• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.5
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• pp.492-501
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• 2007

Coastal disasters have become one of the most important issues in every coastal country. In Korea, coastal disasters such as storm surge, sea level rise and extreme weather have placed many coastal regions in danger of being exposed or damaged during subsequent storms and gradual shoreline retreat. A storm surge is an onshore gush of water associated with a tow pressure weather system, typically in typhoon season. However, it is very difficult to predict storm surge height and inundation due to the irregularity of the course and intensity of a typhoon. To provide a new scheme of typhoon damage prediction model, the scenario which changes the central pressure, the maximum wind radius, the track and the proceeding speed by corresponding previous typhoon database, was composed. The virtual typhoon scenario database was constructed with individual scenario simulation and evaluation, in which it extracted the result from the scenario database of information of the hereafter typhoon and information due to climate change. This virtual typhoon scenario database will apply damage prediction information about a typhoon. This study performed construction and analysis of the simulation system with the storm surge/coastal inundation model at Masan coastal areas, and applied method for predicting using the scenario of the storm surge.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.9-17
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• 2017

A high degree of precision and accuracy in Gamma Knife Radiosurgery(GKRS) is a fundamental requirement for therapeutical success. Elaborate radiation delivery and dose gradients with the steep fall-off of radiation are clinically applied thus necessitating a dedicated Quality Assurance(QA) program in order to guarantee dosimetric and geometric accuracy and reduce all the risk factors that can occur in GKRS. In this study, as a part of QA we verified the accuracy of single-shot dose profiles used in the algorithm of Gamma Knife Perfexion(PFX) treatment planning system employing Variable Ellipsoid Modeling Technique(VEMT). We evaluated the dose distributions of single-shots in a spherical ABC phantom with diameter 160 mm on Gamma Knife PFX. The single-shots were directed to the center of ABC phantom. Collimating configurations of 4, 8, and 16 mm sizes along x, y, and z axes were studied. Gamma Knife PFX treatment planning system being used in GKRS is called Leksell GammaPlan(LGP) ver 10.1.1. From the verification like this, the accuracy of GKRS will be doubled. Then the clinical application must be finally performed based on precision and accuracy of GKRS. Specifically the width at the 50% isodose level, that is, Full-Width-of-Half-Maximum(FWHM) was verified under such conditions that a patient's head is simulated as a sphere with diameter 160mm. All the data about dose profiles along x, y, and z axes predicted through VEMT were excellently consistent with dose profiles from LGP within specifications(${\leq}1mm$ at 50% isodose level) except for a little difference of FWHM and PENUMBRA(isodose level: 20%~80%) along z axis for 4 mm and 8mm collimating configurations. The maximum discrepancy of FWHM was less than 2.3% at all collimating configurations. The maximum discrepancy of PENUMBRA was given for the 8 mm collimator along z axis. The difference of FWHM and PENUMBRA in the dose distributions obtained with VEMT and LGP is too small to give the clinical significance in GKRS. The results of this study are considered as a reference for medical physicists involved in GKRS in the whole world. Therefore we can work to confirm the validity of dose distributions for all collimating configurations determined through the regular preventative maintenance program using the independent verification method VEMT for the results of LGP and clinically assure the perfect treatment for patients of GKRS. Thus the use of VEMT is expected that it will be a part of QA that can verify and operate the system safely.

• Applied Microscopy
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• v.37 no.2
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• pp.93-102
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• 2007

