Search

In this paper, we propose a graph-based dependency parsing model using dynamic features. The dynamic features, which are derived from the partial tree during bottom-up chart parsing, play an important role in finding the correct heads. Based on the beneficial aspects of the head-final property of Korean, we suggest a variant of the CYK parsing algorithm with an O(n3) complexity which has the ability to search for the maximum spanning tree (MST) from all projective trees. Compared to Eisner's algorithm, this algorithm is time-efficient in parsing all other head-final languages. We also explain why the graph-based approaches are seldom attempted in parsing morphologically rich languages (MRLs) and suggest a morpheme-level dependency representation as a solution. Finally, we evaluate the proposed method on the KAIST corpus using two discriminative online learning methods (the averaged perceptron algorithm and passive-aggressive algorithm) and show that the trained parser achieves the best reported parsing accuracy. [ABSTRACT FROM AUTHOR]

This paper proposes an efficient masking method for the block cipher SEED that is standardized in Korea. The nonlinear parts of SEED consist of two S-boxes and modular additions. However, the masked version of these nonlinear parts requires excessive RAM usage and a large number of operations. Protecting SEED by the general masking method requires 512 bytes of RAM corresponding to masked S-boxes and a large number of operations corresponding to the masked addition. This paper proposes a new-style masked S-box which can reduce the amount of operations of the masking addition process as well as the RAM usage. The proposed masked SEED, equipped with the new-style masked S-box, reduces the RAM requirements to 288 bytes, and it also reduces the processing time by 38% compared with the masked SEED using the general masked S-box. The proposed method also applies to other block ciphers with the same nonlinear operations. [ABSTRACT FROM AUTHOR]

Current KEPCO's distribution automation system (DAS) provides a very effective restoration solution for the single fault case but cannot handle multiple faults. This paper proposes a two-step restoration scheme—sequential and simultaneous restoration--for multiple fault cases. Efficiency has been achieved by introduction of restoration performance index (RPI) and load-balancing algorithm. Test results to show effectiveness of the proposed scheme are presented, and field experience of DAS in Korea is described as well. [ABSTRACT FROM AUTHOR]

There are several methods available in measuring food taste. The sensory evaluation, for instance, is a typical method for panels to test of taste and recognize smell with their nose by measuring the degree of taste characteristic, intensity, and pleasure. There are many issues entailed in the traditional sensory evaluation method such as forming a panel and evaluation cost; moreover, it is only localized in particular areas. Accordingly, this paper aimed to select food in one particular area, and compare and review the content between sensory evaluations using a taste biological sensor, as well as presenting an analysis of brainwaves using EEG and finally a proposal of a new method for sensory evaluation. In this paper, the researchers have conducted a sensory evaluation whereas a maximum of nine points were accumulated by purchasing eight types of rice wine. These eight types of Makgeolli were generalized by generating multidimensional data with the use of TS-5000z, thus learning mapping points and scaling them. The contribution of this paper, therefore, is to overcome the disadvantages of the sensory evaluation with the usage of the suggested taste biological sensor system. [ABSTRACT FROM AUTHOR]

This paper presents a dynamic programming algorithm to draw optimal intermodal freight routing with regard to international logistics of container cargo for export and import. This study looks into the characteristics of intermodal transport using multi-modes, and presents a Weighted Constrained Shortest Path Problem (WCSPP) model. This study draws Pareto optimal solutions that can simultaneously meet two objective functions by applying the Label Setting algorithm, a type of Dynamic Programming algorithms, after setting the feasible area. To improve the algorithm performance, pruning rules have also been presented. The algorithm is applied to real transport paths from Busan to Rotterdam, as well as to large-scale cases. This study quantitatively measures the savings in both transport cost and time by comparing single transport modes with intermodal transport paths. Last, this study applies a mathematical model and MADM model to the multiple Pareto optimal solutions to estimate the solutions. [ABSTRACT FROM AUTHOR]

