• Journal of Adhesion and Interface
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• v.12 no.3
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• pp.81-87
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• 2011

In this study, UV curing and crosslinking process was introduced for synthesis of acrylic foam tape that can be applied to the the automotive assembly process. Polymerized adhesive are laminated to baseform and varying the thickness of specimens were prepared. To measure basic mechanical properties, stainless steel was used. And in the test peel, dynamic shear and t-block were used. The acrylform adhesive show better results compare with typical adhesive and the properties depand on external factors - thick, wetting time -. To analysis functions of acrylic foam adhesive used to automobile production, evaluate the adhesive properties on the various plastic substrate. In PP and PE are categorized low surface energy materials, their properties have not been expressed. But dynamic shear tests show that some properties could be expressed by the difference break mechanism.

• Journal of Platform Technology
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• v.9 no.3
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• pp.3-17
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• 2021

Advanced persistent threat (APT) attacks are attacks aimed at a particular entity as a set of latent and persistent computer hacking processes. These APT attacks are usually carried out through various methods, including spam mail and disguised banner advertising. The same name is also used for files, since most of them are distributed via spam mail disguised as invoices, shipment documents, and purchase orders. In addition, such Infostealer attacks were the most frequently discovered malicious code in the first week of February 2021. CDR is a 'Content Disarm & Reconstruction' technology that can prevent the risk of malware infection by removing potential security threats from files and recombining them into safe files. Gartner, a global IT advisory organization, recommends CDR as a solution to attacks in the form of attachments. There is a program using CDR techniques released as open source is called 'Dangerzone'. The program supports the extension of most document files, but does not support the extension of HWP files that are widely used in Korea. In addition, Gmail blocks malicious URLs first, but it does not block malicious URLs in mail systems such as Naver and Daum, so malicious URLs can be easily distributed. Based on this problem, we developed a 'Dangerzone' program that supports the HWP extension to prevent APT attacks, and a Chrome extension that performs URL checking in Naver and Daum mail and blocking banner ads.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.1-16
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• 2022

The location of the bus stop on urban roads should be installed at a point where it is convenient for users and the impact of bus stops on the traffic flow is minimized. However, the location of the bus stops is determined indiscriminately due to the lack of related research. Therefore, this study developed a traffic accident prediction model and calculated the proper separation distance for the bus stops through an optimization technique. The result of the study indicates that the bus stop can be installed in the form of a mid-block approximately 87 to 166 m away from the intersection in the road section. This result is valid if the number of main road lanes in the road section is 2 to 4 with a level of traffic from 1,000 to 3,000 v/h. In the section with 5 to 6 lanes, it is desirable to install a bus stop close to the intersection by about 42 to 97 m.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.3
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• pp.38-46
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• 2023

In this study, a bearing test was performed and analytically evaluated to evaluate the bearing performance according to the application of the aluminum stiffener in round-end concrete. In the bearing strength test, the change in bearing performance due to the aluminum stiffener using the aluminum form for manufacturing concrete with round-end, and the steel anchor bolts for member movement and assembly was confirmed. The FE analysis model was identically configured to the experimental conditions, and the result was compared with the experiment. Also, the crack patterns and stress behavior were confirmed. In addition, the effect of strength change of the aluminum stiffener on the round-end concrete was also evaluated analytically. The bearing strength of the round-end concrete increased by about 20% due to the aluminum stiffener, and it was confirmed that the steel anchor bolt did not affect the bearing strength. The maximum load and crack patterns shown as a result of FE analysis were similar to those of the experiment. As a result of FE analysis according to the strength change of the aluminum stiffener, the maximum load change according to the increase and decrease of the strength of the aluminum stiffener by 10% and 20% was evaluated to have no significant effect at a maximum of about 4% compared to before the strength change.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.3
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• pp.121-128
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• 2015

