• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10C
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• pp.967-983
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• 2003

In wireless spread-spectrum communication systems utilizing PN (pseudo noise) sequences, a variety of noise sources from the channel affect the data reception performance. Among them, in this paper we are concerned with the narrowband interference that may arise from the use of the spectral bands overlapped by the existing narrowband users or the intentional jammers as in military communication. The effect of this interference can be reduced to some extent at the receiver with the PN demodulation by processing gain. It is known, however, that when the interferers are strong, the reduction cannot be sufficient and thereby requiring the extra use of narrowband interference cancellers (NIC's) at the receivers. A class of adaptive NIC's are studied here based on different two cost functions. One is the chip mean-squared error (MSE) computed prior to the PN demodulation and used in the conventional cancellers. Since thses conventional cancellers should be operated at the chip rate, the computational requirements are enormous. The other is the symbol MSE computed after the PN demodulation in which case the weights of the NIC's can be updated at a lot lower symbol rate. To compare the performance of these NIC's, we derive a common measure of performance, i.e., the symbol MSE after the PN demodulation. The analytical results are verified by computer simulation. As a result, it is shown that the cancellation capability of the symbol-rate NIC's are similar or better than the conventional one while the computational complexity can be reduced a lot.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.1-8
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• 2000

It is required that gas accidents should be managed carefully as the consumption of fuel gas increases and high pressure gas process becomes more complex, which may cause a catastrophic accident. Factors to cause accidents were investigated through a systematic analysis of gas accidents between 1995 and 1998, which could be applied to prepare countermeasures to reduce gas accidents. As a result, it was suggested that the effective countermeasures to gas accidents should be kept applied, while new countermeasures were suggested in the field of increasing or not-decreasing number of accident. Totally 2,027 of accidents were reported during this term, and were found to decrease by about $12\%$ every year from 1996. The number of fuel gas such as LPG and city gas accident took up $96\%$, and most of accidents occurred at end-user's facility such as residential house and restaurant business. According to the kind of gas and facility, trend of accident by cause varies, while dominant causes are defective installation, appliance failure, or user's carelessness. Intentional accidents by fuel gas was excluded in this study because of its occurring mechanism and will be analyzed further elsewhere, although it took up $15\%$ and increased by $38\%$ every year.

• Journal of Chest Surgery
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• v.45 no.5
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• pp.295-300
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• 2012

Background: With growing attention to the aortopathy associated with aortic valve diseases, the number of candidates for accompanying ascending aorta and/or root replacement is increasing among the patients who require aortic valve replacement (AVR). However, such procedures have been considered more risky than AVR alone. This study aimed to compare the surgical outcome of isolated AVR and AVR combined with aortic procedures. Materials and Methods: A total of 86 patients who underwent elective AVR between 2004 and June 2010 were divided into two groups: complex AVR (n=50, AVR with ascending aorta replacement in 24 and the Bentall procedure in 26) and simple AVR (n=36). Preoperative characteristics, surgical data, intra- and postoperative allogenic blood transfusion requirement, the postoperative clinical course, and major complications were retrospectively reviewed and compared. Results: The preoperative mean logistic European System for Cardiac Operative Risk Evaluation (%) did not differ between the groups: $11.0{\pm}7.8%$ in the complex AVR group and $12.3{\pm}8.0%$ in the simple AVR group. Although complex AVR required longer cardiopulmonary bypass ($152.4{\pm}52.6$ minutes vs. $109.7{\pm}22.7$ minutes, p=0.001), the quantity of allogenic blood products did not differ ($13.4{\pm}14.7$ units vs. $13.9{\pm}11.2$ units). There was no mortality, mechanical circulatory support, stroke, or renal failure requiring hemodialysis/filtration. No difference was found in the incidence of bleeding (40% vs. 33.3%) which was defined as red blood cell transfusion ${\geq}5$ units, reoperation, or intentional delayed closure. The incidence of mediastinitis (2.0% vs. 0%), ventilator ${\geq}24$ hours (4.0% vs. 2.8%), atrial fibrillation (18.0% vs. 25.0%), mean intensive care unit stay (34.5 hours vs. 38.8 hours), and median hospital stay (8 days vs. 7 days) did not differ, either. Conclusion: AVR combined with additional aortic or root replacement showed an excellent outcome and recovery course equivalent to that after isolated AVR.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.130.2-130.2
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• 2013