Abstract: A large AC generator is an important component of the power system. Researches on the AC generator relaying for the next-generation ECMS and an efficient operation of protection control system are necessary. These require developments on detailed generator modeling and internal fault analysis, and prototyping for multifunctional IED device dedicated to next-generation production. In this paper, over-excitation relaying algorithm is one of the main protection elements which have an important role in DGPS(Digital Generator Protection System), was proposed. This paper first briefly introduces a principles of over-excitation and DFT-based gain compensation algorithm was adopted for the frequency measurement. Subsequently, protection scheme of over-excitation was presented. The 765[kV] modeling data of South Korea using EMTP-RV was used for simulations. The simulation result of over-excitation relaying are also provided. [Copyright &y& Elsevier]

A new algorithm for the determination of adequate generation re-dispatch as a protective measure against voltage instability is presented in this study. The study applies the method to the Jeju island system in Korea with a frequency control by the current sourced converter (CSC) high-voltage direct current (HVDC) system, which regulates the local system frequency by the active power injection from the mainland system. In order to transfer the active power using the CSC HVDC system, reactive power consumption is essential, and the frequency control of the HVDC is very fast. Therefore voltage instability may occur if the dynamic reactive support is not enough in the local power system at severe contingencies such as generator's outages. The authors suggest generation against voltage curves (g–V curves), constructed by generation continuation power flow, and propose the procedure to determine voltage stability limit of active power generation at each generator using g–V curves. An illustrative example of the proposed algorithm is shown as applied to the Jeju island system. [ABSTRACT FROM AUTHOR]

Compound noun segmentation is a key first step in language processing for Korean. Thus far, most approaches require some form of human supervision, such as pre-existing dictionaries, segmented compound nouns, or heuristic rules. As a result, they suffer from the unknown word problem, which can be overcome by unsupervised approaches. However, previous unsupervised methods normally do not consider all possible segmentation candidates, and/or rely on character-based segmentation clues such as bi grams or all-length n-grams. So, they are prone to falling into a local solution. To overcome the problem, this paper proposes an unsupervised segmentation algorithm that searches the most likely segmentation result from all possible segmentation candidates using a word-based segmentation context. As word-based segmentation clues, a dictionary is automatically generated from a corpus. Experiments using three test collections show that our segmentation algorithm is successfully applied to Korean information retrieval, improving a dictionary-based longest-matching algorithm. [ABSTRACT FROM AUTHOR]

River runoff predictions in ungauged basins are one of the major challenges in hydrology. In the past, the approach using a physical-based conceptual model was the main approach, but recently, a solution using a data-driven model has been evaluated as more appropriate through several studies. In this study, a new data-driven approach combining various recurrent neural networks and decision tree-based algorithms is proposed. An advantage of recurrent neural networks is that they can learn long-term dependencies between inputs and outputs provided to the network. Decision tree-based algorithms, combined with recurrent neural networks, serve to reflect topographical information treated as constants and can identify the importance of input features. We tested the proposed approach using data from 25 watersheds publicly available on the Korean government's website. The potential of the proposed approach as a regional hydrologic model is evaluated in the view that one regional model predicts river runoff in various watersheds using the leave-one-out cross-validation regionalization setup. [ABSTRACT FROM AUTHOR]

In general, SFCLs can have a negative impact on the protective coordination in power transmission system because of the variable impedance of SFCLs. It is very important to solve the protection problems of the power system for the successful application of SFCLs to real power transmission system. This paper reviews some protection problems which can be caused by the application of 154 kV SFCLs to power transmission systems in South Korea. And then we propose an adaptive protection algorithm to solve the problems. The adaptive protection algorithm uses the real time information of the SFCL system operation. [ABSTRACT FROM AUTHOR]

Abstract: The method of extracting offshore wind field from SAR satellite images for offshore wind resource assessment shows some discrepancies in the calculated wind speed depending on which of the CMOD algorithms is used. This paper compared different algorithms, such as CMOD_IFR2, CMOD4, CMOD5, in order to find the suitable CMOD algorithm for the southern offshore area of the Korean Peninsula, which belongs to the zone influenced by the archipelago, by calculating the relative errors with reference to the Korea wind map of representative weather days by season. The result is that CMOD-IFR2 shows a tendency towards excessive estimation of wind speed, while CMOD4 shows the lowest RMSE values of wind speed differences with respect to the Korea wind map. Based on this result, we have concluded that, for the southern offshore area of the Korean Peninsula which belongs to the medium-range wind speed zone, CMOD4 is the suitable algorithm. [Copyright &y& Elsevier]

