• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.164-167
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• 2022

In table Machine comprehension, the knowledge required for language models or the structural form of tables changes depending on the domain, showing a greater performance degradation compared to text data. In this paper, we propose a pre-learning data construction method and an adversarial learning method through meaningful tabular data selection for constructing a pre-learning table language model robust to these domain changes in table machine reading. In order to detect tabular data sed for decoration of web documents without structural information from the extracted table data, a rule through heuristic was defined to identify head data and select table data was applied. An adversarial learning method between tabular data and infobax data with knowledge information about entities was applied. When the data was refined compared to when it was trained with the existing unrefined data, F1 3.45 and EM 4.14 increased in the KorQuAD table data, and F1 19.38, EM 4.22 compared to when the data was not refined in the Spec table QA data showed increased performance.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.281-290
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• 2017

As various stakeholders are involved in construction projects, disputes between the parties are more likely to occur, which is a very important issue for the participants in the projects. Claims in construction projects, however, are very complex and thus difficult to manage. In particular, as the cause of a claim in the preceding stage that has not been resolved in a timely manner has an effect on the cause of a claim in the following stage, it is difficult to find a point of compromise regarding a claim caused by the relationship between the causes that occur in the preceding and following stages. In this regard, this study sought to examine the rules for the generation of change order claims, which occur most frequently among the construction claims, and thus to select the key management targets through the analysis of the relationship between the causes of claims arising in the preceding and following stages for the efficient management of claims. It is expected that the use of rules for the generation of change order claims as well as of representative and similar cases will help the construction practitioners in judging claims, considering the relationships among the causes of the claims. Meanwhile, in this study, association analysis was conducted regarding the causes of the occurrence of change order claims in a design-build delivery method, and therefore, it is necessary to verify the effectiveness of the method when applied to other delivery methods.

• Geomechanics and Engineering
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• v.36 no.4
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• pp.355-366
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• 2024

The original elastoplastic Hardening Soil model is formulated actually partly under hexagonal pyramidal Mohr-Coulomb failure criterion, and can be only used in specific stress paths. It must be completely generalized under Mohr-Coulomb criterion before its usage in engineering practice. A set of generalized constitutive equations under this criterion, including shear and volumetric yield surfaces and hardening laws, is proposed for Hardening Soil model in principal stress space. On the other hand, a Mohr-Coulumb type yield surface in principal stress space comprises six corners and an apex that make singularity for the normal integration approach of constitutive equations. With respect to the isotropic nature of the material, a technique for processing these singularities by means of Koiter's rule, along with a transforming approach between both stress spaces for both stress tensor and consistent stiffness matrix based on spectral decomposition method, is introduced to provide such an approach for developing generalized Hardening Soil model in finite element analysis code ABAQUS. The implemented model is verified in comparison with the results after the original simulations of oedometer and triaxial tests by means of this model, for volumetric and shear hardenings respectively. Results from the simulation of oedometer test show similar shape of primary loading curve to the original one, while maximum vertical strain is a little overestimated for about 0.5% probably due to the selection of relationships for cap parameters. In simulation of triaxial test, the stress-strain and dilation curves are both in very good agreement with the original curves as well as test data.

• Journal of Intelligence and Information Systems
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• v.20 no.2
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• pp.59-71
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• 2014