Secretory leukocyte protease inhibitor (SLPI) was known as one of bacterial lipopolysaccharide (LPS)-induced products of macrophage. Macrophages play an important role in the development of inflammatory responses by secreting an array of cytokines and chemokines in a tissue microenvironment. To identify the function and relationship between potent growth factors and SLPI after LPS stimulation, we conducted reverse transcriptase polymerase chain reaction (RT-PCR) and Western blots for the detection of mRNA and protein expression of SLPI and growth factors such as VEGF, PDGF, bFGF after 100 ng LPS stimulation on the RAW264.7 cells. The result of RT-PCR was showed SLPI mRNA expression was increased from 60 min to 48h in RAW 264.7 cells after incubation with LPS. VEGF and PDGF mRNA was expressed highly at initial stage by LPS stimulation. The mRNA of bFGF and type I collagen was very weakly expressed after LPS stimulation. SLPI protein level was increased likely the mRNA levels in RAW 267.7 cells. Additionally, phase contrast and scanning electron microscopic observation demonstrated that the LPS induce the change of morphology of the RAW264.7 cells. From these results, it suggest that expression of SLPI by LPS treatment may associate with VEGF and PDGF expression in RAW264.7 cells.

• Journal of the Korean Society of School Health
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• v.22 no.1
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• pp.1-16
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• 2009

Purposes: The objective of this study was to develop a management program for Korean elementary school students suffering from asthma, which would be based on the Australian Asthma-Friendly Schools (AFS) program. Methods: On the basis of the AFS program, we designed a 6-month pilot project for asthmatic students in two elementary schools in a rural area and one elementary school in an urban area of Korea. The pilot project consisted of the following processes: identifying students with asthma in a school, educating school staffs and the parents of an asthmatic child, registering those with asthma, and installing emergency kits for asthma attacks in school health rooms. In order to evaluate these processes, group discussions were held between project team members and school staffs in each area. In addition, we conducted a postal survey of 144 households having an asthmatic child. Results: The screening process adopted in this program resulted in the early diagnosis in asthma; however, it needs to be evaluated economically due to expensive diagnostic test for asthma. For the school nurses, asthma lessons were evaluated as being very helpful for their tasks, while teachers tended to take less interest in the program with only 45% of all teachers attending these lessons. Almost all participating parents reported that such lessons would be beneficial for the care of their child, even though only 24.2% of the survey respondents (122 households) attended the lessons. Installing emergency kits in school health rooms was regarded as a key feature of this project. The introduction of a register card containing more specific health records of asthmatic students was considered necessary to replace the existing list of students with asthma. Conclusion: This study has merit in that a Korean asthma-friendly schools program was developed for the first time, despite the many obstacles to such programs becoming more common.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.1
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• pp.37-47
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• 2019

Recently, due to the increase in skin diseases caused by particulate matter, endocrine disruptor and environmental changes, the trend of development of cosmetic materials has been shifting to the more safe and effective ingredients based on natural materials rather than existing synthetic compounds like steroids and antihistamines. This study aimed to develop a new natural cosmetic materials using oriental herbs such as Eucommiae cortex, Alpinia oxyphylla Miquel and Bombyx batryticatus. First, DPPH assay was performed to examine the antioxidative activity of the herbal extract (Mix) and 98.8% DPPH radical scavenging activity was confirmed at $400{\mu}g/mL$ concentration of it. In order to confirm the whitening efficacy of oriental herbal extracts(mix), the amount of melanin synthesized after stimulation of ${\alpha}-MSH$ with B16F10 cells was measured. Results showed that it was decreased to 27.1% comparing with the only ${\alpha}-MSH$ treated group, which confirmed the whitening efficacy. Also, both nitric oxide(NO) production and iNOS and COX-2 expression were significantly reduced in RAW264.7 macrophages activated by LPS in the presence of the extracts(Mix). The mRNA expression of the inflammatory cytokines such as $IL-1{\alpha}$, $IL-1{\beta}$, IL-6, and $TNF-{\alpha}$ was also analyzed to confirm the inhibition effect of the extracts on inflammation. Finally, to confirm the enhancement of skin barrier function, the expression of claudin 1 gene, a tight junction protein, was observed using human keratinocyte HaCaT cells and increased as concentration dependent manner. From these results, it is concluded that the oriental herbal extracts(Mix) containing Eucommiae cortex, Alpinia oxyphylla Miquel and Bombyx batryticatus is effective for antioxidant, anti-inflammation, skin whitening, and skin barrier and thus could be applied as a new natural cosmetic material.