By 2026, Korea is expected to surpass the UN's definition of an aged society and reach the level of a superaged society. With an aging population come increased disorders involving the spine. To prevent unnecessary spinal surgery and support scientific diagnosis of spinal disease and systematic prediction of treatment outcomes, we have been developing e-Spine, which is a computer simulation model of the human spine. In this paper, we present the Korean spine database and automatic surface mesh intersection algorithm to construct e-Spine. To date, the Korean spine database has collected spine data from 77 cadavers and 298 patients. The spine data consists of 2D images from CT, MRI, or X-ray, 3D shapes, geometry data, and property data. The volume and quality of the Korean spine database are now the world's highest ones. In addition, our triangular surface mesh intersection algorithm automatically remeshes the spine-implant intersection model to make it valid for finite element analysis (FEA).This makes it possible to run the FEA using the spine-implant mesh model without any manual effort. Our database and surface mesh intersection algorithm will offer great value and utility in the diagnosis, treatment, and rehabilitation of patients suffering from spinal diseases. [ABSTRACT FROM AUTHOR]

Abstract: In practice, a train-conflict resolution is decentralized around dispatchers each of whom controls a few segments in a global railway network with her rule-of-thumb to operational data. Conceptually, the global sub-optimality or infeasibility of the decentralized system is resolved by a network controller who coordinates the dispatchers and train operators at the lower layers on a real-time basis. However, such notion of a multi-layer system cannot be effectual unless the top layer is able to provide a global solution soon enough for the dynamic lower layers to adapt in a seamless manner. Unfortunately, a train-conflict resolution problem is NP-hard as formally established in this paper and an effective solution method traded off between computation time and solution quality has been lacking in literature. Thus, we propose a column-generation-based algorithm that exploits the separability of the problem. A key ingredient of the algorithm is an efficient heuristic for the pricing subproblem for column generation. Tested on the real data from the Seoul metropolitan railway network, the algorithm provides near-optimal conflict-free timetables in a few seconds for most cases. The performance of the proposed algorithm is compared to the ones of the previous MIP-based heuristic by and the priority-based heuristic by . [ABSTRACT FROM AUTHOR]

Abstract: This paper proposes a gait planning and control algorithm for the quadruped robot pet commercialized by Dasarobot, Korea. Reliable motion and online characteristics are the key requisites for the motion planning algorithm of a commercialized robot. At joint control level of the proposed gait control, sample-based interpolation makes joint trajectory tractable for small motor and controller of the miniaturized robot. Centroid body sway ensures walking stability to achieve reliability of the proposed gaits at the motion planning level. By using ground coordinates representation, it is possible to integrate several online gaits and realize a compact and efficient gait planning algorithm. Experimental results are presented to verify the proposed gait planning and control algorithm. [Copyright &y& Elsevier]

