparing with other diagnosis system for single fault,the system developed deals with multiple fault diagnosis,comprising two main parts. One is a remotesignal generating and transimission terminal and the other is a host system for fault diagnosis. Signal generator generate the random fault signal and the image information, and send this information to host. Host consists of various modules and agents such as Signal Processing Module(SPM) for sinal preprocessing, Performence Monotoring Module(PMM) for subsystem performance monitoring, Trigger Module(TM) for multi-triggering subsystem fault diagnosis, Subsystem Fault Diagnosis Agent(SFDA) for receiving trigger signal, formulating subsystem fault D\ulcornerB and initiating diagnosis, Fault Diagnosis Module(FDM) for simulating component fault with Hierarchical Artificial Neural Network (HANN), numerical models and Hofield network,Result Agent(RA) for receiving simulation result and sending to Treatment solver and Graphic Agent(GA). Each agent represents a separate process in UNIX operating system, information exchange and cooperation between agents was doen by IPC(Inter Process Communication : message queue, semaphore, signal, pipe). Numerical models are used to deseribe structure, function and behavior of total system, subsystems and their components. Hierarchical data structure for diagnosing the fault system is implemented by HANN. Signal generation and transmittion was performed on PC. As a host, SUN workstation with X-Windows(Motif)is used for graphic representation.