• Analytical Science and Technology
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• v.14 no.2
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• pp.180-190
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• 2001

Oder-active compounds are complex in a sample. These compounds are usually analyzed by GC or GC/MSD while such analytical measurement can quantify specific volatile organic compounds, it has limitations in identifying odor-active compounds. To resolve this problem, GC-Sniffing or GC-Olfactometry method has been attempted. In this study, GC/FID/Olfactometry system was developed. This system can simultaneously sniff and detect GC effluents by traditional GC combined with human olfactory system. The time gap between FID and ODP response was dependent on the kinds and concentrations of chemicals and panels, with more volatile, stronger and shorten breath cycle panel showing narrow time gap. Thus, clear relationship between FID and ODP should be considered to identify the odor-active compounds.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.81-86
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• 2009

Almost all network systems provide an authentication mechanism based on user ID and password. In such system, it is easy to obtain the user password using a sniffer program with illegal eavesdropping. The one-time password and challenge-response method are useful authentication schemes that protect the user passwords against eavesdropping. In client/server environments, the one-time password scheme using time is especially useful because it solves the synchronization problem. In this paper, we propose a new identification scheme One Pass Identification. The security of Password base System is based on the square root problem, and Password base System is secure against the well known attacks including pre-play attack, off-line dictionary attack and server comprise. A number of pass of Password base System is one, and Password base System processes the password and does not need the key. We think that Password base System is excellent for the consuming time to verify the prover.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.627-632
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• 2005

Almost all network systems provide an authentication mechanism based on user ID and password. In such system, it is easy to obtain the user password using a sniffer program with illegal eavesdropping. The one-time password and challenge-response method are useful authentication schemes that protect the user passwords against eavesdropping. In client/ server environments, the one-time password scheme using time is especially useful because it solves the synchronization problem. It is the stability that is based on Square Root problem, and we would like to suggest OPI(One Pass Identification), enhancing the stability for all of the well-known attacks by now including Free-playing attack, off-line Literal attack, Server and so on. OPI does not need to create the special key to read the password. OPI is very excellent in identifying the approved person within a very short time.

• Analytical Science and Technology
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• v.10 no.1
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• pp.1-8
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• 1997

We identified nicotine, cotinine and toluene in high school volunteer's urine by using GC/NPD, GC/FID and GC/MS. To analyze of nicotine and cotinine, urine samples were extracted with diethylether and centrifuged on a benchtop centrifuge for 5 min. The upper organic layer was injected into a GC. The distributions of nicotine and cotinine were $4{\sim}630{\mu}g/L$ and $63{\sim}1,602{\mu}g/L$ in smoking-group, respectively. To analyze of toluene, head space vial was filled with 2mL sodium citrate solution and 1mL of urine. The vial was warmed in a water bath at $55^{\circ}C$ for 20min, and then $250{\mu}L$ of head space air was injected into a GC. The result show that toluene was not detected in all of the volunteers' samples. However, the range of toluene was 0.1~28.0mg/L in glue sniffer's urine samples(NISI data).

• Journal of the Korea Society of Computer and Information
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• v.26 no.6
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• pp.89-96
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• 2021

In this paper, we proposed a sniffer to detect permission smells from developer and third-party libraries' code. Moreover, we conducted an empirical study to investigate unnecessary permissions on large real-world Android apps. Our analysis indicates that permission smell extensively exists in Android apps. According to the results, permission smells exist in most Android apps. In particular, third-party libraries request permission for functionalities that are not used by developers, which cause more smells. Moreover, most developers do not properly disable unnecessary permissions that are declared for third-party libraries. We discussed the impacts of permission smells on user experiences. As a result, the existence of permission smell does not impact the number of downloads. However, apps that have more unnecessary permissions have received lower ratings from users.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.471-480
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• 2006

Recently, multimedia communication services, such as video conferencing and voice over IP, have been rapidly spread. H.323 is an international standard that specifies the components, protocols and procedures that provide multimedia communication services of real-time audio, video, and data communications over packet networks, including IP based networks. H.323 is applied to many commercial services because it supports various network environments and has a good performance. But communication services based on H.323 may have some problem because of current network trouble or mis-implementation of H.323. The understanding of this problem is a critical issue because it improves the quality of service and is easy to service maintenance. In this paper, we implement the analysis system for H.323 protocol wihch includes H.245, H.225.0, RTP, RTCP, and so on. Tills system is able to capture, parse, and present the H.323 protocol in real-time. Through the operation test and performance evaluation, we prove that our system is a useful to analyze and understand the problems for communication services based on H.323.