• Geophysics and Geophysical Exploration
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• v.23 no.2
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• pp.72-88
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• 2020

Recent rapid advances in computer hardware performance have led to relatively low computational costs, increasing the number of applications of machine-learning techniques to geophysical problems. In particular, deep-learning techniques are gaining in popularity as the number of cases successfully solving complex and nonlinear problems has gradually increased. In this paper, applications of seismic data denoising methods using deep-learning techniques are introduced and investigated. Depending on the type of attenuated noise, these studies are grouped into denoising applications of coherent noise, random noise, and the combination of these two types of noise. Then, we investigate the deep-learning techniques used to remove the corresponding noise. Unlike conventional methods used to attenuate seismic noise, deep neural networks, a typical deep-learning technique, learn the characteristics of the noise independently and then automatically optimize the parameters. Therefore, such methods are less sensitive to generalized problems than conventional methods and can reduce labor costs. Several studies have also demonstrated that deep-learning techniques perform well in terms of computational cost and denoising performance. Based on the results of the applications covered in this paper, the pros and cons of the deep-learning techniques used to remove seismic noise are analyzed and discussed.

• Journal of Ship and Ocean Technology
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• v.5 no.3
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• pp.1-13
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• 2001

Present-day rules and regulations for the design and construction of ships are almost without exemption of a prescriptive and deterministic nature. Often it is argued that this situation is far from ideal; it does no right to the advances, which have been made during the past decades in engineering tools in marine technology, both in methodology and in computational power. Within IMO this has been realized for some time and has resulted in proposals to use Formal Safety Assessment(FSA) as a tool to improve and to modernize the rule making process. The present paper makes use of elements of the FSA methodology, but instead of working towards generic regulations or requirements, a Risk Assessment Approach, not unlike a 'safety case'; valid for a certain ship or type of ship is worked out. Delft University of Technology investigated the application of safely assessment procedures in ship design, in co-operation with Anthony Veder Shipowners and safety experts from Safely Service Center BV. The ship considered is a semi-pressurized-fully refrigerated LPG carrier. On the basis of the assumption that a major accident occurs, various accident, scenarios were considered and assessed, which would impair the safety of the carrier. In a so-called Risk Matrix, in which accident frequencies versus the consequence of the scenarios are depicted, the calculated risks all appeared lo be in the ALARP('as low as reasonable practicable') region. A number of design alternatives were compared, both on safety merits and cost-effectiveness. The experience gained with this scenario-based approach will be used to establish a set of general requirements for safety assessment techniques in ship design. In the view that assessment results will be most probably presented in a quasi-quantified manner, the requirements are concerned with uniformity of both the safety assessment. These requirements make it possible that valid comparison between various assessment studies can be made. Safety assessment, founded on these requirements, provides a validated and helpful source of data during the coming years, and provides naval architects and engineers with tools experience and data for safety assessment procedures in ship design. However a lot of effort has to be spent in order to make the methods applicable in day-to-day practice.

• Spatial Information Research
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• v.5 no.2
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• pp.161-175
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• 1997

In spite of intense advances in the economy and technological progress which include massive and high-rise developments, landscape resources have either been destroyed or left to deteriorate. In recent years, efforts towards landscape management have emerged in the form of legislation and policies. However, relevant computer tools have unfortunately been insufficient in the field of landscape management. In addition, although there has been much research conducted for urban landscape management, pertinent information has not been recorded or managed efficiently. Therefore, this study developed a Landscape Information System for the purpose of managing urban landscape infOlmation and analyzing visual impacts in relation to urban development projects. Main functions of the Landscape Information System consist of the following: inputting and managing the attribute data as well as graphic data, querying attributes of urban landscape, and analyzing landscape impacts of developments. A case study was conducted for downtown Seoul. Using the system, a series of visual impact analyses were implemented at major viewpoints in the area. The results have shown that valuable landscape resources could be damaged by proposed development projects. Thus, the Landscape Information System developed in this study can be used as a major tool to manage urban landscape information efficiently and as the basis for decision-making regarding landscape simulation and visual impact analysis.