System trading is becoming more popular among Korean traders recently. System traders use automatic order systems based on the system generated buy and sell signals. These signals are generated from the predetermined entry and exit rules that were coded by system traders. Most researches on system trading have focused on designing profitable entry and exit rules using technical indicators. However, market conditions, strategy characteristics, and money management also have influences on the profitability of the system trading. Unexpected price deviations from the predetermined trading rules can incur large losses to system traders. Therefore, most professional traders use strategy portfolios rather than only one strategy. Building a good strategy portfolio is important because trading performance depends on strategy portfolios. Despite of the importance of designing strategy portfolio, rule of thumb methods have been used to select trading strategies. In this study, we propose a SVM-based strategy portfolio management system. SVM were introduced by Vapnik and is known to be effective for data mining area. It can build good portfolios within a very short period of time. Since SVM minimizes structural risks, it is best suitable for the futures trading market in which prices do not move exactly the same as the past. Our system trading strategies include moving-average cross system, MACD cross system, trend-following system, buy dips and sell rallies system, DMI system, Keltner channel system, Bollinger Bands system, and Fibonacci system. These strategies are well known and frequently being used by many professional traders. We program these strategies for generating automated system signals for entry and exit. We propose SVM-based strategies selection system and portfolio construction and order routing system. Strategies selection system is a portfolio training system. It generates training data and makes SVM model using optimal portfolio. We make $m{\times}n$ data matrix by dividing KOSPI 200 index futures data with a same period. Optimal strategy portfolio is derived from analyzing each strategy performance. SVM model is generated based on this data and optimal strategy portfolio. We use 80% of the data for training and the remaining 20% is used for testing the strategy. For training, we select two strategies which show the highest profit in the next day. Selection method 1 selects two strategies and method 2 selects maximum two strategies which show profit more than 0.1 point. We use one-against-all method which has fast processing time. We analyse the daily data of KOSPI 200 index futures contracts from January 1990 to November 2011. Price change rates for 50 days are used as SVM input data. The training period is from January 1990 to March 2007 and the test period is from March 2007 to November 2011. We suggest three benchmark strategies portfolio. BM1 holds two contracts of KOSPI 200 index futures for testing period. BM2 is constructed as two strategies which show the largest cumulative profit during 30 days before testing starts. BM3 has two strategies which show best profits during testing period. Trading cost include brokerage commission cost and slippage cost. The proposed strategy portfolio management system shows profit more than double of the benchmark portfolios. BM1 shows 103.44 point profit, BM2 shows 488.61 point profit, and BM3 shows 502.41 point profit after deducting trading cost. The best benchmark is the portfolio of the two best profit strategies during the test period. The proposed system 1 shows 706.22 point profit and proposed system 2 shows 768.95 point profit after deducting trading cost. The equity curves for the entire period show stable pattern. With higher profit, this suggests a good trading direction for system traders. We can make more stable and more profitable portfolios if we add money management module to the system.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.5
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• pp.69-81
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• 2018

Recently, user participatory workshops have been applied as a way to plan landscape spaces that reflects the needs and demands of the users. It is also required to improve the quality of the FECC (Forest Experience Center for Children), which is growing rapidly. Therefore, the purpose of this study is to deduct the design elements (forest play activities and space), the basic needs, and the demands of users in making the FECC a preschooler participatory workshop. For this, materials for preschooler participation were selected, and a step-by-step workshop was conducted to satisfy the demands of the preschooler's development. First, in the pre-workshops phase, design elements standards were deducted through the preschooler participatory results (41 children aged 6 and 7, Kindergarten). Second, in the main workshop phase, the design elements to be introduced on the site (Songsan-mulbit FECC) were deducted through the participating preschooler's selection and those results were analyzed. The materials used at the preschooler participatory process were 'drawing a picture' in the pre-workshop phase, and the design elements and the standard types charts were the forest play activity pictogram chart, and the forest play space general images chart in the main workshop. As for results, frst, there are 38 standard types of forest play activities that have been deducted. It consists of 27 cognitive activities (functional 16, constructive 4, symbolic 4, game on rule 3), 9 games (sensory 5, other 4), and two social play activities (solo, group). There are 21 standard types of forest play spaces. They consist of 8 play facility spaces (5 facility, 3 natural), 2 water spaces, and 11 spaces of 5 types. Second, as a result of applying the results to the site, the forest play activities to be introduced on the site were selected, and the functional play was most selected. Additionally, climbing and water play were most selected as the unit activities. Also, functional, constructive, symbolic, games based on rules were selected, even in the preschooler's development play. In the case of the forest play spaces to be introduced in the site, the preschooler's selection results by sex and age tended to be similar to the preschooler's comprehensive selection results, but the boys preferred function and adventure spaces more than the girls, while the girls preferred rest spaces more than the boys. This result is similar to the previous study results, which directly observed the preschooler's forest play behavior, and analysis that the preschooler recognized the site and selected the design elements introduced on the site. Therefore, the participatory workshop process and the materials process in this study are analyzed and applied to the purpose of the study. It is valuable as a case to be applied in design of the FECC from this point forward.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.1
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• pp.35-45
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• 2016