Global warming, one of the most serious aspects of climate change, can be expected to cause rising sea levels. These have in turn been linked to unprecedentedly large typhoons that can cause flooding of low-lying land, coastal invasion, seawater flows into rivers and groundwater, rising river levels, and aberrant tides. To prevent typhoon-related loss of life and property damage, it is crucial to accurately estimate storm-surge risk. This study therefore develops a statistical model for estimating such surges' probability based on surge data pertaining to Typhoon Maemi, which struck South Korea in 2003. Specifically, estimation of non-exceedance probability models of the typhoon-related storm surge was achieved via clustered separated peaks-over-threshold simulation, while various distribution models were fitted to the empirical data for investigating the risk of storm surges reaching particular heights. To explore the non-exceedance probability of extreme storm surges caused by typhoons, a threshold algorithm with clustering methodology was applied. To enhance the accuracy of such non-exceedance probability, the surge data were separated into three different components: predicted water level, observed water level, and surge. Sea-level data from when Typhoon Maemi struck were collected from a tidal-gauge station in the city of Busan, which is vulnerable to typhoon-related disasters due to its geographical characteristics. Fréchet, gamma, log-normal, generalized Pareto, and Weibull distributions were fitted to the empirical surge data, and the researchers compared each one's performance at explaining the non-exceedance probability. This established that Weibull distribution was better than any of the other distributions for modelling Typhoon Maemi's peak total water level. Although this research was limited to one city on the Korean Peninsula and one extreme weather event, its approach could be used to reliably estimate non-exceedance probabilities in other regions where tidal-gauge data are available. In practical terms, the findings of this study and future ones adopting its methodology will provide a useful reference for designers of coastal infrastructure. [ABSTRACT FROM AUTHOR]

Since every single test has some limitations for detecting toxigenic Clostridium difficile, multistep algorithms are recommended. This study aimed to compare the current, representative diagnostic algorithms for detecting toxigenic C. difficile, using VIDAS C. difficile toxin A&B (toxin ELFA), VIDAS C. difficile GDH (GDH ELFA, bioMérieux, Marcy-l’Etoile, France), and Xpert C. difficile (Cepheid, Sunnyvale, California, USA). In 271 consecutive stool samples, toxigenic culture, toxin ELFA, GDH ELFA, and Xpert C. difficile were performed. We simulated two algorithms: screening by GDH ELFA and confirmation by Xpert C. difficile (GDH + Xpert) and combined algorithm of GDH ELFA, toxin ELFA, and Xpert C. difficile (GDH + Toxin + Xpert). The performance of each assay and algorithm was assessed. The agreement of Xpert C. difficile and two algorithms (GDH + Xpert and GDH+ Toxin + Xpert) with toxigenic culture were strong (Kappa, 0.848, 0.857, and 0.868, respectively). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of algorithms (GDH + Xpert and GDH + Toxin + Xpert) were 96.7%, 95.8%, 85.0%, 98.1%, and 94.5%, 95.8%, 82.3%, 98.5%, respectively. There were no significant differences between Xpert C. difficile and two algorithms in sensitivity, specificity, PPV and NPV. The performances of both algorithms for detecting toxigenic C. difficile were comparable to that of Xpert C. difficile. Either algorithm would be useful in clinical laboratories and can be optimized in the diagnostic workflow of C. difficile depending on costs, test volume, and clinical needs. [ABSTRACT FROM AUTHOR]

Polarimetric measurements are sensitive to the sizes, concentrations, orientations, and shapes of raindrops. Thus, rainfall rates calculated from polarimetric radar are influenced by the raindrop shapes and canting. The mean raindrop shape can be obtained from long-term raindrop size distribution (DSD) observations, and the shapes of raindrops can play an important role in polarimetric rainfall algorithms based on differential reflectivity (ZDR) and specific differential phase (KDP). However, the mean raindrop shape is associated with the variation of the DSD, which can change depending on precipitation types and climatic regimes. Furthermore, these relationships have not been studied extensively on the Korean Peninsula. In this study, we present a method to find optimal polarimetric rainfall algorithms for the Korean Peninsula by using data provided by both a twodimensional video disdrometer (2DVD) and the Bislsan Sband dual-polarization radar. First, a new axis-ratio relation was developed to improve radar rainfall estimations. Second, polarimetric rainfall algorithms were derived by using different axis-ratio relations. The rain gauge data were used to represent the ground truth situation, and the estimated radar-point hourly mean rain rates obtained from the different polarimetric rainfall algorithms were compared with the hourly rain rates measured by a rain gauge. The daily calibration biases of horizontal reflectivity (ZH) and differential reflectivity (ZDR) were calculated by comparing ZH and ZDR radar measurements with the same parameters simulated by the 2DVD. Overall, the derived new axis ratio was similar to the existing axis ratio except for both small particles (≼2 mm) and large particles (≽5.5 mm). The shapes of raindrops obtained by the new axis-ratio relation carried out with the 2DVD were more oblate than the shapes obtained by the existing relations. The combined polarimetric rainfall relations using ZDR and KDP were more efficient than the single-parameter rainfall relation for estimated 2DVD rainfall; however, the R(ZH, ZDR) algorithm showed the best performance for radar rainfall estimations, because the rainfall events used in the analysis consisted mainly of weak precipitation and KDP is relatively noisy at lower rain rates (≼10mmh-1). Some of the polarimetric rainfall algorithms can be further improved by new axis-ratio relations. [ABSTRACT FROM AUTHOR]

