• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.1930-1939
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• 2015

Wind power planning aims to locate and size wind farms optimally. Traditionally, wind power planners tend to choose the wind farms with the richest wind resources to maximize the energy benefit. However, the capacity benefit of wind power should also be considered in large-scale clustered wind farm planning because the correlation among the wind farms exerts an obvious influence on the capacity benefit brought about by the combined wind power. This paper proposes a planning model considering both the energy and the capacity benefit of the wind farms. The capacity benefit is evaluated by the wind power capacity credit. The Ordinal Optimization (OO) Theory, capable of handling problems with non-analytical forms, is applied to address the model. To verify the feasibility and advantages of the model, the proposed model is compared with a widely used genetic algorithm (GA) via a modified IEEE RTS-79 system and the real world case of Ningxia, China. The results show that the diversity of the wind farm enhances the capacity credit of wind power.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.4
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• pp.61-66
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• 2004

The objective of the present study is to develop methodology for the assessment of combustion stability of liquid rocket injectors. To simulate actual combustion occurring inside of a thrust chamber, a fullscale injector has been employed in the study, which bums gaseous oxygen and mixture of methane and propane. The main idea of the experiment is that the mixing mechanism is considered as a dominant factor significantly affecting combustion instability in a fullscale thrust chamber. A single split triplet injector has been used with an open-end cylindrical combustion chamber. The characteristics revealed by excited dynamic pressures in gaseous combustion show degrees of relative acoustic damping depending on operating conditions. Upon test results, the direct comparison between various types of injectors can be realized for the selection of the best design among prospective injectors.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.2
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• pp.131-138
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• 1989

The present study was designed to develop a new method for the determination of estrogen receptor in porcine uterus using frozen sections. Cryostat sections were incubated with $^3H$-estradiol($^3H$-$E_2$) in the presence or absence of diethylstilbestrol(DES) and the radioactivity of 3H-E2 bound to estrogen receptor(ER) was detected. The level of specific estrogen receptor was determined by Scatchard analysis. The highest ratio of specific binding against total binding was achieved in 3 sec. tions(5mm x 5mm) which was corresponded to lOO${\mu}$/ml protein concentration. Optimal binding was obtained during incubation with $^3H$-$E_2$ for 30 minutes at 23$^{\circ}C$ after treatment of sections with acetone for 20 seconds. Three time-washing of sections was proved to be appropriate for the removal of unbound 3H-E2. 200-fold molar excess of DES was substituted for the binding of $^3H$-$E_2$ to ER sufficiently(binding efficiency of 54.8%). ER was saturated with 4nM of $^3H$-$E_2$ and its dissociation constant was 0.1nM. ER assay using frozen sections(Histological radioreceptor assay, HRRA) was significantly correlated with radioreceptor assay for estradiol(RRA, 0.976 , p

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.649-652
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• 2011

A series of hybrid rocket combustion experiments were carried out with PMMA/GOx changing diameter and length of the disk installed at pre-chamber. The disk can generate vortex shedding flow and change flow conditions prior to entering the fuel grain which could also alter the combustion characteristics and pressure oscillations. Isolated dimple-like surface roughness patterns distributed all over the fuel surface, which can be thought of as a realization of the inherent flow instability. It is very likely that the formation of cell structures is originated from the modification of boundary layer characteristics of an entering oxidizer flow caused by a blowing effect mainly taking place near the wall. This coincided with our LES results. It would be a meaningful basis to understand combustion instability of hybrid rocket motor.

• The Journal of Korean Medicine
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• v.41 no.2
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• pp.107-121
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• 2020

Objectives: The purpose of this study was to identify the characteristics of patients who visited the emergency room (ER) of a Korean medicine (KM) hospital and to provide basic data for further research. Methods: We conducted a retrospective analysis using electronic medical records of 263 patients who visited the ER of OO University Oriental Hospital from January 1 to December 31, 2019. Results: Of the 263 patients' medical records, 245 were included in this analysis. The male-to-female ratio was 1.09:1. The average age was 52 years, with patients in their 40s having the largest distribution. The district where the hospital was located had the largest number of patients. The distribution by visit time was the lowest in the early morning. Most patients visited on Sunday, in September, and on the day of onset. The admission rate was 39.18%, and largest number of patients was admitted to the Department of Acupuncture and Moxibustion. The percentage of patients who revisited the KM hospital as an outpatient were 26.17%. The diagnosis for most patients was musculoskeletal disease. Acupuncture was the most common treatment, accounting for 62.45% of the cases, followed by herbal medicines, accounting for 54.69% of the cases. National health insurance was the most common type of insurance registered. Most patients visited the ER of the KM hospital via the ER of the hospital. Conclusions: This clinical analysis helped us identify the characteristics of patients visiting the ER of a KM hospital. Continuous data accumulation is required in relation to this for further studies.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2107-2113
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• 2000

