• Journal of the Korean Wood Science and Technology
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• v.28 no.2
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• pp.10-18
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• 2000

Nondestructive testing(NDT) by using ultrasonic sound is widely applied to wood for grading, moisture and defect detecting, estimating degree of decay, etc. Before practicing such application, basic relationships between ultrasonic transmission and wood properties shall be studied first. In this study, ultrasonic NDT was applied to larch and red pine to investigate the effects of moisture content and slope of grain on ultrasonic transmission speed. Specimens for testing about moisture content were prepared to have moisture content of green state, 30%, 20%, 10% and oven-dry state. Specimens for testing about slope of grain were prepared to have grain angle of 0, 15, 30, 45, 60, 75 and 90 degree in the tangential direction. Ultrasonic transmission speed was inversely proportional to moisture content in low range of moisture content under around 30% that was considered to be close to fiber saturation point. In high moisture content range above 30%, the ultrasonic transmission speed was almost constant. The same trend was observed in the relationships between compressive strength and moisture content. Slope of grain also had inversely proportional relationship with ultrasonic transmission speed and compressive strength. The relationship between compressive strength and ultrasonic transmission speed could be expressed by a linear equation.

• Korean Journal of Materials Research
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• v.9 no.3
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• pp.327-332
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• 1999

The recovery activation energy, the order of reaction and the recovery rate constant were detemined by isochronal and isothermal annealing treatment to investigate the recovery behaviors of neutron irradiated Mn-Mo-Ni low alloy steels$(fluence: 2.3\times10^{19}ncm^{-2}, 553K, E\geq1.0 MeV)$. Vickers microhardness tests were conducted to trace the recovery behavior after heat treatments. The results were analyzed in terms of recovery stages, behavior of responsible defects and recovery kinetics. It was shown that recovery occurred through two annealing stages(stage I : 703-753K, stage n : 813-873K) with re$\infty$very activation energies of 2.5 eV and 2.93 eV for each stage I and n, respectively. From the comparison of unirradiated and irradiated isochronal anneal curves, a radiation anneal hardening(RAH) peak was identified at around 813K. Most of recovery have occurred during about 120 min irrespective of isothermal annealing temperatures of 743K and 833K. Recovery rate constants were determined to be $3.4\times10^{-4}min^{-1} and 7.1\times10^{-4}min^{-1}$ for stage I and II, respectively. The order of reaction was about 2 for both recovery stages. Comparing the obtained data with those of previously reported results on neutron irradiated Mn- Mo- Ni steels, the thermal recovery be­havior of the present material seems to occur by the dissociation of point defect clusters formed during irradiation, and by the recombination process of self-interstitials and vacancies from dissociated vacancy clusters.

• The Journal of Art Theory & Practice
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• no.5
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• pp.7-24
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• 2007

The subject is connected with a structure named "The Symbolic" to Lacan, but he denied that the subject is explained simply as a fruit of language and "Other". From his point of view, passing through Subject, De-formation and Crack over it is designated as foundation of generation and creation rather than our destined defect. It should not be understood that subject of "The Real" is a concept of the subject free itself from restraint of "The Symbolic". However, this does not mean he asserts "Subject" is something incapable of being controlled by the unknown power. The problem is that this autonomous existence meets inside of it with something "more than one's own self" by "circulating around itself" like a permanent star. This is the indication of a "stranger in the middle of my privacy", or "extimit$\'{e}$", a coined-word by Lacan. Perhaps "Subject" is nothing more than the name of distance of object which is "too hot" to come close, and of this circulating movement. It's because of this object that the real subject stands against generalization and the subject can't be restored to any place in symbolic order-even though it is empty. The part which is told from Lacan's structural theory, that is to say, an importance to Lacan is that his Subject theory is not suggested or denied as a manual structure. On the contrary, it is a study of the relationship between the settled symbol that included in "real subject which is a unconscious one" and the symbolic subject hold- that is a metaphysical subject in general meaning. In Lacan's enlarged concept of subject beyond symbolic reality, it is noticeable that it gives justifiability to the union of a medium of different nature in artistic expression. We can recognize that the unconscious world is a living space which enables it to be a "condition of human being", not something dark under the surface of water through Magritte's(Rene Magritte, 1898~1967) surrealistic works. In other words, Magritte's art secures a core dimension of human nature through a mysterious gap of conscious and settled space. Magritte's drawings often evokes strange and unsettling feelings in people who view his paintings. This is because routine objects are found in "unsuitable" places from which we usually find them in our everyday lives. "Reality" in Magritte's paintings makes it aware that it is a strained field of concealment and disclosure basically between truths, and we can learn that his behavior to overturn to paint in-visible things is finally an effort to restore the "real subject" to the viewer's reality. In other words, such reversion arouses a nostalgic desire for the objects existing in their original appearance as they are - natural condition that our gaze had not been distorted yet by anamorphic stains. - and the state when we are conscious of them normally. Such desire offers an opportunity for us to get out of mental depression rather than operates to us as an abnormal crack. It's a successive process of effort to search for lost subject and Paradise Lost facing up to reality of subject human that is to be a subject of world and life are ousted from their place by structure and authority of culture.