Purpose: The present study was aimed to investigate the effect of corneal eccentricity on the axial rotation when wearing toric soft contact lenses were worn for certain time and changing the gaze directions. Methods: Toric soft contact lenses with double thin zone design applied on 85 of with-the-rule astigmatic eyes. Then, rotational direction and amount of contact lenses were measured after 15 minutes and 6 hours of lens wear. The difference was further compared and analyzed according to corneal eccentricity. Results: The rotation of toric lens showed a tendency to rotate to temporal direction in all gaze directions except temporal-upper direction in all groups of corneal eccentricity. The amount of lens rotation in the frontal gaze direction exhibited a negative correlation since the amount was decreased with increasing corneal eccentricity after both 15 minutes and 6 hours of lens wearing. In many cases, the cornea with small eccentricity also showed the lens rotation larger than $10^{\circ}$. The difference in rotational amount after 15 minutes of toric lens wear was small according to the corneal eccentricity however, the change of rotational amount of contact lens according to corneal eccentricity was shown after 6 hours of lens wear. Conclusions: The present study revealed that the amount of axial rotation was largely varied according to the wearer's corneal eccentricity when wearing toric lens and the rotational amount after certain time of lens was also affected by corneal eccentricity. Thus, it is suggested that the selection of toric soft contact lenses based on corneal eccentricity is necessary.

• Spatial Information Research
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• v.8 no.1
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• pp.85-99
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• 2000

Accurate information on habitat distribution of protected fauna is essential for the habitat management of Korea, a country with very high development pressure. The objectives of this study were to develop a habitat suitability model of wild boar based on GIS and logistic regression, and to create habitat distribution map, and to prepare the basis for habitat management of our country s endangered and protected species. The modeling process of this restudyarch had following three steps. First, GIS database of environmental factors related to use and availability of wild boar habitat were built. Wild boar locations were collected by Radio-Telemetry and GPS. Second, environmental factors affecting the habitat use and availability of wild boars were identified through chi-square test. Third, habitat suitability model based on logistic regression were developed, and the validity of the model was tested. Finally , habitat assessment map was created by utilizing a rule-based approach. The results of the study were as folos. First , distinct difference in wild boar habitat use by season and habitat types were found, however, no difference in wild boar habiat use by season and habitat types were found , however, ho difference by sex and activity types were found. Second, it was found, through habitat availability analysis, that elevation , aspect , forest type, and forest age were significant natural environmental factors affecting wild boar hatibate selection, but the effects of slope, ridge/valley, water, and solar radiation could not be identified, Finally, the habitat at cutoff value of 0.5. The model validation showed that inside validation site had the classification accuracy of 73.07% for total habitat and 80.00% for cover habitat , and outside validation site had the classification accuracy of 75.00% for total habitat.

• Journal of Chest Surgery
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• v.22 no.1
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• pp.134-140
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• 1989

A clinical evaluation was made on total 207 cases of corrosive esophageal stricture after ingestion of various corrosive substances and 173 cases of neoplasms in the esophagus and the cardia. The various complications associated with esophageal corrosion were observed on 28 cases [13.5%] in a total of 207 cases. Pathoanatomic findings of complication may be classified to the five category as follow; [1] stenosis in the pharynx due to adhesion of the epiglottis, [2] esophagobronchial fistula, [3] esophageal perforation with bougienation, [4] necrotic rupture of the esophagus and the stomach, and [5] so-called chronic corrosive gastritis. The comparative studies were done on a total of 165 cases of the various procedures of esophagoplasty to the reconstruction of the esophagus, which consists of antethoracal esophagoplasty with jejunum, retrosternal esophagoplasty with jejunum, retrosternal esophagoplasty with right colon, and retrosternal esophagoplasty with left colon. There is no hard and fast rule in selection of jejunum, right colon or left colon as the transplanting bowel and an operative method either antethoracal or retrosternal approach. When there was no possibility of the complication and no any defect of the anatomical states, one stage retrosternal esophagoplasty using right colon was better in various points of view. The 173 patients of the neoplasm of the esophagus consist of 28 cases of benign tumors and 145 cases of malignant tumors in the esophagus and cardia. 28 cases of benign tumors in the esophagus received the surgical treatment and they obtained with excellent results postoperatively. Of the 145 patients of esophageal carcinoma who received surgical managements, 101 cases [69.6%] were found to be operable and 44 cases [30.3%] were inoperable. Due to the various level of carcinoma in the esophagus, the following different surgical procedure was properly used case by case to get the best results in each case. Esophageal carcinoma in the upper and middle third segment received the total esophagectomy and the reconstruction of the esophagus using right colon by substernal procedure. Esophageal carcinoma in the lower third segment received an esophagojejunostomy in the mediastinum after the resection of lower third segment of the esophagus. Carcinoma in the esophago cardia and the stomach received also an esophagojejunostomy after the resection of the lower third segment of the esophagus and subtotal gastrectomy. For the 44 patients with inoperable carcinoma, the several palliative surgical managements such as gastrostomy or jejunostomy for feeding and esophagojejunostomy for bypass of the lower esophagus and the stomach were properly performed case by case for their maximum improvement.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.155-160
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• 2014

