• Steel and Composite Structures
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• v.52 no.3
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• pp.343-356
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• 2024

This paper presents an analytical solution for correctly predicting the Lateral-Torsional Buckling critical moment of simply supported castellated beams, the solution covers uniformly distributed loads combined with compressive loads. For this purpose, the castellated beam section with hexagonal-type perforation is treated as an arrangement of double "T" sections, composed of an upper T section and a lower T section. The castellated beam with regular openings is considered as a periodic repeating structure of unit cells. According to the kinematic model, the energy principle is applied in the context of geometric nonlinearity and the linear elastic behavior of materials. The differential equilibrium equations are established using Galerkin's method and the tangential stiffness matrix is calculated to determine the critical lateral torsional buckling loads. A Finite Element simulation using ABAQUS software is performed to verify the accuracy of the suggested analytical solution, each castellated beam is modelled with appropriate sizes meshes by thin shell elements S8R, the chosen element has 8 nodes and six degrees of freedom per node, including five integration points through the thickness, the Lanczos eigen-solver of ABAQUS was used to conduct elastic buckling analysis. It has been demonstrated that the proposed analytical solution results are in good agreement with those of the finite element method. A parametric study involving geometric and mechanical parameters is carried out, the intensity of the compressive load is also included. In comparison with the linear solution, it has been found that the linear stability underestimates the lateral buckling resistance. It has been confirmed that when high axial loads are applied, an impressive reduction in critical loads has been observed. It can be concluded that the obtained analytical solution is efficient and simple, and offers a rapid and direct method for estimating the lateral torsional buckling critical moment of simply supported castellated beams.

• Archives of Plastic Surgery
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• v.34 no.6
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• pp.724-728
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• 2007

Purpose: The objective of this study is to prevent postoperative lower eyelid retraction and scleral show. There are several approaches for orbital rim reconstruction. But these techniques are sometimes difficult to perform, and have some merits and faults. Maybe most common unwanted and unpleasant result that we have experienced by subciliary incision preseptal approach is the lower eyelid retraction and the scleral show. Therefore, I want to find out the causes and the solutions for such complication. We must know the mechanics for those unpleasant result first of all. Methods: We conducted a comparison of postoperative photographs between retroseptal approach group and preseptal approach group, both with subciliary incision. In experimental retroseptal group, incision was applied at subciliary region. After elevating skin flap to preserve pretarsal muscle, not with muscle flap elevation, but direct oblique incision through the muscle, retroseptal dissection was applied to the ROOF and the septum. Fixating fracture line, periosteal and septal repair was followed by skin repair. The light compressive dressings and protection were kept in place for 7 days. The effectiveness of this operative method was made comparison with control group which the preseptal approach was applied to, by postoperative 2nd week and 2nd month. Results: Author's technique had been used in 20 patients and control group was composed of 50 patients over 19months period. There were better results in experimental group than in control group and all of experimental group had no complaint about the lower eyelid retraction and the scleral show. Conclusion: It must be known about the reason of the lower eyelid retraction and the scleral show induced by subciliary and preseptal approach. Mechanically it can be easily proved. And the solution maybe will be easier if we get more information about the mechanics. I recommend the retroseptal subciliary approach

• Steel and Composite Structures
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• v.26 no.4
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• pp.485-499
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• 2018

In this paper, a hollow steel tube (HST) shear connector is proposed for use in a slim-floor system. The HST welded to a perforated steel beam web and embedded in concrete slab. A total of 10 push-out tests were conducted under static loading to investigate the mechanical behavior of the proposed HST connector. The variables were the shapes (circular, square and rectangular) and sizes of hollow steel tubes, and the compressive strength of the concrete. The failure mode was recorded as: concrete slab compressive failure under the steel tube and concrete tensile splitting failure, where no failure occurred in the HST. Test results show that the square shape HST in filled via concrete strength 40 MPa carried the highest shear load value, showing three times more than the reference specimens. It also recorded less slip behavior, and less compressive failure mode in concrete underneath the square hollow connector in comparison with the circular and rectangular HST connectors in both concrete strengths. The rectangular HST shows a 20% higher shear resistance with a longer width in the load direction in comparison with that in the smaller dimension. The energy absorption capacity values showed 23% and 18% improvements with the square HST rather than a headed shear stud when embedded in concrete strengths of 25 MPa and 40 MPa, respectively. Moreover, an analytical method was proposed and predicts the shear resistance of the HST shear connectors with a standard deviation of 0.14 considering the shape and size of the connectors.