• Korean Journal of Biological Psychiatry
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• v.14 no.2
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• pp.91-98
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• 2007

Objectives : Considering the impact of depressive illness on physical and mental health of both mother and fetus, specification of a treatment algorithm for depressive disorder during pregnancy is legitimated. This article provides a systemic review of treatments for depressive disorder during pregnancy and lactation. Methods : According to the search strategy of the Clinical Research Center for Depression of Korean Health 21 R & D Project, PubMed and EMBASE were searched using terms with regard to the treatment of depressive disorders during pregnancy and lactation. Reference lists of related reviews and studies were searched. In addition, relevant practice guidelines were searched using the PubMed. All identified clinical literatures were reviewed and summarized in a narrative manner. Results : Pharmacotherapy during pregnancy and lactation requires a comprehensive assessment of the risks and benefits of treatment for both mother and fetus or neonate. Recently, there is growing evidence that the use of tricyclic and selective serotonin reuptake inhibitors during pregnancy and lactation does not result in increased risks of teratogenicity. Treatment strategies are described according to the point of time of pregnancy or lactation. FDA categories for antidepressants during pregnancy and lactation are described. In addition, issues regarding to the electroconvulsive therapy and psychosocial treatment are discussed. Conclusion : The treatment option for depressive disorders during pregnancy and lactation depends on the severity of depressive illnesses of the individual patient. For mild to moderate depression, the non-pharmacological treatment should be considered first. For moderate to severe depression, pharmacotherapy should be administered in addition to the psychosocial treatment. ECT is recommended for depressive disorder of severe intensity. As the research knowledge is limited, the recommendations should based on the best judgement of psychiatrists.

• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.12-24
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• 2024

The number of pediatric coronavirus disease 2019 (COVID-19) cases worldwide are increasing compared to the early phase of the pandemic, along with highly transmissible severe acute respiratory syndrome coronavirus variant and the increase in adult COVID-19 vaccination. We conducted a rapid systematic review and meta-analysis of published randomized clinical trials (RCTs) of the COVID-19 vaccines and the observational retrospective studies on adverse events after COVID-19 vaccination in adolescents. Seventeen studies were finally included in this systematic review. Meta-analysis showed that although vaccination in adolescents was significantly effective to prevent COVID-19 infection in retrospective studies (risk ratio [RR], 0.29; 95% confidence interval [CI], 0.22-0.37; I² =100%), however the effect of preventing COVID-19 infection was lower than in RCTs (RR, 0.05; 95% CI, 0.01-0.27). In five retrospective studies, the pooled estimated proportion of participants with myocarditis and/or pericarditis was 2.33 per 100,000 of the population (95% CI, 0.97-5.61 per 100,000). Sub-group analysis with sex and vaccine doses showed that male (5.35 per 100,000) and the second dose (9.71 per 100,000) had significantly higher incidence of myocarditis and/or pericarditis than female (1.09 per 100,000) and the first dose (1.61 per 100,000), respectively. Our study showed that mRNA COVID-19 vaccines in adolescent recipients were favorable and effective against COVID-19 in RCT as well as observational studies. The safety findings of BNT162b2 vaccine in adolescents were explored and we found the difference of safety according to sex and vaccine doses. The occurrence of adverse events after mRNA COVID-19 vaccination should be monitored.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.10
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• pp.493-501
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• 2007