• Journal of Korean Theatre Studies Association
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• no.40
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• pp.307-344
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• 2010

Cultural Studies built on the critical mind of New Left exposes the relationship between culture and power, and investigates how this relationship develops the cultural convention. It has achieved the new perspective that could make us to think culture and art in terms of political correctness. However, the critical voices against the theoretical premises of Cultural Studies have been increased as its heyday in 1980s was nearly over. For instance, Terry Eagleton, a former Marxist literary critic, declared in 2003 that the golden age of cultural theory is long past. This essay, therefore, intends to show the weak foundations on which the approaches of cultural studies to theatre rest and to clarify the general problem of their introduction to theatre studies. The approach of cultural studies to theatre takes the form of 'top-down inquiry' as it applies a theory to a particular play or historical period. In other word, from the theory the writer moves to the particular case. The result is not an inquiry but rather a demonstration. This circularity can destroy the point of serious intellectual investigation as the theory dictates answers. The goal-oriented narrow viewpoint as a logical consequence of 'top-down inquiry' makes the researcher to favor the plays or the parts of a play that are proper to test a theory. As a result it loses the fair judgment on the artistic value of a play, and brings about the misinterpretation. The interpreter-oriented reading is the other defect of cultural studies as it disregards the inherent meaning of the text, distorting a play. The approach of cultural studies also consists of a conventionality as it arrives at a stereotyped interpretation by using certain conventions of reasoning and rhetoric. The cultural theories are fundamentally the 'outside theories' that seek to explain not theatre but the very broad features of society and politics. Consequently their application to theatre risks the destructive criticism, disregarding the inherent experience of theatre. Most of, if not all, cultural theories, furthermore, are proven to be lack of empirical basis. The alternative method to them is a 'cognitive science' that proves scientifically our mind being influenced by bodily experience. The application of cultural materialism to Shakespeare's is one of the cases that reveal the limits of cultural studies. Jonathan Dollimore and Water Cohen provide a kind of 'canonical study' in this application that is imitated by the succeeding researchers. As a result the interpretation of has been flooded with repetitive critical remarks, revealing the problem of 'top-down inquiry' and conventional reasoning. Cultural Studies is antipodal to theatre in some respect. It is interested chiefly in the social and political reality while theatre aims to create the fiction world. The theatre studies, therefore, may have to risk the danger of destroying its own base when it adopts cultural studies uncritically. The different stance between theatre and cultural theories also occurs from the opposition of humanism vs. antihumanism. We have to introduce cultural theories selectively and properly not to destroy the inherent experience and domain of theatre.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.174-192
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• 2021

The LIDAR sensor, which provides higher cognitive performance than cameras and radar, is difficult to apply to ADAS or autonomous driving because of its high price. On the other hand, as the price is decreasing rapidly, expectations are rising to improve existing autonomous driving functions by taking advantage of the LIDAR sensor. In level 3 autonomous vehicles, when a dangerous situation in the cognitive module occurs due to a sensor defect or sensor limit, the driver must take control of the vehicle for manual driving. If the driver does not respond to the request, the system must automatically kick in and implement a minimum risk maneuver to maintain the risk within a tolerable level. In this study, based on this background, a LIDAR-based LKS MRM algorithm was developed for the case when the normal operation of LKS was not possible due to troubles in the cognitive system. From point cloud data collected by LIDAR, the algorithm generates the trajectory of the vehicle in front through object clustering and converts it to the target waypoints of its own. Hence, if the camera-based LKS is not operating normally, LIDAR-based path tracking control is performed as MRM. The HAZOP method was used to identify the risk sources in the LKS cognitive systems. B, and based on this, test scenarios were derived and used in the validation process by simulation. The simulation results indicated that the LIDAR-based LKS MRM algorithm of this study prevents lane departure in dangerous situations caused by various problems or difficulties in the LKS cognitive systems and could prevent possible traffic accidents.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.74-79
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• 2022