• Korean Journal of Adult Nursing
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• v.17 no.4
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• pp.668-678
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• 2005

Purpose: The purpose of this study was to provide the basic data of a comprehensive counter-plan to promote health for people by comparing various factors related to cancer outbreak factors including general characteristics, health-related lifestyles, health promoting behaviors, perceived healthy status, life event stress and health care seeking behaviors with cancer patients and health people. Method: The study was designed to be a retrospective-comparison-survey-study and its data was collected through 5 types of questionnaires from September 2003 to December 2003. Results: Cancer patients had lower education and household income, and many of them had no occupation. Cancer patients had a higher rate of smoking and drinking periods. Exercise level was higher in healthy people. However, Cancer patients were better in sleep and rest. In comparison with health promoting behaviors, it was higher in healthy people than in cancer patients but the two groups had no significant differences statistically. The perceived health status was higher in healthy people than in cancer patients. The health care seeking behaviors were higher in healthy people than in cancer patients. Cancer patients and healthy people's life event stress had no significant differences statistically. Conclusion: As a result of comparative analysis of cancer patients and healthy people's health risk factors, smoking, drinking period, regular exercise and health care seeking behaviors were suggested as direct or indirect risk factors for cancer patients. These finding can be applied to health promoting behavior programs to keep and promote optimal health status as well as to prevent cancer disease.

• Journal of The Korean Astronomical Society
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• v.36 no.2
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• pp.55-60
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• 2003

In Lee, Kang & Byun (2001) the discovery of Raman scattered 6545 A feature was reported in symbiotic stars and the planetary nebula M2-9. The broad emission feature around 6545 A is formed as a result of Raman scattering of He II n = 6 $\to$ n = 2 photons by atomic hydrogen. In this paper, we introduce a method to compute the equivalent width of He II $\lambda$ 1025 line and present an optical spectrum of the symbiotic star RR Telescopii as an example for a detailed illustration. In this spectrum, we pay attention to the broad H$\alpha$ wings and the Raman scattered He II 6545 feature. The broad Ha wings are also proposed to be formed through Raman scattering of continuum around Ly$\beta$ by Lee (2000), and therefore we propose that the equivalent width of the He II $\lambda$ 1025 emission line is obtained by a simple comparison of the strengths of the 6545 feature and the broad H$\alpha$ wings. We prepare a template H$\alpha$ wing profile from continuum radiation around Ly$\beta$ with the neutral scattering region that is supposed to be responsible for the formation of Raman scattered He II 6545 feature. Isolation of the 6545 feature that is blended with [N II] $\lambda$ 6548 is made by using the fact that [N II] $\lambda$ 6584 is always 3 times stronger than [N II] $\lambda$ 6548. We also fit the 6545 feature by a Gaussian which has a width 6.4 times that of the He II $\lambda$ 6527 line. A direct comparison of these two features for RR Tel yields the equivalent width $EW_{Hel025} = 2.3{\AA}$ of He II $\lambda$ 1025 line. Even though this far UV emission line is not directly observable due to heavy interstellar extinction, nearby He II lines such as He II $\lambda$ 1085 line may be observed using far UV space instruments, which will verify this calculation and hence the origins of various features occurring in spectra around H$\alpha$.

• Korean Journal of Materials Research
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• v.24 no.2
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• pp.87-92
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• 2014

The Notched Ring Test(NRT) has proven to be very useful in determining the slow crack growth behavior of polyethylene pressure pipes. In particular, the test is simple and an order of magnitude shorter in experimental times as compared to the currently used Notched Pipe Test(NPT), which makes this method attractive for use as the accelerated slow crack growth test. In addition, since the NRT specimen is taken directly from the pipe, having maintained the cross-section, processing induced artifacts that would affect the slow crack growth behavior are not altered. This makes the direct comparison to the slow crack growth specimen in pipe from more meaningful. In this study, for comparison with other available slow crack growth methods, including the NPT, the stress intensity factor equation for NRT specimen was developed and demonstrated of its accuracy within 3% of that obtained from the finite element analysis. The equation was derived using a flexure formula of curved beam bending along with numerically determined geometric factors. The accuracy of the equation was successfully tested on 63, 110, 140, 160, 250, and 400 mm nominal pipe diameters, with crack depth ranging from 15 % to 45 % of the pipe wall thickness, and for standard dimensional ratio(SDR) of 9, 11, and 13.6. Using this equation the slow crack results from 110SDR11 NRT specimen were compared to that from the NPT specimen, which demonstrated that the NRT specimen was equivalent to the NPT specimen in creating the slow crack, however in much shorter experimental times.