Today, chemical vapor deposition (CVD) of hydrocarbon gases has been demonstrated as an attractive method to synthesize large-area graphene layers. However, special care should be taken to precisely control the resulting graphene layers in CVD due to its sensitivity to various process parameters. Therefore, a facile synthesis to grow graphene layers with high controllability will have great advantages for scalable practical applications. In order to simplify and create efficiency in graphene synthesis, the graphene growth by thermal annealing process has been discussed by several groups. However, the study on growth mechanism and the detailed structural and optoelectronic properties in the resulting graphene films have not been reported yet, which will be of particular interest to explore for the practical application of graphene. In this study, we report the growth of few-layer, large-area graphene films using rapid thermal annealing (RTA) without the use of intentional carbon-containing precursor. The instability of nickel films in air facilitates the spontaneous formation of ultrathin (<2~3 nm) carbon- and oxygen-containing compounds on a nickel surface and high-temperature annealing of the nickel samples results in the formation of few-layer graphene films with high crystallinity. From annealing temperature and ambient studies during RTA, it was found that the evaporation of oxygen atoms from the surface is the dominant factor affecting the formation of graphene films. The thickness of the graphene layers is strongly dependent on the RTA temperature and time and the resulting films have a limited thickness less than 2 nm even for an extended RTA time. The transferred films have a low sheet resistance of ~380 ${\Omega}/sq$, with ~93% optical transparency. This simple and potentially inexpensive method of synthesizing novel 2-dimensional carbon films offers a wide choice of graphene films for various potential applications.

• Journal of Korean Philosophical Society
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• v.131
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• pp.131-163
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• 2014

This Paper aims to elaborate on the origin of thinking mind. And this is a cooperative project between philosophy and neuroscience and brain science. I have written this paper in admiration for the achievements of twentieth century neuroscience and brain science, and out of desire to assist the subject in future. Much of the history of modern philosophy, from Descartes and Kant forward, consists of failed models of brain. As Edward O. Wilson precisely said, the shortcoming is not the fault of the philosophers, who have doggedly pushed their methods to the limit, but a straightforward consequence of the biological evolution of the brain. Guiding that investigation down pathways that will illuminate brain research is a task of neuroscience and brain science. Investigating logical relations among concepts is a philosophical task. If we are to understand the neural structures and dynamics that make perception, thought, intentional behaviour possible, clarity about these concepts and categories and their relations is essential. Hence our joint venture of philosophy and science. Sure, it is human beings that perceives, not parts of its brain. And it is human beings that who think and reason, not their brain. But the brain and its activities make it possible for human beings-not for it-to perceive and think, to feel emotions, and to form and pursue projects. Thus We try to investigate and reveal the origin of thinking mind as follow: 1) The difference between chimpanzee and human beings 2) brain and mind 3) the origin of thinking 4) the wisdom of nature.

• Korean Journal of Legislative Studies
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• v.23 no.1
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• pp.187-226
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• 2017

North Korea discourse is doubtful. A considerable portion is distorted under political objectives, group identity, and interests. Surely, there are facts based on North Korea's conducts. Apparent deceptions commonly exist as well though. Korean media does not endeavor to set the records straight and there are no revision towards mislead information. This is substantially dangerous as it can misjudge North Korean policies, beget national antipathy, and interferes with rational and constructive policy making. This study stems from such concerns and takes such cases as HEU(Highly Enriched Uranium) suspicion of 2002, dispute covering BDA(Banco Delta Asia)'s counterfeiting, and the abandonment of the Geneva Agreed Framework into consideration. The first part concentrates on fathoming the truth of the three cases. References from US government, academia, think tanks, media were inquired with an addition of secondary material from Korea and China. Secondly it examines whether domestic news properly reflects the precedent facts along the process of discovery. The cause and solution suggested by domestic media were organized and inductively reconstituted to frames. The last study questions the structural factors that reproduces suspicion analogs. Today's dangers facing Korean society are essentially not natural but artificial. This research hopes to foster peace by analyzing related discourses that are infamous to reinterpret reality.

