• Journal of Sensor Science and Technology
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• v.15 no.6
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• pp.433-441
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• 2006

Because of the low power and low rate of a sensor network, outlier is frequently occurred in the time series data of sensor network. In this paper, we suggest periodic pattern analysis that is applied to the time series data of sensor network and predict outlier that exist in the time series data of sensor network. A periodic pattern is minimum period of time in which trend of values in data is appeared continuous and repeated. In this paper, a quantization and smoothing is applied to the time series data in order to analyze the periodic pattern and the fluctuation of each adjacent value in the smoothed data is measured to be modified to a simple data. Then, the periodic pattern is abstracted from the modified simple data, and the time series data is restructured according to the periods to produce periodic pattern data. In the experiment, the machine learning is applied to the periodic pattern data to predict outlier to see the results. The characteristics of analysis of the periodic pattern in this paper is not analyzing the periods according to the size of value of data but to analyze time periods according to the fluctuation of the value of data. Therefore analysis of periodic pattern is robust to outlier. Also it is possible to express values of time attribute as values in time period by restructuring the time series data into periodic pattern. Thus, it is possible to use time attribute even in the general machine learning algorithm in which the time series data is not possible to be learned.

• Applied Biological Chemistry
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• v.48 no.2
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• pp.140-149
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• 2005

In order to examine the changes of commercial value during storage conditions and shelf-life of Chungkookjang, response surface methodology of SAS program was applied to monitor orgenoleptic properties and color changes to determine optimum storage conditions. Lightness (L) value of vacuum-packed Chungkookjang showed under the 1% significance probability with high influence in all conditions such as sterilized temperature, storage time and storage temperature. Redness (a) value of vacuum-packed Chungkookjang was increased during highly sterilized and storage temperatures, and was individually influenced. One of the generally packed sample also showed that significance value was influenced under 10%, during high storage temperature. Yellowness (b) value of vacuum-packed Chungkookjang showed the significance probability under 1% during storage time and temperature, and under 5% during sterilized temperature. Also, stational point showed saddle type in both packaging samples. In case of vacuum-packed Chungkookjang, compatibility of odor was influenced by sterilized temperature under 10% significance probability. But generally packed samples have an effect on storage time under 1% significance probability effect on storage time, and sterilized temperature under 5%. In case of vacuum-packed Chungkookjang, compatibility of taste was highly concerned with storage time under 1% significance probability, whereas generally packed samples were concerned with storage temperature under 5% significance probability. Overall palatability of vacuum-packed samples showed maximum value of 5.15 on sterilized temperature ($61.92^{\circ}C$), storage temperature ($6.79^{\circ}C$) and storage time (56.48 days) during storage.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.395-400
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• 2004

In most physical processes, the transfer function includes time-delay, and in the general distributed control system using computer network, there exists inherent time-delay caused by the spatial separation between controllers and actuators. This work deals with the synthesis of a discrete-time controller for a nonlinear system and proposes a new effective method to compensate the influence of input time-delay. The controller is synthesized by using input/output linearization. Under the circumstance that input time-delay exists, the system response has more overshoot and tends to diverge. For these reasons, the controller has to produce future input value that will be needed for the system. In order to calculate the future input value, some predictors are adopted. Using the discretization via Euler's method, numerical simulations about the Van der Pol system are performed to evaluate the performance of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.9
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• pp.953-959
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• 1992

As the TC(time-current) curve corresponding to symmetrical time invariant RMS value has been traditionally chosen and used for setting the relay, it has caused the misoperation errors on relay coordination because of CT secondary current being actually an asymmetrical time varying RMS value. In this paper, an algorithm for calculating the relay operating time is developed to study the asymmetrical effect using the step-by-step method. We represent the relay operating time errors between with and without DC offset versus PSM(plug setting multiplier), TMS(time multiplier setting) and X/R ratio. And also we present the correction factor. Finally we confirm the validity of this technique through the case study.

• Journal of Korea Multimedia Society
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• v.14 no.6
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• pp.785-793
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• 2011

Since then, with the advance of computing environment, various Internet services are emerging and the importance of user authentication technology is increasing for verifying users authorized to use such services. Along with the advance of authentication technology, research is being made actively on one time password, which is used once in a session and then discarded. In existing one time passwords, however, the values of one time passwords in a created table are stored in serial order, and therefore, if the seed value and the number of one time passwords used are disclosed, one may infer the value of the one time password to be used next. What is more, one time passwords of the S/Key type have the problem that the number of uses is fixed. In this paper, We analysis the existing one time password. Also, We propose one time password methods using elliptic curve cryptography scheme and using enhanced randomness with time value.

• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.41-52
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• 1999

Recently, much literature has surveyed the economic effects of transportation investment, focusing on the relationship between transportation infrastructure investment and economic development. Although the conventional views assume that transportation investment stimulates economic growth, the results of recent studies are not conclusive and in some cases reject the conventional views. The contradictory results are linked with double counting Problem and Keynesian/Neo-classical economics theory. This article investigates the economic effects of road transportation with regard to freight transport using Stated Preference technique. This study examines, in particular, the value of time saving for freight which has been rarely studied in this area. In the first part, the value of time saving, excluding the value for driver and operating cost, is theoretically investigated through the model of continuous review system and periodic review system. At last, the empirical study using the Seated Preference technique shows the value of time saving for freight and the value of reliability, compared with other studies and the value of those in COBA. The result makes us conclude that road investment produces the secondary effects as well as the direct benefit such as time saving for passengers, operating cost saving. and accident cost reduction. The secondary effect includes the contribution to economic development.

• Fashion & Textile Research Journal
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• v.7 no.5
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• pp.542-546
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• 2005

This study was investigated to establish the optimum conditions of dyeing silk fabric with Brassica campestris. This experiment was done under different dyeing conditions of dye concentration, dyeing temperature, dyeing time, dyeing repeating times, and mordants which were treated pre, syn, and post methods. The effects of dyeing conditions and mordanting were evaluated in terms of dyeaffinity(K/S value) and CIE-Lab color factors. Also, the effect of mordanting on color fastnesses was assessed. The dyeaffinity increased remarkably as dye concentration increased up to 200% owf. The dyeaffinity increased continuously with dyed temperature and reached dyeing equilibrium at $80^{\circ}C$. The maximum dyeaffinity was observed at 30minutes of dyeing time. In the relationship between the K/S value and dyeing repeating times, the K/S value became higher as repeating time was increased. The changes of surface color and colorfatness of dyes were not increased greatly on all mordanting states. The extracts of Brassica campestris produced mainly yellow color in silk fabric. The antimicrobial activity existed slightly as the ratio of 22.7%.

• Journal of Chest Surgery
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• v.16 no.1
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• pp.83-90
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• 1983

During the period of March 1981 to September 1982 a series of survey has been done on the value of amylase in blood and urine of 24 patients who went through the operation of heart surgery, for congenital and acquired heart diseases, with extracorporeal circulation at the Department of Thoracic _ Cardiovascular Surgery, School of Medicine, Hanyang University. In order to analyze the iteration and inter-relation of the value of amylase in blood and urine and the extra corporeal circulation time. The duration of extra-corporeal circulation time up to 60 minutes was classified as Group A while above 60 minutes was classified as Group B. The results are as follow; 1. 3 patients [23.07%] among 13 patients of Group A and 3 patients [27.27%] among 11 patients, showed increased amylase value after the surgery. 2. The average value in blood after operation was 120.3190.71 unit in Group A and 130.90113.15 unit in Group B. It was 11.59 units [9.63%] higher in Group A than in Group B. 3. 1 patient [7.7%] among 13 patients of Group A and 2 patients[18.18%] among 11 patients of Group B, the frequency of Group B was 10.48% higher. 4. The average Value of amylase in urine after the surgery was 111.9254.87 unit in Group A and 151.54111.17 unit in Group B. It was 39.62 unit [32.72%] higher in Group A than in Group B. 5. The longer the duration of extra corporeal circulation time showed the higher the amylase value in blood and urine after the operation. 6. Although the value of amylase in blood and urine was increased after operation, no patients Were found to have developed clinical pancreatitis.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.3
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• pp.35-46
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• 1992

Recently, the fuzzy theory has been adopted broadly to the applications of image processing. Especially the fuzzy clustering algorithm is adopted to image segmentation to reduce the ambiguity and the influence of noise in an image.But this needs lots of memory and execution time because of the great deal of image data. Therefore a new image segmentation algorithm is needed which reduces the memory and execution time, doesn't change the characteristices of the image, and simultaneously has the same result of image segmentation as the conventional fuzzy clustering algorithm. In this paper, for image segmentation, an extended fuzzy clustering algorithm is proposed which uses the occurence of data of the same characteristic value as the weight of the characteristic value instead of using the characteristic value directly in an image and it is proved the memory reduction and execution time reducted in comparision with the conventional fuzzy clustering algorithm in image segmentation.

• Journal of Korea Foundry Society
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• v.8 no.4
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• pp.459-466
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• 1988

This study was carried out in the austempering temperature and time after Ni, Mo addition in purpose of modification of impact toughness of austempered ductile irons. Addition of alloy element and austempering treatment of $900^{\circ}C$ 60 minutes followed by $300^{\circ}C$, $350^{\circ}C$ and $400^{\circ}C$ for 60 minutes, in this case impact value was increased by ideal mixed structure. But impact value was decreased when holing time is 120minutes, this is attributed to segregation and carbide precipitation from high carbon austenite. Highest impact value was obtained by $350^{\circ}C$ (Mo-addition) and $400^{\circ}C$ (Ni-addition). This phenomena was caused by presence of remained austenite. At all austempering temperature,, Ni-added specimen showed higher impact values than that of Mo-added specimen. And hardness property was affected by austempering temperature and holding time rather than amounts of alloying element.