There are many image processing based algorithms and applications that fail when illumination change occurs. Therefore, the illumination change has to be detected then the illumination change occurred images need to be enhanced in order to keep the appropriate algorithm processing in a reality. In this paper, a new method for detecting illumination changes efficiently in a real time by using local region information and fuzzy logic is introduced. The effective way for detecting illumination changes in lighting area and the edge of the area was selected to analyze the mean and variance of the histogram of each area and to reflect the changing trends on previous frame's mean and variance for each area of the histogram. The ways are used as an input. The changes of mean and variance make different patterns w hen illumination change occurs. Fuzzy rules were defined based on the patterns of the input for detecting illumination changes. Proposed method was tested with different dataset through the evaluation metrics; in particular, the specificity, recall and precision showed high rates. An automatic parameter selection method was proposed for contrast limited adaptive histogram equalization method by using entropy of image through adaptive neural fuzzy inference system. The results showed that the contrast of images could be enhanced. The proposed algorithm is robust to detect global illumination change, and it is also computationally efficient in real applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.324-325
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• 2014

Quantum wells infrared photodetectors (QWIPs) have been used to detect infrared radiations through the principle based on the localized stated in quantum wells (QWs) [1]. The mature III-V compound semiconductor technology used to fabricate these devices results in much lower costs, larger array sizes, higher pixel operability, and better uniformity than those achievable with competing technologies such as HgCdTe. Especially, GaAs/AlGaAs QWIPs have been extensively used for large focal plane arrays (FPAs) of infrared imaging system. However, the research efforts for increasing sensitivity and operating temperature of the QWIPs still have pursued. The modification of heterostructures [2] and the various fabrications for preventing polarization selection rule [3] were suggested. In order to enhance optical performances of the QWIPs, double barrier quantum well (DBQW) structures will be introduced as the absorption layers for the suggested QWIPs. The DBWQ structure is an adequate solution for photodetectors working in the mid-wavelength infrared (MWIR) region and broadens the responsivity spectrum [4]. In this study, InGaAs/GaAs/AlGaAs double barrier quantum well infrared photodetectors (DB-QWIPs) are successfully fabricated and characterized. The heterostructures of the InGaAs/GaAs/AlGaAs DB-QWIPs are grown by molecular beam epitaxy (MBE) system. Photoluminescence (PL) spectroscopy is used to examine the heterostructures of the InGaAs/GaAs/AlGaAs DB-QWIP. The mesa-type DB-QWIPs (Area : $2mm{\times}2mm$) are fabricated by conventional optical lithography and wet etching process and Ni/Ge/Au ohmic contacts were evaporated onto the top and bottom layers. The dark current are measured at different temperatures and the temperature and applied bias dependence of the intersubband photocurrents are studied by using Fourier transform infrared spectrometer (FTIR) system equipped with cryostat. The photovoltaic behavior of the DB-QWIPs can be observed up to 120 K due to the generated built-in electric field caused from the asymmetric heterostructures of the DB-QWIPs. The fabricated DB-QWIPs exhibit spectral photoresponses at wavelengths range from 3 to $7{\mu}m$. Grating structure formed on the window surface of the DB-QWIP will induce the enhancement of optical responses.