• Advances in Traditional Medicine
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• v.4 no.2
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• pp.104-111
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• 2004

Sasang Constitutional Medicine is a major branch of Korean Traditional Oriental Medicine. The differences of disease susceptibility to be shown in Sasang constitution may be due to genetic factors. Therefore, we examined interrelationship among cerebral infarction (CI), apolipoprotein E (apoE) gene polymorphism, and Sasang constitutional classification. ApoE is a key protein modulating the highly atherogenic apoB containing lipoproteins and is a candidate gene for the development of coronary artery disease (CAD). The ${\varepsilon}2\;and/or\;{\varepsilon}4$ alleles were the first to be implicated in premature CAD, which resulted in this polymorphism being extensively studied. We investigated the association between apoE genotype and CI by case-control study in a Korean population. We also classified CI patients and control group into groups according to Sasang Constitutional Medicine. 196 CI patients and 379 controls without CI were examined. ApoE genotype was determined by 8% polyacrylamide gel separation after DNA amplification. A significant difference in the apoE genotype distribution was observed in the CI patients compared with that in controls ($X^{2}$=14.920, df=4, P=0.005). Also, the frequency of Taeumin constitution in patients with CI was significantly higher than that in controls (58.0% vs. 36.9%; P<0.001). However, the Taeumin constitution did not enhance the relative risk for CI in the subjects with apoE ${\varepsilon}2\;and/or\;{\varepsilon}4$ alleles. No differences in the apoE genotypes frequencies were observed in the Taeumin compared with that in the other constitutions. In addition, we investigated whether the DD genotype of angiotensin converting enzyme (ACE) gene, a candidate gene for CI, was associated with CI, Taeumin constitution, and apoE polymorphism. As a result, the frequency of Taeumin constitution was significantly higher in CI patients with both apoE ${\varepsilon}3/{\varepsilon}4$ and ACE ID/DD genotypes than in the remaining Sasang constitutions (14.5% vs. 8.3% and 0%) ($X^{2}$=13.521, df=6, P=0.035). In summary, we concluded that the apoE polymorphism is a major risk factor for CI in Koreans and the ACE ID/DD genotype enhanced the relative risk for CI in the subjects with apoE ${\varepsilon}3/{\varepsilon}4$ genotype and Taeumin constitution.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.5 no.1
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• pp.28-35
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• 1994

Research on biological aspects on adult depression has been subjected to more than 25 years of systematic research, while biologic investigations regarding childhood and adolescent depression are only now being initiated. Although no unifying, explanatory theory of the biologic etiology of childhood depression emerges from the results of studies reviewed above, the findings do support that biological factors may be involved in the genesis of childhood depression. The research reviewed in this paper suggests that age and pubertal factors have major effects in most biological markers of depression. Some of these markers, like sleep EEG and neuroendocrine markers should be broken down by decades during adult life span. Thus, although adult data are very valuable points of departure for biological research on child and adolescent depression, it is very hard to transfer the adult data to prepubertal children and adolescents, ignoring the biological changes that take place in growth and development, pubety and aging. A great deal of work in basic developmental neuroscience remains to be done. It will be crucial for further advances in this field to determine the normal patterns of neurotransmitter interaction in this age group and to study children at high risk for depression. It will be also crucial to use primate models of depressive illness in order to be able to answer the many queations that cannot be investigated in humans for ethical issues. Conclusively, much closer collaboration between developmental and neurobiological and behavioral studies in primates and in humans will be essential for further development.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.27 no.4
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• pp.236-266
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• 2016

Attention-deficit hyperactivity disorder (ADHD) is one of the most common childhood psychiatric conditions. In 2007, the Korean Academy of child and Adolescent Psychiatry developed Korean ADHD practice parameter. Advances in the scientific evidence of ADHD caused practice parameter to be modified and updated. The present guidelines developed by ADHD translational research center summarize current literature for the treatment of ADHD in children and adults. This parameter includes the clinical evaluation for ADHD, comorbid conditions associated with ADHD, clinical feature and course, research on the etiology of the disorder, and psychopharmacological and non-pharmacological treatments for ADHD.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.3
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• pp.11-20
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• 2015

Fire incidents, which occur every year, cause huge damage to properties and humans. Significant time and costs have been invested in minimizing and responding to such accidents. With the recent advances in the development of spatial information, in the firefighting field, studies have been conducted to effectively bring fires under control using GIS(Geographic Information System). Most of such studies, however, focused on individual analyses of firefighting-related factors, but comprehensive research on the vulnerability factors in fire control activities, a major part of firefighting activity, has yet to be done. This study sought to pinpoint and analyze the factors that obstruct fire controlling, and to gather relevant data and create GIS-based databases. Based on such database, GIS-based overlay analysis was conducted to produce a fire control vulnerability map. The findings of this study will enable a quantitative analysis of firefighting obstruction factors to assist the personnel engaging in firefighting in rational decision-making, such as in formulating a firefighting operation plan for securing golden time.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.4
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• pp.306-311
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• 2005