Background: The authors studied the hemodynamic effect influent by using the novel high concentration of lidocaine HCl for surgical removal impacted lower third molar. The objective of this study was to evaluate the hemodynamic change when using different concentrations of lidocaine in impacted lower third molar surgery. Methods: Split mouth single blind study comprising 31 healthy patients with a mean age of 23 years (range 19-33 years). Subjects had symmetrically impacted lower third molars as observed on panoramic radiograph. Each participant required 2 surgical interventions by the same surgeon with a 3-week washout period washout period. The participants were alternately assigned one of two types of local anesthetic (left or right) for the first surgery, then the other type of anesthetic for the second surgery. One solution was 4% lidocaine with 1:100,000 epinephrine and the other was 2% lidocaine with 1:100,000 epinephrine. A standard IANB with 1.8 ml volume was used. Any requirement for additional anesthetic and patient pain intra-operation was recorded. Post-operatively, patient was instructed to fill in the patient report form for any adverse effect and local anesthetic preference in terms of intra-operative pain. This form was collected at the seven day follow up appointment. Results: In the 4% lidocaine group, the heart rate increased during the first minute post-injection (P < 0.05). However, there was no significant change in arterial blood pressure during the operation. In the 2% lidocaine group, there was a significant increase in arterial blood pressure and heart rate in the first minute following injection for every procedure. When the hemodynamic changes in each group were compared, the 4% lidocaine group had significantly lower arterial blood pressure compared to the 2% lidocaine group following injection. Post-operatively, no adverse effects were observed by the operator and patient in either local anesthetic group. Patients reported less pain intra-operation in the 4% lidocaine group compared with the 2% lidocaine group (P < .05). Conclusions: Our results suggest that a 4% concentration of lidocaine HCl with 1:100,000 epinephrine has better clinical efficacy than 2% lidocaine HCl with 1:100,000 epinephrine when used for surgical extraction of lower third molars. Neither drug had any clinical adverse effects.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1B
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• pp.59-69
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• 2012

Probabilistic design is required to effectively consider the coastal environment of great uncertainty. However, designers who are familiar with the deterministic design method prefer a method which is similar to the existing method but is based on the probabilistic concept. Therefore, the partial safety factor method has been adopted as a new design method over the world. In Korea, Tetrapod is widely used for armoring rubble mound breakwaters. Even though the partial safety factor method developed in the United States and Europe covers Tetrapods, the limited wave and structure conditions in its development make the engineers hesitate about its use in practical breakwater design. In this study, partial safety factors for Tetrapod armor blocks have been developed by analyzing 116 breakwater cross-sections and wave conditions in 16 trade harbors and 15 coastal harbors with the FORM and optimal code calibration approach. Especially, partial safety factors have been proposed depending on the shape parameter of the Weibull extreme wave height distribution. For other types of extreme distributions, it is possible to apply the proposed partial safety factors using the relationship between skewness coefficient and shape parameter. Finally, the proposed partial safety factors have been applied to existing structures to show that they better satisfy the target reliability of the structures than previous partial safety factors.

• Korean Journal of Biological Psychiatry
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• v.2 no.1
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• pp.57-62
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• 1995

Objects : Clozapine, prototype of the atypical neuroleptics, was known to have unique antipsychotic effect with a few extrapyramidal effects. While most typical antipsychotic agents mainly block $D_2$ receptors, clozapine has higher affinity for dopamine $D_4$ receptor than for $D_2$ receptor. Many researchers have tried to find out the relationship between schizophrenia and the abnormality of the genes coding dopamine receptors. But no consistent findings were reported. Recently, dopamine $D_4$ receptor was fully sequenced, and the alleles of dopamine $D_4$ receptor gene was found in unusual form on the 48th base pair. Our study was performed to identify the distribution of the dopamine $D_4$ receptor alleles of schizophrenics and normal controls, and whether any difference between the dopamine $D_4$ receptor alleles of schizophrenics and that of normal controls exists. Methods : DNA was extracted from the blood of schizophrenic patients(N=60) and normal controls(N=60). Part of the dopamine $D_4$ receptor gene was amplified by PCR, and amplified DNA was electrophoresed. Authors compared the distribution of the alleles of dopamine $D_4$ receptor gene of normal controls and that of schizophrenic patients. Results : Six kinds of alleles of $D_4$ receptor were observed both groups. The fourth repeat form of alleles was the most common in both schizophrenic patients(75.8%) and normal controls(70.3%), so there was not significant difference between two groups. Conclusion : The Difference in the distribution of the dopamine $D_4$ receptor gene alleles is not thought to be responsible for the pathophysiology of the schizophrenia. However, the difference in the expression of the dopamine $D_4$ receptor gene between normal and schizophrenia is left to be scrutinized.