• Journal of Korean Philosophical Society
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• v.144
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• pp.371-398
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• 2017

The emotions that Aristotle treats in Rhetoric II 2-11 are broadly divided into two groups: the one is the so-called basic emotions, the other the emotions that are opposed to them. The reason that he draws attention to the opposite emotions is that, for example, angry judges must be placed in an opposite state. The question is whether the calmness treated in Rhetoric II 3 is an emotion. Because it is treated in the Ethics as a virtue and thus as a trait of character. How is calmness distinguished as an emotion from that as a virtue? And in what way is it opposed to anger? In short, what is the calmness, inasmuch as it is an emotion? This is the question which is the task of this work. The thesis asserted in this paper is that calmness is the disposition to do a service for another that results from praise or some other act that enhances a belief in one's worth. To substantiate the thesis, the following questions are discussed. The first question is whether the calmness could also contain proportions of pleasure and pain. The question also arises whether it could be also treated properly according to the standard 'target person-intentional object-mental state'. Finally, there is a comparison between the concept of calmness in the Ethics and Rhetoric, so that the latter concept places itself in the foreground.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.439-447
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• 2019

The distance between the natural teeth and the implants is an important factor in preserving the periodontal tissues and esthetics. And abnormal positional displacement and tilting of the teeth during restorative procedure may require intentional root canal treatment and may affect masticatory function. This report is to present a successful full mouth rehabilitation of a patient with uneven dentition and collapsed occlusion using orthodontic and implant treatment. The patient had no symptoms or discomfort of temporomandibular joint disorder such as pain or sound. The orthodontic treatment was continued until implant provisional prosthesis delivery. And the vertical height of occlusion was elevated 2mm on anterior basis for anterior teeth protection and esthetics. After the orthodontic treatment, the implant abutments and natural teeth were finally restored with porcelain-fused-to-metal crowns and bridges. Satisfactory function and esthetic outcomes are observed after 6months of follow up.

• Journal of The Korean Society of Clinical Toxicology
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• v.17 no.2
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• pp.108-117
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• 2019

Purpose: The study examined the poisoned patients' characteristics nationwide in Korea by using data from the National Emergency Department Information System (NEDIS). Methods: Among the patients' information sent to NEDIS from January 1, 2013 to December 31, 2015, the included subjects' main diagnosis in ED showed poisoning according to the 7th edition of the Korean Standard Disease Classification (KCD-7). We analyzed the patients' gender, age, initial vital signs, visit time, stay time of staying in ED, results of ED care, main diagnosis in ED, length of hospitalization, and results of hospitalization. Results: A total of 106,779 ED visits were included in the analysis. There were 55,878 males (52.3%), which was more than the number of females. The number of intentional poisoning was 49,805 (59.6%). 75,499 cases (70.8%) were discharged, and 25,858 cases (24.2%) were hospitalized. The numbers of poisoning patients per 1,000 ED visits were 14 in Chungnam and 11.9 in Jeonbuk. The most common cause of poisoning, according to the main diagnosis, was venomous animals. It was the same for hospitalized patients, and pesticide was next. Pesticide was the most common cause of mortality in ED (228 cases, 46.1%) and after hospitalization (584 cases, 54.9%). The incidence of poisoning by age group was frequent for patients in their 30s to 50s, and mortality in ED and post-hospitalization were frequent for patients in their 60s to 80s. Conclusion: This study investigated the characteristics of poisoning patients reported in the past 3 years. Pesticide poisoning had a high mortality rate for patients in ED and in-hospital. For mortality, there was a high proportion of elderly people over 60. Thus, policy and medical measures are needed to reduce this problem. Since it is difficult to identify the poison substance in detail due to nature of this study, it is necessary to build a database and monitoring system for monitoring the causative substance and enacting countermeasures.

• Journal of Navigation and Port Research
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• v.43 no.3
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• pp.172-178
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• 2019

Although the needs for providing resilient PNT information are increasing, threats due to the intentional RFI or space weather change are challenging to resolve. eLoran, which is a terrestrial navigation system that use a high-power signal is considered as a best back-up navigation system. Depending on the user's environment in the eLoran system, the user may use one of E-field or H-field antennas. H-field antenna, which has no restriction on setting stable ground and is relatively resistant to noise of general electronic equipment, is composed of two loops, and shows anisotropic gain pattern due to the different measurement at the two loops. Therefore, the H-field antenna's phase estimation value of signal varies depending on its direction even at the static environment. The error due to the direction of the signal should be eliminated if the user want to estimate the own position more precisely. In this paper, a method to compensate the error according to the geometric distribution between the H-field antenna and the transmitting station is proposed. A model was developed to compensate the directional error of H-field antenna based on the signal generated from the eLoran signal simulator. The model is then used to the survey measurement performed in the land area and verify its performance.