Backgroud Procurement of tumor tissue is mandatory for a mutation analysis in patients with non-small cell lung cancer. The purpose of this study was to evaluate the usefulness of bronchoscopic biopsy and endobronchial ultrasound-guided transbronchial needle aspiration ( EBUS-TBNA) biopsy for detecting epidermal growth factor receptor ( EGFR) and KRAS mutations in routine practice. Methods Tumor DNA was extracted from formalin-fixed paraffin-embedded tissues, and amplifications of exons 18-21 of EGFR and codons 12, 13 and 61 of KRAS were performed using polymerase chain reaction ( PCR). PCR products were subjected to direct sequencing in both directions. Results Of 211 consecutive specimens, 201 (95.3%) were available for EGFR mutation analysis, and 196 (92.9%) were adequate for KRAS mutation analysis. EGFR and KRAS mutations were detected in 14.9% and 5.4%, respectively. A median of 16 days was spent from biopsy to the final report for either EGFR or KRAS mutation status. The detection rates for both mutations were similar between bronchoscopic biopsy and EBUS-TBNA (P > 0.05). Female gender (53.3%), never smoker (63.3%), and adenocarcinoma (96.7%) were predominant in patients with EGFR mutations. Among patients with adenocarcinoma (n = 104), the frequencies of EGFR and KRAS mutations were 27.9% and 10.6%, respectively. Conclusions Small tissue samples obtained by bronchoscopic biopsy and EBUS-TBNA are sufficient for detecting EGFR and KRAS mutations in routine practice. Therefore, concurrent mutational analyses of small tissue samples should be considered at the time of initial diagnosis. [ABSTRACT FROM AUTHOR]

We evaluated the precision of land surface temperature (LST) operationally retrieved from the Korean multipurpose geostationary satellite, Communication, Ocean and Meteorological Satellite (COMS). The split-window (SW)-type retrieval algorithm was developed through radiative transfer model simulations under various atmospheric profiles, satellite zenith angles, surface emissivity values and surface lapse rate conditions using Moderate Resolution Atmospheric Transmission version 4 (MODTRAN4). The estimation capabilities of the COMS SW (CSW) LST algorithm were evaluated for various impacting factors, and the retrieval accuracy of COMS LST data was evaluated with collocated Moderate Resolution Imaging Spectroradiometer (MODIS) LST data. The surface emissivity values for two SW channels were generated using a vegetation cover method. The CSW algorithm estimated the LST distribution reasonably well (averaged bias = 0.00 K, Root Mean Square Error (RMSE) = 1.41 K, correlation coefficient = 0.99); however, the estimation capabilities of the CSW algorithm were significantly impacted by large brightness temperature differences and surface lapse rates. The CSW algorithm reproduced spatiotemporal variations of LST comparing well to MODIS LST data, irrespective of what month or time of day the data were collected from. The one-year evaluation results with MODIS LST data showed that the annual mean bias, RMSE and correlation coefficient for the CSW algorithm were -1.009 K, 2.613 K and 0.988, respectively. [ABSTRACT FROM AUTHOR]