Despite advances in surgery, radiotherapy, and chemotherapy, the survival of patients with oral squamous cell carcinoma has not significantly improved over the past several decades. Gene therapy is currently under investigation and shows us new possibility of cancer curing method. This experiment was undergone to find out the cell growth inhibition effect and evidence of apoptosis by HCCS-1(human cervical cancer suppressor-1), one of the candidates of tumor suppressor gene, transducted to human oral cancer cell line. To determine the efficiency of the adenovirus as a gene delivery vector cell line was transducted with LacZ gene and analysed with X-gal staining. Northern blot was performed to confirm the transfection with HSCC-1 gene and cell viability was assessed by cell cytotoxicity assay using cell count kit(CCK). To show the evidence of apoptosis, DNA fragmentation assay and flow cytometry(FACS) were performed. We had successfully construct the recombinant HSCC-1 adenovirus(Ad5CMV-HCCS-1), and importation efficiency was 20% at 2 MOI(multiplicity of infection), 80% at 20 MOI. Northern blot analysis showed that a single 0.6kb mRNA transcript was expressed in Ad5CMV-HCCS-1 transducted cell lines. As a result of CCK, when comparing to control subjects, transducted group showed 50% growth inhibition. In DNA fragmentation assay, according to increasing of MOI, DNA volume was diminished. In FACS analysis, DNA distribution showed fragmentation. This results imply that HCCS-1gene has growth inhibition effect in human oral cancer cell lines through apoptosis induction.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.89-112
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• 2002

The earliest reports of the use of electrical energy to directly stimulate bone healing seem to be in 1853 from England, the techniques involved the introduction of direct current into the non-united fracture site percutaneously via metallic needles, with subsequent healing of the defect. One endpoint of the periodontal therapy is to generate structure lost by periodontal diseases. Several procedural advances may support regeneration of attachment, however, regeneration of alveolar bone does not occur consistently. Therefore, factors which stimulate bone repair are areas for research in periodontal reconstructive therapy. Effects of cytokines or growth factors on bone repair are examples of such areas. Another one is electrical current which occurs in bone naturally, so that such bone may be particularly susceptible to electrical therapy. The purposes of this study were to observe the effects of electrical stimulation on the normal periodontium, to determine whether the electricity is the useful means for periodontal regeneration or not. Forty rats weighted about 100 gram were used and divided into 4 groups, the first group, there was no electrical stimulation with the connection of electrodes only. In the second group, there was stimulated by the 10 mA during 10 minutes per a day, in the third group was stimulated by the 25 mA , and the fourth by the 50 mA. At 3, 5, 10 and 15 days post-appliance , two rats in each group were serially sacrificed. and the maxillae and the mandible processed to paraffin, and the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows : 1. There was the distinct reversal line on the lingual alveolar crest, whereas a little changes in the labial alveolarcrest to the duration and amount of currents. 2. In 50 mA group, the cells were highly concentrated at the apex of anterior teeth, and was observed the necrotic tissue. In posterior root apex, the hypercementosis was appeared, and newly formed cementum layer has been increased continuously with the time. 3. The periodontal ligament fiber and Sharpey's fiber were arranged in order, and the bone trabeculae were increased as the experiment proceeded by, relatively the bone marrows were decreased. 4. In the pulp tissue, the blood vessels were increased with blood congestion in the experimetal specimens remarkably, and the dentinal tubules were obstructed . 5. The osteoblasts in alveolar bone proper had been showed highly activity, and also observed the formation of bone trabeculea. In the conclusion, it was suggested that the electrical stimulation has influence on the periodontium and the pulp tissue. However, there might be the injurious effects.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.139-145
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• 2005

Gastric cancer is the most prevalent cancer in Korea and comprises the second cause of cancer death. Surgery only can provide chance of cure, but most locally advanced cancers recur after a curative resection, even though important advances in the surgical and nonsurgical treatments of gastric cancer have taken place. Preoperative chemotherapy theoretically can provide the advantages of reducing the bulk of tumor, which might improve the R0 resection rate, and of treating micrometastases early. Also, preoperative chemotherapy is expected to render unresectable tumors resectable without increasing postoperative morbidity and mortality. There are many new chemo-therapeutic agents available for the treatment of advanced gastric cancer, but still the most effective agent, the optimal time and number of cycle for administration are still not known. The addition of postoperative chemotherapy through an intraperitoneal route and/or radiotherapy might affect the outcome of surgery favorably, but that hasn't been proved yet. A multicenter prospective randomized phase III trial should be peformed to answer for those questions and to improve the curability of gastric cancer treatment.