• Journal of the Korean Society of Radiology
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• v.5 no.5
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• pp.295-302
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• 2011

To n the field of nuclear medicine, with regard to checking regular patients, from the moment they register up to the doctor's diagnosis, the person in charge of the checks can find errors in the diagnosis, reexamine, reanalyze the results or save images to PACS. Through this process, the results obtained from the readings are delayed due to checks and additional tests which occur in hospitals, causing patient satisfaction and affected reliability. Accordingly, the purpose is to include visual inspection of the results to minimize error, improve efficiency and increase patient satisfaction. Nuclear medicine and imaging tests from examines at Asan Medical Center, Seoul, from March 2008 to December 2008, were analyzed for errors. The first stage, from January 2009 to December 2009, established procedures and know-how. The second stage from January 2010 until June 2010 conducted Pre-and Post-filtering assessment, and the third stage from July 2010 until October 2010 consisted of cross-checks and attaching stickers and comparing error cases. Of 92 errors, the 1st, 2nd and 3rd stage had 32 cases, and there were 46 cases after the 4th stage, with the overall errors reduced by 74.3% from 94.6%. In the field of general nuclear medicine, where various kinds of checks are performed according to the patient's needs, analysis, image composition, differing images in PACS, etc, all have the potential for mistakes to be made. In order to decrease error rates, the image can continuously Cross-Check and Confirm diagnosis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.617-626
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• 2008

Opportunistic Beamforming (OBF) offers a way to provide the multiuser diversity even in slow fading channel by using randomly generated beam weights, leading to the substantially reduced feedback in the form of the instantaneous SNR from users. In spite of the advantage of the reduced feedback, the imperfect channel estimation might influence the quality of the estimated SNR and channel scheduler so bad that the selected AMC level would be higher than the achievable rate of the actual channel, resulting the corruption of transmitted packet. In this paper, we propose a conservative link adaptation, where the estimated SNR is scaled down by a conservative factor which minimizes the variance of the maximum difference between the actual channel SNR and the resultant SNR. To support the proposed scheme, we analyze the statistics of the difference of the channel SNR and the estimated SNR. Simulation results show that the introduction of conservative factor achieves more than two-fold performance improvement in the presence of channel estimation error and the fairness of PF scheduler is maintained when the least squared channel estimator is applied.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.237-250
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• 2017

This study focuses on the maintenance of the registration details of the cadastral study (drawings, chiefs) in relation to Uiwang city real estate administration information unification project by the data maintenance business. The purpose of this study is to provide high quality data and improve the efficiency of data maintenance business in the unification of real estate administration information together with the intellectual study diffusion maintenance model in the future. In this study, based on the results of the intellectual study data maintenance project and the effectiveness of institutional, temporal and cost aspects, it was able to show the effect of the data maintenance project. And analyzed the current situation, typed the error shown here, and developed the maintenance plan and maintenance result.

• Journal of Navigation and Port Research
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• v.41 no.4
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• pp.173-180
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• 2017

Underwater communications are degraded as a result of inter symbol interference in multipath channels. Therefore, a channel coding scheme is essential for underwater communications. Packets consist of a PN sequence and a data field, and the uncoded PN sequence is used to estimate the frequency and phase offset using a Doppler and phase estimation algorithm. The estimated frequency and phase offset are fed to a coded data field to compensate for the Doppler and phase offset. The PN sequence is generally utilized to acquire the synchronization information, and the bit error rate of an uncoded PN sequence predicts the performance of the coded data field. To ensure few errors, we resort to powerful BCJR decoding algorithms of convolutional codes with rates of 1/2, 2/3, and 3/4. We use this powerful channel coding algorithm to present an efficient receiver structure based on the relation between the bit error of the uncoded PN sequence and coded data field in computer simulations and lake experiments.

