• East Asian mathematical journal
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• v.30 no.4
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• pp.571-581
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• 2014

Students might find different solutions to the quadratic inequalities according to the range of the number representing the character of the inequalities. They have confusion when the roots of a quadratic inequality are complex numbers since the character of the inequalities generally represents the real number in the mathematics textbooks. Therefore we suggest that we must explain definitely the range of the number representing the character for each inequality question.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.568-573
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• 1998

Volatile compounds in Pinus densiflora were extracted with Likens-Nickerson apparatus for three hours, and were separated and identified by gas chromatography(GC) and mass selective detector(MSD). Twenty six compounds were isolated from Pinus densiflora, identified by GC-MSD and twelve compounds were confirmed by matching retention times of the pure comounds. The main valatile compounds were terpenoids such as limonene(36.2%), $\beta$-pinene(16.9%), $\beta$-myrcene(12.6%) and $\alpha$-pinene(10.9%), and the total amount of these main compounds was 367.9$\mu\textrm{g}$ per 1g of pine twigs.

• The Mathematical Education
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• v.51 no.3
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• pp.211-221
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• 2012

We discovered that definition of a Geometrical Progression(Sequence) have some differences in domestic textbooks & some foreign countries' books. This will be able to cause a chaos when students divide whether a sequence is a Geometrical Progression(Sequence) or not, and a question error when teachers compose questions about convergence conditions of Infinite Geometric progressions & series. We took a question investigation for students about definition of a Geometrical Progression(that is called G. P.), we discovered that high level students have an error about definition of a G. P.. So We modified expressions of terminology in domestic textbooks appropriately through a Geometrical Progression(Sequence), infinite series, & infinite geometrical series in some foreign countries' books.

• The Korean Journal of Physiology
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• v.6 no.1
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• pp.27-31
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• 1972

The activity of Mg and Na-K activated ATPase of homogenate from rat brain cortex was measured in vitro under the variety of conditions. The effects of various hypnotic and tranquilizer such as phenobarbital, amobarbital, diazepam, promazine and chlorpromazine on the activities of both ATPase was investigated and the results was summarized as follows. 1. Na-K ATPase was slightly inhibited by phenobarbital and amobarbital while Mg ATPase was moderately activated by these drugs. 2. Both Mg and Na-K ATPase activities were markedly inhibited by diazepam. 3. Promazine and chlorpromazine markedly inhibited both Mg and Na-K ATPase activities. These findings indicate that remarkable correlation between hypnotic or tranquilizing potency and ATPase inhibition could be observed.

• Journal of Hydrogen and New Energy
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• v.3 no.2
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• pp.1-7
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• 1992

New type of metal hydride heat pump (MHHP) combined with hydrogen compressor was constucted for cooling purpose. A model for calculating the coefficient of performance (COP) is presented for MHHP which consisted of two different stages (enforced and natural stage), and compared with the experimental results. A concept of adiabatic compression work is introduced in the model on the basis of Carnot reversible analysis and the dependence of COP on the various operational parameters is discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.175-176
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• 2014

Identification and authentication of the security requirements of the application area. Individual ID for uniquely be identified. Standard length of the password is limited and should be applied in combination. And must be changed periodically. ID/PW authentication scheme non-reinforced must be provided. The authentication process is defined in the security requirements should be satisfied.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.187-188
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• 2014

Encryption is the process of encoding messages or information in such a way that only authorized parties can read it. Encryption doesn't prevent hacking but it reduces the likelihood that the hacker will be able to read the data that is encrypted. Important information (data) information during transmission or storage of the confidentiality, integrity should be guaranteed. Encryption is one-way and two-way encryption is applied. The encryption key must be guaranteed safety.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.192-193
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• 2014

Attendant services (user) roles (Role) and act on the data used should be based access control and permissions. Large amounts of important information to view and change the pre-approval must be acquired. Non-constant time for the session must control actions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2485-2490
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• 2010

In this paper, gather the sleep environment data of bedroom to sleeping and analyze the relationship between the obtained conditional data and the sleep. Based on this, system provide the optimal sleep environment of individual person by extracting the simulation model. The experiments of system was using H-MOTE2420 sensor composed of temperature/humidity sensor and ambient light sensors. We use difference image method in motion extraction from video for extraction of tossing and turning. In addition, it was entered such as ratio of fatigue, ratio of drinking, ratio of empty stomach as the information of weight can affect to sleep. Resultingly of experience, we can extract the optimal sleep environment. From now on, we will try to enhance to help to lead more pleasant daily life providing proper indoor environment changes depending on the situation even a partial of organic living environments such as eating and work as well as special sleep circumstances.

• Korean Journal of Computational Design and Engineering
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• v.17 no.2
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• pp.97-110
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• 2012

High performance sensors and modern data logging technology with real-time telemetry facilitate system fault diagnosis in a very precise manner. Fault detection, isolation and identification in fault diagnosis systems are typical steps to analyze the root cause of failures. This systematic failure analysis provides not only useful clues to rectify the abnormal behaviors of a system, but also key information to redesign the current system for retrofit. The main barriers to effective failure analysis are: (i) the gathered data (event) logs are too large in general, and further (ii) they usually contain noise and redundant data that make precise analysis difficult. This paper therefore applies suitable pre-processing techniques to data reduction and feature extraction, and then converts the reduced data log into a new format of event sequence information. Finally the event sequence information is decoded to investigate the correlation between specific event patterns and various system faults. The efficiency of the developed pre-filtering procedure is examined with a terminal box data log of a marine diesel engine.