• Journal of the Korean Chemical Society
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• v.18 no.5
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• pp.329-340
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• 1974

Sulfadiazine, $C_{10}H_{10}N_4O_2S$, forms monoclinic crystals of space group $P21}c$ from a mixture of acetone and ethanol with $a=13.71{\pm}0.04,\;b=5.84{\pm}0.03,\;c=15.11{\pm}0.05{\AA},\;{\beta}=115.0{\pm}0.3^{\circ}$, and four molecules per cell. Three dimensional photographic data were collected with $CuK\alpha$ radiation. The structure was determined using Patterson and Fourier synthesis methods and refined by block diagonal least-squares methods with isotropic thermal parameter for all non-hydrogen atoms. The final R value was 0.15 for the 1517 observed independent reflections. The dihedral angle between the planes through the benzene ring and the pyrimidine ring is $76^{\circ}$. The conformational angle formed by the projection of the S-C(5) bond with that of N(1)-C(1) where the projection is taken along the S-N(1) bond is $77^{\circ}$. The imino nitrogen atom, N(1), and pyrimidine nitrogen atom, N(3), form intermolecular $N-H{\cdots}N$ hydrogen bond between the molecules related by center of symmetry. Amino nitrogen atom, N(4), forms two intermolecular $N-H{\cdots}O$ hydrogen bonds, with O(1) and O(2) atoms of different molecules separated by b. A two dimensional network of hydrogen bonds form infinite molecular sheets parallel to the (100) plane. Adjacent sheets are bound together by van der Waals forces.

• Economic and Environmental Geology
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• v.31 no.3
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• pp.235-247
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• 1998

A new technique of simultaneons inversion for 3-D seismic velocity structure by using direct, reflected, and refracted waves is applied to the center of the Korean Peninsula including Pyongnam Basin, Kyonggi Massif, Okchon Fold Zone, Taebaeksan Fold Zone, Ryongnam Massif and Kyongsang Basin. Pg, Sg, PmP, SmS, Pn, and Sn arrival times of 32 events with 404 seismic rays are inverted for locations and crustal structure. 5 ($1^{\circ}$ along the latitude)${\times}6$ ($0.5^{\circ}$ along the longitude) ${\times}8$ block (4 km each layer) model was inverted. 3-D seismic crustal velocity tomography including eight sections from the surface to the Moho, eight profiles along latitude and longitude and the Moho depth distribution was determined. The results are as follows: (1) the average velocity and thickness of sediment are 5.15 km/sec and 3-4 km, and the velocity of basement is 6.12 km/sec. (2) the velocities fluctuate strongly in the upper crust, and the velocity distribution of the lower crust under Conrad appears basically horizontal. (3) the average depth of Moho is 29.8 km and velocity is 7.97 km/sec. (4) from the sedimentary depth and velocity, basement thickness and velocity, form of the upper crust, the Moho depth and form of the remarkable crustal velocity differences among Pyongnam Basin, Kyonggi Massif, Okchon Zone, Ryongnam Massif and Kyongsang Basin can be found. (5) The different crustal features of ocean and continent crust are obvious. (6) Some deep index of the Chugaryong Rift Zone can be located from the cross section profiles. (7) We note that there are big anisotropy bodies near north of Seoul and Hongsung in the upper crust, implying that they may be related to the Chugaryong Rift Zone and deep fault systems.

• Journal of Internet of Things and Convergence
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• v.8 no.6
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• pp.93-97
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• 2022

The purpose of this study is to suggest implications for early childhood SW·AI education considering the characteristics of early childhood education through a survey on SW·AI education in kindergartens. For this study, data were collected from 194 kindergartens through convenience sampling. The data was analyzed using frequency distribution, and it was found that 44% of kindergartens are conducting SW·AI education. 22% are conducting SW·AI education in the form of regular curriculum, and 70% are conducting SW·AI education in the form of special activities after school. SW·AI education was found to be conducted mainly by external instructors (97%) in the classroom (80%). For SW·AI education, block coding-based programs developed by companies such as Naver and the Clova were used, and all of these programs used programs and teaching aids in a package format, including teaching aids and materials developed by companies. 56% answered that they are not currently conducting SW/AI education, and lack of awareness on SW·AI education and lack of human/environmental infrastructure were the main factors. In order to realize SW·AI education considering the characteristics of early childhood education based on this survey, First, SW·AI education programs should be developed to develop play-centered computational thinking skills. Second, systematic teacher education at the national level should be conducted. Finally, the establishment of a department dedicated to early childhood SW·AI consisting of early childhood education experts and SW·AI education experts and financial support at the national level should be provided.