Toxicity estimation of three nonionic surfactants (Brij 30, Tween 80, Triton X-lOO) and their effect on the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in the aqueous phase and soil slurry phase were investigated. Brij 30 was found to be the most biodegradable among the surfactants tested, and showed no substrate inhibition up to a concentration of 1.5 g/L. It was definitely utilized as a carbon source by the microorganisms. Naphthalene and phenanthrene in the aqueous phase were completely degraded by phenanthrene-acclimated cultures within 60 hours, but a substantial amount of naphthalene was lost due to the volatilization. The limiting step in the soil slurry bioremediation was bioavailablity by the microorganisms in the sand slurry and mass transfer from a solid to aqueous phase in the clay slurry. TOC analysis revealed that most of substrates including surfactant in the reactor were degraded. pH transition indicated that phenanthrene was metabolized into intermediates containing acid function.

• The KIPS Transactions:PartD
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• v.11D no.7 s.96
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• pp.1367-1374
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• 2004

For sharing XML data by many users, a way of concurrency and access control is required for isolating update actions such as inserting and deleting subtrees. Exisiting locking mechanisms as 2PL or MGL suffer low concurrency when applied to tree structures. In this paper, list data subtrees model is proposed based on the semantics expressed in DTD. In this model, tree updating actions such as inserting and deleting subtrees are considered only for the repetitive parts of XML trees. The proposed model guarantees that the result XML tree after applying a tree updating action is always valid, even when multiple users access the tree at the same time. Also, a new locking mechanism called list lock-ing protocol is proposed. The new locking protocol is expected to show better accessility with less number of locking objects compared to the Helmer's OO2PL model. Since update actions on a shared XML tree usually applied to the repetitive parts of the tree, the proposed model is expected to provide a useful way for efficient data sharing when combined with previous locking methods on terminal node data.

• Journal of The Korean Society of Clinical Toxicology
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• v.9 no.2
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• pp.77-80
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• 2011

Purpose: The purpose of this study was to investigate the relationship between patients with a neuropsychiatric history and features of their suicide attempt, in order to analyze the risk associated with psychiatrist prescribed drugs Methods: We retrospectively investigated cases of intentional overdose drug ingestion in patients greater than 14 years of age who visited OO emergency medical center between January 1, 2008 and July 31, 2010. We evaluated patient medical records to ascertain their age, sex, neuropsychiatric history, and components of ingested intoxicant. Information regarding any suicide reattempt was obtained after discharge through follow up telephone survey. SPSS version 13.0 was used for statistical analysis. Fisher's exact test was performed with p<0.05 considered statistically significant. Results: Ninety-six of 209 patients (46%) had a past history of psychological problems. Among those 96 patients with a history of psychological problems, 46(48%) used an overdose of the medicine prescribed by their psychologist in order to attempt suicide. However, for patients without a history of psychological problems, intoxication by neuropsychiatric drugs was insignificant. Neuropsychiatric patients required greater follow up care after discharge and exhibited significantly more suicide reattempts. Conclusion: This study revealed that patients sometimes use the medicine prescribed by their psychologist to attempt suicide. Therefore, an exhaustive plan to control the medicines prescribed to psychiatric patients should be established.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.139-144
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• 2005

A rigorous research is underway in our team, for the design and development of high figure of merits (ZT= 1.5${\sim}$2.0) micro-thermoelectric coolers. This paper discusses the fabrication process that we are using for developing the $Sb_2Te_3-Bi_2Te_3$ micro-thermoelectric cooling modules. It describes how to obtain the mechanical properties of the thin film TEC elements and reports the results of an equation-based multiphysics modeling of the micro-TEC modules. In this study the thermoelectric thin films were deposited on Si substrates using co-sputtering method. The physical mechanical properties of the prepared films were measured by nanoindentation testing method while the thermal and electrical properties required for modeling were obtained from existing literature. A finite element model was developed using an equation-based multiphysics modeling by the commercial finite element code FEMLAB. The model was solved for different operating conditions. The temperature and the stress distributions in the P and N elements of the TEC as well as in the metal connector were obtained. The temperature distributions of the system obtained from simulation results showed good agreement with the analytical results existing in literature. In addition, it was found that the maximum stress in the system occurs at the bonding part of the TEC i.e. between the metal connectors and TE elements of the module.

• Journal of The Korean Association of Information Education
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• v.24 no.3
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• pp.233-241
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• 2020

This study has developed and applied an elementary EPL education program centered on execution time as an educational method for improving Computational thinking of elementary school students, and then its effect has been verified. The education program was developed based on the results of preliminary demand analysis conducted on 48 elementary school students. In order to verify the effectiveness of the education program, 25 students were asked to participate in the class of elementary school students on a seven hours for six days. Using the "Korea Bebras Challenge 2018", educational effects were analyzed through the results of pre- and post-mortem examinations, and the analysis showed that elementary EPL education centered on performance time was effective in improving computational thinking of elementary school students