The imprecise real-time system provides flexibility in scheduling time-critical tasks. Most scheduling problems of satisfying both 0/1 constraint and timing constraints, while the total error is minimized, are NP-complete when the optional tasks have arbitrary processing times. Liu suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on uniprocessors for minimizing the total error. Song et at suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on multiprocessors for minimizing the total error. But, these algorithms are all off-line algorithms. In the online scheduling, the NORA algorithm can find a schedule with the minimum total error for the imprecise online task system. In NORA algorithm, EDF strategy is adopted in the optional scheduling. On the other hand, for the task system with 0/1 constraint, EDF_Scheduling may not be optimal in the sense that the total error is minimized. Furthermore, when the optional tasks are scheduled in the ascending order of their required processing times, NORA algorithm which EDF strategy is adopted may not produce minimum total error. Therefore, in this paper, an online algorithm is proposed to minimize total error for the imprecise task system with 0/1 constraint. Then, to compare the performance between the proposed algorithm and NORA algorithm, a series of experiments are performed. As a conseqence of the performance comparison between two algorithms, it has been concluded that the proposed algorithm can produce similar total error to NORA algorithm when the optional tasks are scheduled in the random order of their required processing times but, the proposed algorithm can produce less total error than NORA algorithm especially when the optional tasks are scheduled in the ascending order of their required processing times.

• Progress in Medical Physics
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• v.26 no.1
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• pp.42-51
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• 2015

In proton therapy, verification of proton dose distribution is important to treat cancer precisely and to enhance patients' safety. To verify proton dose distribution, in a previous study, our team incorporated a vertically-aligned one-dimensional array detection system. We measured 2D prompt-gamma distribution moving the developed detection system in the longitudinal direction and verified similarity between 2D prompt-gamma distribution and 2D proton dose distribution. In the present, we have developed two-dimension prompt-gamma measurement system consisted of a 2D parallel-hole collimator, 2D array-type NaI(Tl) scintillators, and multi-anode PMT (MA-PMT) to measure 2D prompt-gamma distribution in real time. The developed measurement system was tested with $^{22}Na$ (0.511 and 1.275 MeV) and $^{137}Cs$ (0.662 MeV) gamma sources, and the energy resolutions of 0.511, 0.662 and 1.275 MeV were $10.9%{\pm}0.23p%$, $9.8%{\pm}0.18p%$ and $6.4%{\pm}0.24p%$, respectively. Further, the energy resolution of the high gamma energy (3.416 MeV) of double escape peak from Am-Be source was $11.4%{\pm}3.6p%$. To estimate the performance of the developed measurement system, we measured 2D prompt-gamma distribution generated by PMMA phantom irradiated with 45 MeV proton beam of 0.5 nA. As a result of comparing a EBT film result, 2D prompt-gamma distribution measured for $9{\times}10^9$ protons is similar to 2D proton dose distribution. In addition, the 45 MeV estimated beam range by profile distribution of 2D prompt gamma distribution was $17.0{\pm}0.4mm$ and was intimately related with the proton beam range of 17.4 mm.

• Radiation Oncology Journal
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• v.24 no.3
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• pp.185-191
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• 2006

[ $\underline{Purpose}$ ]: Standardization quality assurance (QA) program of CyberKnife for suitable circumstances in Korea has not been established. In this research, we investigated the development of QA program for CyberKnife and evaluation of the feasibility under applications. $\underline{Materials\;and\;Methods}$: Considering the feature of constitution for systems and the therapeutic methodology of CyberKnife, the list of quality control (QC) was established and divided dependent on the each period of operations. And then all these developed QC lists were categorized into three groups such as basic QC, delivery specific QC, and patient specific QC based on the each purpose of QA. In order to verify the validity of the established QA program, this QC lists was applied to two CyberKnife centers. The acceptable tolerance was based on the undertaking inspection list from the CyberKnife manufacturer and the QC results during last three years of two CyberKnife centers in Korea. The acquired measurement results were evaluated for the analysis of the current QA status and the verification of the propriety for the developed QA program. $\underline{Results}$: The current QA status of two CyberKnife centers was evaluated from the accuracy of all measurements in relation with application of the established QA program. Each measurement result was verified having a good agreement within the acceptable tolerance limit of the developed QA program. $\underline{Conclusion}$: It is considered that the developed QA program in this research could be established the standardization of QC methods for CyberKnife and confirmed the accuracy and stability for the image-guided stereotactic radiotherapy.