• Korean Journal of Cognitive Science
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• v.14 no.4
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• pp.1-7
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• 2003

The common features of the behavioral inhibition and the action monitoring that are considered as one of the executive functions were investigated using event-related brain potentials (ERPs) and source localization analysis. The electrophysiological correlates of behavioral inhibition and action monitoring ate analyzed when the subjects performed the Go/NoGo task. Two ERP components of behavioral inhibition termed as N200 and P300 in NoGo condition were differ from those of Go condition, that is the amplitudes of NoGo N200 and P300 are largest on the fronto-central region, which may reflect the inhibitory control of frontal lobe required in NoGo condition. The error-related negativity (ERN) observed on the fronto-central region when the subjects committed error was much larger in amplitude and faster in latency than those of the correct-related negativity (CRN), which may indicate that the signal of action monitoring is much more required for the error response. The correlation analysis for the ERP components of behavioral inhibition and action monitoring revealed the significant negative correlation among the latencies of NoGo N200 and P300 and the amplitude of ERN, which may reflects that the faster subjects inhibit response, the more monitor their own action. The close relationship between behavioral inhibition and action monitoring was also supported by the results of source localization analysis, which showed the common neural sources of NoGo N200 and ERN was anterior cingulate cortex.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.25-31
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• 2011

Principal component analysis (PCA) is a well-known method for dimensionality reduction and feature extraction. Although PCA has been applied in many areas successfully, it is sensitive to outliers due to the use of sum-square-error. Several variants of PCA have been proposed to resolve the noise sensitivity and, among the variants, improved robust fuzzy PCA (RF-PCA2) demonstrated promising results. RF-PCA2, however, still can fall into a local optimum due to equal initial membership values for all data points. Another reason comes from the fact that RF-PCA2 is based on sum-square-error although fuzzy memberships are incorporated. In this paper, a variant of RF-PCA2 called RF-PCA3 is proposed. The proposed algorithm is based on the objective function of RF-PCA2. RF-PCA3 augments RF-PCA2 with the objective function of PCA and initial membership calculation using data distribution, which make RF-PCA3 to have more chance to converge on a better solution than that of RF-PCA2. RF-PCA3 outperforms RF-PCA2, which is demonstrated by experimental results.

• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.55-67
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• 2009

In Korea, previously implemented road construction project caused a big budget waste due to overestimation of transport demand. There could be reasons for such inaccuracy of transport demand estimation, but the main reasons are: (1) low reliability of used basic road transport data and (2) inadequate sharing of data among agencies/departments. The National Transport Database and the Household Travel Database in Seoul Metropolitan Area, two representing basic road transport database, will be used to the establishment of a road construction plan that will be promoted afterwards. However, these materials have problems such as low reliability and inadequateness, too. Hence, focusing on transport demand estimation related databases, this paper will make proposals for enhancing their reliability and data sharing.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.292-300
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• 1995

This paper present a new dynamic HRA (Human Reliability Analysis) method and its application for Quantifying the human error probabilities in implementing an accident management action. For comparisons of current HRA methods with the new method, the characteristics of THERP, HCR, and SLIM-MAUD, which are most frequently used methods in PSAs, are discussed. The action associated with the implementation of the cavity flooding during a station blackout sequence is considered for its application. This method is based on the concepts of the quantified correlation between the performance requirement and performance achievement. The MAAP 3.0B code and Latin Hypercube sampling technique are used to determine the uncertainty of the performance achievement parameter. Meanwhile, the value of the performance requirement parameter is obtained from interviews. Based on these stochastic distributions obtained, human error probabilities are calculated with respect to the various means and variances of the timings. It is shown that this method is very flexible in that it can be applied to any kind of the operator actions, including the actions associated with the implementation of accident management strategies.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.234-239
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• 2021

The purpose of this paper is to find out the nature of language variation by exploring the ways of the progress of the language variation that produces all English-lects, i.e., the World Englishes. The study of language variation in linguistics is a hybrid enterprise, so the study of World Englishes has led to the recognition of a highly diverse set of all English-lects, encompassing regional dialects, sociolects, ethnolects and (post-)colonial dialects of World Englishes. In this paper, we propose a hybrid language variation model with three interacting factors of social distancing, on/off-contact, and linguistic diversity to examine the characteristics of language variation. In the context of World Englishes, the social distance is typically low in terms of their local location (country/speech) for local purposes. The social distance also varies based on online/offline communication modes and other social factors like gender, age and ethnic groups, resulting in all English-lects. To clarify the nature of World Englishes, the core Englishes, BrE, AmE and CanE are discussed here.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.73-80
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• 2013

Because the damages of corrosion resulting from the chloride ion are very serious, many research studies have been performed to measure the penetration depth of the chloride ion. However, there is a problem with data selection obtained from collection during experiments. In this study, it appears that the collected data are not conformed to a normal distribution. The result of this study will play a very important role, as a first step for the development and construction of a forecasting system to help determine a reliable service lifetime of marine structures.