• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.519-521
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• 2005

In recent years, LiDAR(Light Detection and Ranging) data has been widely used to prepare digital elevation models(DEMs) with the high spatial resolution of centi-meters. This paper investigated possible applications of LiDAR-derived DEMs in surface hydrology modeling, such as characterizing flow direction, identifying sub-basins in a watershed, and calculating variables like upstream contribution area. The results were compared to the results of the DEMs from conventional topographic maps.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10c
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• pp.581-585
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• 2006

네트워크 환경의 발달과 더불어 DDoS 공격이나 웜 공격이 증대되고 있다. 다양한 공격의 증가뿐만 아니라 최근에는 공격이 발생하면 급속히 피해가 확산된다. 피해 속도가 빨라지는 이유 중의 하나는 피해 시스템이 공격자가 되기 때문이다. 그러나 만약 피해 시스템이 또 다른 공격 시스템이 되는 것을 차단할 수 있다면, 공격이 확산되는 속도를 늦출 수 있다. 본 논문에서는 감염된 시스템이 비정상적으로 많은 트래픽을 발생시키는 것을 탐지하기 위하여 특정 주소를 갖는 시스템으로 일정 기간 동안 들어오고 나간 인바운드 패킷과 아웃바운드 패킷의 양을 비율로 나타내어 트래픽 흐름을 분석한다. 그리고 B-클래스 네트워크에서 추출한 트래픽 샘플데이터를 이용하여 트래픽 흐름을 분석하여 감염된 시스템을 탐지할 수 있음을 보인다.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.93-96
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• 2017

Ephedra alkaloids, (-)-ephedrine, (+)-pseudoephedrine, (-)-N-methylephedrine, (+)-N-methylpseudoephedrine, (-)-norephedrine and (+)-norpseudoephedrine, from ephedra herb are sympathomimetic agonists causing an increase of metabolism, blood pressure and perspiration. In this study, we developed the validation method of (+)-pseudoephedrine and (-)-ephedrine, two major ephedra alkaloids in Ephedra spp., by high-performance liquid chromatography-ultraviolet spectrometer (HPLC-UV). HPLC analysis was performed using a HECTOR-M C18 column operating at $35^{\circ}C$, and UV detection at 215nm. The mobile phase used a gradient flow with 25 mM SDS in water (A) and acetonitrile (B).

• Journal of the Korean Society of Visualization
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• v.14 no.1
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• pp.27-32
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• 2016

The reduction of $CO_2$ emissions has been a key target in the Marine Industry since the IMO's Marine Environment Protection Committee published its findings in 2009. The representative emission index is termed as the EEDI (Energy Efficiency Design Index) for the new ships. Among various flow control techniques ever proposed, the air lubrication method is the one of most promising one in terms of practical applicability. The present study examines the basic characteristics of the flat plate test with intention of applying the air lubrication technology to the reduction of the resistance of a ship. Image analysis technique is proposed as a tool to quantify the effectiveness of the air lubrication method.

• Journal of Pharmaceutical Investigation
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• v.37 no.3
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• pp.187-192
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• 2007

A reversed phase HPLC analysis of atorvastatin (AS) standard solution was performed using diclofenac (DF) as internal standard. Column oven temperature, flow rate and the composition of the mobile phase were varied in order to determine a practical system setup using a C18 column and UV detector. Two C18 columns of different length were compared regarding their influence on the AS peak shape. Based on these preliminary experiments a validation study was performed utilizing a C18 column at $62^{\circ}C$ with a mobile phase consisting of sodium phosphate buffer (0.05 M, pH 4.0), methanol and acetonitrile (40:50:10, v/v/v). The detection limit for AS was $0.1{\mu}g/ml$ and inter- and intra-day calibration curves were linear over a concentration range of $0.2-50{\mu}g/ml$. Accuracy and precision were satisfactory in the AS concentration range of $0.5-50{\mu}g/ml$.

• Analytical Science and Technology
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• v.6 no.5
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• pp.509-514
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• 1993

Benomyl, topsin-M and thiram been known as one of the seed disinfectant. For these studies benomyl, topsin-M and thiram simultaneously had been analyzed by high performance liquid chromatographic method using ODS cartridge, benomyl, topsin-M and thiram was chromatographed using an ODS column and eluent 40% Acetonitrile at a flow rate of 1ml/min. The UV Detector responses at 276nm.

• International Journal of Contents
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• v.1 no.1
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• pp.1-5
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• 2005

This paper presents the development and application of electrical resistance imaging techniques for the visualization of two-phase flow fields. Two algorithms, the so-called the mesh grouping and the boundary estimation, are described for potential applications of electrical resistance tomography (ERT) and results from extensive numerical simulations are also presented. In the electrical resistance imaging for two-phase flows, numerical meshes fairly belonging to each phase can be grouped to improve the reconstruction performance. In many cases, the detection of phase boundary is a key subject and a mathematical model to estimate phase boundary can be formulated in a different manner. Our results indicated that the mesh grouping algorithm is effective to enhance computational performance and image quality, and boundary estimation algorithm to determine the phase boundary directly.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.9
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• pp.911-915
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• 2008

Software birthmark is the inherent characteristics that can identify a program. In this paper, we propose a Java class theft detection technique based on static API traces of class files. We utilize control flow analysis to increase resilience, and we apply the semi-global alignment trace comparison algorithm to increase credibility. The credibility and resilience experiments for XML parsers show that our birthmark is more efficient than existing birthmarks.

• Journal of Korea Multimedia Society
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• v.16 no.12
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• pp.1439-1445
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• 2013

We present a Taekwondo training system using a hybrid sensing technique of a body sensor and a visual sensor. Using a body sensor (accelerometer), rotational and inertial motion data are captured which are important for Taekwondo motion detection and evaluation. A visual sensor (camera) captures and records the sequential images of the performance. Motion chunk is proposed to structuralize Taekwondo motions and design HMM (Hidden Markov Model) for motion recognition. Trainees can evaluates their trial motions numerically by computing the distance to the standard motion performed by a trainer. For motion training video, the real-time video images captured by a camera is overlayed with a visualized body sensor data so that users can see how the rotational and inertial motion data flow.

• Journal of Information Processing Systems
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• v.6 no.3
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• pp.375-384
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• 2010

Trajectory modeling is foundational for 4D-Route modeling, conflict detection and air traffic flow management. This paper proposes a novel algorithm based Vincenty's fomulas for trajectory calculation, combined with the Dijkstra algorithm and Vincenty's formulas. Using flight plan simulations our experimental results show that our method of En-route trajectory calculation exhibits much improved performance in accuracy.