Conclusion: Establishing a straight and firm septum supporting the overlying nasal structures is the most important step in correcting the post-traumatic combined deviated and saddle nose. Objectives: To present a surgical algorithm and key maneuvers that were successfully applied in the correction of post-traumatic combined deviated and saddle nose deformity. Methods: Twenty-five patients who had undergone primary rhinoplasty for a post-traumatic combined deviated and saddle nose were included. The patterns of deformity, surgical maneuvers, surgical results, and complications were analyzed using retrospective chart review, telephone interview, and preoperative and postoperative photographs. Results: Three distinct groups undergoing different techniques to correct the deformity were noted. Eighteen patients (72%) with intact septal support were treated by straightening the nose and septum followed by simple onlay grafts. Five patients (20%) with loss of septal support needed septal reconstruction. In two patients (8%) showing deviation, generalized saddling, and loss of septal support, a dorsal graft integrated to an extended columellar strut was performed, bypassing the major septal reconstruction. The key maneuvers for correction were dorsal onlay graft (100%), septoplasty (92%), and bilateral osteotomies (84%). No major complications were found. Objective evaluation showed complete correction of the deviation and saddling in 76%. [ABSTRACT FROM AUTHOR]

The application of a two-dosemeter system with its algorithm, as well as a test of its use in an inhomogeneous high-radiation field, is described in this study. The goal was to improve the method for estimating the effective dose equivalent during maintenance periods at Korean Nuclear Power Plants (NPPs). The use of this method in Korean and international NPPs, including those NPPs in the USA and Canada, was also investigated. The algorithms used by the the American National Standards Institute, Lakshmanan, the National Council on Radiation Protection and Measurements (NCRP), the Electric Power Research Institute and Kim were extensively analysed as two-dosemeter algorithms. Their possible application to NPPs was evaluated using data for each algorithm from two-dosemeter results that were obtained from an inhomogeneous high-radiation field during maintenance periods at Korean NPPs. The NCRP algorithm (55:50) was selected as an optimal two-dosemeter algorithm for Korean NPPs by taking into account the field test results and the convenience of wearing two dosemeters. [ABSTRACT FROM PUBLISHER]

Objective. The Korean Medication Algorithm Project for Bipolar Disorder (KMAP-BP 2002) was developed in 2002. The aim of this study was to evaluate the clinical feasibility, efficacy, and safety of implementation of the KMAP-BP 2002 algorithm in clinical situations. Methods. Participating investigators were asked to follow the KMAP-BP 2002 algorithm as much as possible, but they were allowed to change their treatment strategies as they considered necessary. The enrolled patients were followed for 4 months. Results. A total of 126 bipolar patients were consecutively enrolled and 73% were treated according to the KAMP-BP 2002 algorithm. The majority (79%) of manic patients demonstrated a treatment response at the starting step and were thus treated with only one step of the algorithm. An atypical antipsychotic drug was coadministered with a mood stabilizer from the beginning of treatment in almost all manic patients. There was a significant improvement in manic symptoms (F=187.32, P<0.001) over the 4-month testing period. There was no significant increase in side effects at the endpoint. Overall, the investigators were satisfied with implementing the algorithm. Conclusion. These results suggest that the KMAP-BP 2002 algorithm could be implemented effectively and safely in clinical practice. [ABSTRACT FROM AUTHOR]

The portfolio management for trading in the stock market poses a challenging stochastic control problem of significant commercial interests to finance industry. To date, many researchers have proposed various methods to build an intelligent portfolio management system that can recommend financial decisions for daily stock trading. Many promising results have been reported from the supervised learning community on the possibility of building a profitable trading system. More recently, several studies have shown that even the problem of integrating stock price prediction results with trading strategies can be successfully addressed by applying reinforcement learning algorithms. Motivated by this, we present a new stock trading framework that attempts to further enhance the performance of reinforcement learning-based systems. The proposed approach incorporates multiple Q-learning agents, allowing them to effectively divide and conquer the stock trading problem by defining necessary roles for cooperatively carrying out stock pricing and selection decisions. Furthermore, in an attempt to address the complexity issue when considering a large amount of data to obtain long-term dependence among the stock prices, we present a representation scheme that can succinctly summarize the history of price changes. Experimental results on a Korean stock market show that the proposed trading framework outperforms those trained by other alternative approaches both in terms of profit and risk management. [ABSTRACT FROM AUTHOR]