In this study, the plasma corrosion resistance and the change in the number of contamination particles generated using the plasma etching process and cleaning process of coating parts for semiconductor plasma etching equipment were investigated. As the coating method, atmospheric plasma spray (APS) was used, and the powder materials were Y₂O₃ and Y₃Al₅O₁₂ (YAG). There was a clear difference in the densities of the coatings due to the difference in solubility due to the melting point of the powdered material. As a plasma environment, a mixed gas of CF₄, O₂, and Ar was used, and the etching process was performed at 200 W for 60 min. After the plasma etching process, a fluorinated film was formed on the surface, and it was confirmed that the plasma resistance was lowered and contaminant particles were generated. We performed a surface cleaning process using piranha solution(H₂SO₄(3):H₂O₂(1)) to remove the defect-causing surface fluorinated film. APS-Y₂O₃ and APS-YAG coatings commonly increased the number of defects (pores, cracks) on the coating surface by plasma etching and cleaning processes. As a result, it was confirmed that the generation of contamination particles increased and the breakdown voltage decreased. In particular, in the case of APS-YAG under the same cleaning process conditions, some of the fluorinated film remained and surface defects increased, which accelerated the increase in the number of contamination particles after cleaning. These results suggest that contaminating particles and the breakdown voltage that causes defects in semiconductor devices can be controlled through the optimization of the APS coating process and cleaning process.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.193-200
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• 2022

In this study, the finite-failure NHPP software reliability model was applied to the software development model based on the Weibull lifetime distribution (Goel-Okumoto, Rayleigh, Type-2 Gumbe), which is widely used in the software reliability field, and then the cost attributes were compared and evaluated. For this study, failure time data detected during normal operation of the software system were collected and used, the most-likelihood estimation (MLE) method was applied to the parameter estimation of the proposed model, and the calculation of the nonlinear equation was solved using the binary method. As a result, first, in the software development model, when the cost of testing per unit time and the cost of removing a single defect increased, the cost increased but the release time did not change, and when the cost of repairing failures detected during normal system operation increased, the cost increased and the release time was also delayed. Second, as a result of comprehensive comparative analysis of the proposed models, it was found that the Type-2 Gumble model was the most efficient model because the development cost was lower and the release time point was relatively faster than the Rayleigh model and the Goel-Okumoto basic model. Third, through this study, the development cost properties of the Weibull distribution model were newly evaluated, and the analyzed data is expected to be utilized as design data that enables software developers to explore the attributes of development cost and release time.

• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.157-168
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• 2009

In this paper, a photovoltaic system is designed with a step up chopper and single phase PWM(Pulse Width Modulation) voltage source inverter. Where proposed Synchronous signal and control signal was processed by one-chip microprocessor for stable modulation. The step up chopper operates in continuous mode by adjusting the duty ratio so that the photovoltaic system tracks the maximum power point of solar cell without any influence on the variation of insolation and temperature because solar cell has typical voltage and current dropping character. The single phase PWM voltage source the inverter using inverter consists of complex type of electric power converter to compensate for the defect, that is, solar cell cannot be developed continuously by connecting with the source of electric power for ordinary use. It can cause the effect of saving electric power. from 10 to 20[%]. The single phase PWM voltage source inverter operates in situation that its output voltage is in same phase with the utility voltage. In order to enhance the efficiency of photovoltaic cells, photovoltaic positioning system using sensor and microprocessor was design so that the fixed type of photovoltaic cells and photovoltaic positioning system were compared. In result, photovoltaic positioning system can improved 5% than fixed type of photovoltaic cells. In addition, I connected extra power to the system through operating the system voltage and inverter power in a synchronized way by extracting the system voltage so that the phase of the system and the phase of single-phase inverter of PWM voltage type can be synchronized. And, It controlled in order to provide stable pier to the load and the system through maintaining high lurer factor and low output power of harmonics.

• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.155-165
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• 2000

Background: The phagolysosomal function of alveolar macrophage against M. tuberculosis infection is influenced by Nramp1, which is encoded by the NRAMP1 gene. There are several genetic polymorphisms in NRAMP1, and these polymorphisms affect the innate host resistance through the defect in production and function of Nramp1. To investigate this relationship, the NRAMP1 genetic polymorphism in patients with primary tuberculous pleurisy was determined. Methods: Fifty-six primary tuberculous pleurisy patient, who were diagnosed by pleural biopsy, were designated to the pleurisy group and 45 healthy adults were designated to the healthy control group. Three genetic polymorphisms of NRAMP1, such as a single point mutation in intron 4(469+14G/C, INT4), a nonconservative single-base substitution at codon 543 that changes aspartic acid to asparagine(D543N) and a TGTG deletion in the 3' untranslated region(1729+55delI4, 3'UTR), were determined. Polymerase chain reaction(PCR) and polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) were used. Results: The frequencies of mutant genotypes of INT4 and 3'UTR were significantly high in pleurisy group(p=0.001, p=0.023). But the frequencies of D543N were not significantly different between the two groups(p=0.079). The odds ratios, which are a comparison with wild genotype for determining mutant genotypes, were 8. 022(95% confidence interval=2.422-26.572) for INT4 and 5.733(95% confidence interval = 1.137~28.916) for 3'UTR ; these were statistically significant But the ratio for D543N was not significant In the combined analysis of the INT4 and 3'UTR polymorphisms, the odds ratios were 6.000(95% confidence interval = 1.461~24.640) for GC/++ genotype and 14.000(95% confidence interval=1.610~121.754) for GC/+del when compared with GG/++ homozygotes ; these were statistically significant. Conclusion: Among the NRAMP1 genetic polymorphisms, a single point mutation in intron 4(469+14G/C, INT4) and a TGTG deletion in the 3' untranslated region(1729+55del4, 3'UTR) were closely related to the primary tuberculous pleurisy.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.259-265
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• 1998

Purpose: We studied early rest/24 hour delay T1-201 perfusion SPECT for prediction of wall motion improvement after reperfusion in patients with acute myocardial infarction. Materials and Methods: Among 17 patients (male/female= 11/6, age: $59{\pm}13$) with acute myocardial infarction, 15 patients were treated with percutaneous transcoronary angioplasty (direct:2, delay: 11) and intravenous urokinase (2). Spontaneous resolution occurred in infarct-related arteries of 2 patients. We confirmed TIMI 3 flow of infarct-related artery after reperfusion in all patients with coronary angiography. We performed rest T1-201 perfusion SPECT less then 6 hours after reperfusion and delay T1-201 perfusion SPECT next day. T1-201 uptake was visually graded as 4 point score from normal (0) to severe defect (3). Rest T1-201 uptake ${\le}2$ or combination of rest T1-201 uptake ${\le}2$ or late reversibility were considered to be viable. Myocardial wall motion was graded as 5 point score from normal (1) to dyskinesia (5). Myocardial wall motion was considered to be improved when a segment showed an improvement ${\ge} 1$ grade in follow up echo compared with the baseline values. Results: Among 98 segments with wall motion abnormality, the severity of myocardial wall motion decrease was as follow: mild hypokinesia: 18/98 (18%), severe hypokinesia: 28/98 (29%), akinesia: 51/98 (52%), dyskinesia: 1/98 (1%). The wall motion improved in 85%. Redistribution (13%), and reverse redistribution (4%) were observed in 24 hour delay SPECT. Positive predictive value (PPV) and negative predictive value (NPV) of combination of late reversibility and rest T1-201 uptake were 99%, and 54%. PPV and NPV of rest T1-201 uptake were 100% and 52% respectively. Predictive values of combination of rest T1-201 uptake and late reversibility were not significantly different compared with predictive values of rest T1-201 uptake only. Conclusion: We conclude that early T1-201 perfusion SPECT predict myocardial wall motion improvement with excellent positive but relatively low negative predictive values in patients with acute myocardial infarction after reperfusion.