• Journal of the Korean housing association
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• v.18 no.6
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• pp.25-34
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• 2007

The purpose of this qualitative research is to compare the community service and situation of SH apartment in Yangcheon-Gu and PHA apartment in Minnesota in order to grasp the requirement for livable community. For the study, depth-interview method was used to collect the data. Throughout this research, we found the ways to create a livable community as follows: Rental apartments are supplied by Seoul Housing agency in Korea while in US by PHA, an independent government agency. Both of them are in direct management. There are five main topics to be discussed. First, as a main supplier of services, it is Yangchun-Gu's social welfare center in Korea, while PHA in US. Second, as a mean of giving services, Korean residents visit the welfare center. On the other hand, PHA apartments enforces service-to-customer policies. Third, as a Korean service, they are consultation targeting families, children, teenagers, disabled, olds, education, medical examinations, rehabilitation and free meals. In US PHA apartments, they are medical health professionals, social worker, beauty salon or barber shop, bus to shopping area, bookmobile, OK card program, CHSP, ASI, ALP, personal care, senior/congregate dinning and etc. Fourth, both Korean and US have same hindrance for the 'livable community' policies which is funding and conflict of residents. Fifth, both Korean and US think that the key for the success of 'livable community' are resources, service and residents. The differences between Korea and US concerning service conditions such as supply of rental apartments, management and services are caused by cultural, ethnic and economical differences. From another point of view, Korean apartments are predicted to have similar problems like PHA apartments, and preparative attitude for this is needed.

• Journal of Environmental Health Sciences
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• v.39 no.1
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• pp.71-82
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• 2013

Objectives: This study was performed in order to investigate hand hygiene practices among food-service businesses employees based on the awareness of hand-washing and load of indicator bacteria on their hands. It focused on the comparison of full-time and part-time workers in food-service workplaces. Methods: A direct-interview questionnaire survey and microbiological analysis were carried out with sixty workers each. Samples for microbiological analysis were collected through a modified glove-juice method from the hands of the food-service workers and were analyzed for aerobic plate count, total coliform, fecal coliform, Escherichia coli, Staphylococcus aureus, and Salmonella spp. Microbiological analysis was done according to the Food Code of Korea. Results: Significant differences (p<0.01) were found in the survey between the full-time and part-time workers in hand-washing frequency, use of hand-washing agents, and hand-drying methods. More full-time workers responded to washing their hands after preparing food, after visiting outside, after handling raw materials, and before putting on gloves/when changing gloves than did part-time workers (p<0.05). No remarkable difference was found in bacterial load on the hands except in the aerobic plate count between the two groups. The detection of E. coli, S. aureus, and Salmonella spp. on the hands of some food-service workers in both groups revealed poor hand hygiene practices. Conclusions: The results of this study indicate that there is a need for training programs in order to improve hand hygiene practices and strict hand hygiene compliance by food-service workers.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.2
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• pp.105-113
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• 2022

Purpose: The purpose of this study is to investigate the effect of non-invasive transcranial direct current stimulation (tDCS) on muscle activity, including 10 m WT, TUG, and BBS, in hemiplegic stroke patients. Methods: This study was conducted on 42 inpatients diagnosed with hemiplegia due to stroke at hospital B in Daejeon for more than 6 months. Walking training was conducted for six weeks, five times a week for 30 minutes, with a general walking group (14 people), tDCS walking group (14 people), and tDCS (sham) walking group (14 people). Results: As a result of the study, the change in the muscle activity before and after tDCS intervention was significantly increased in the tibialis anterior muscle in the CG group. In the EG group, the erector spine (lumbar), rectus femoris, and tibialis anterior muscles significantly increased. In the SEG group, significant increases were observed in the rectus femoris and tibialis anterior muscles. Significant differences were found in the rectus femoris and tibialis anterior muscles in the comparison between groups after intervention according to tDCS application. Also, 10 m WT, TUG, and BBS were significantly increased in the CG, EG, and SEG groups after intervention, and there were significant differences in 10 m WT, TUG, and BBS in comparison between groups after intervention according to tDCS application. Conclusion: As a result, tDCS is an effective in improving the walking ability of stroke patients, and in particular, it effectively increases the muscle activity of the rectus femoris and tibialis anterior muscles, which act directly on walking, and also improves the speed and stability of walking. It is considered being an effective method to increase the gait of stroke patients by combining it with the existing gait training.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.337-343
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• 2014

Purpose : The aim of this study is to evaluate unwanted scattered dose to ovary by scattering and leakage generated from treatment fields of Tomotherapy for childbearing woman with breast cancer. Materials and Methods : The radiation treatments plans for left breast cancer were established using Tomotherapy planning system (Tomotherapy, Inc, USA). They were generated by using helical and direct Tomotherapy methods for comparison. The CT images for the planning were scanned with 2.5 mm slice thickness using anthropomorphic phantom (Alderson-Rando phantom, The Phantom Laboratory, USA). The measurement points for the ovary dose were determined at the points laterally 30 cm apart from mid-point of treatment field of the pelvis. The measurements were repeated five times and averaged using glass dosimeters (1.5 mm diameter and 12 mm of length) equipped with low-energy correction filter. The measures dose values were also converted to Organ Equivalent Dose (OED) by the linear exponential dose-response model. Results : Scattered doses of ovary which were measured based on two methods of Tomo helical and Tomo direct showed average of $64.94{\pm}0.84mGy$ and $37.64{\pm}1.20mGy$ in left ovary part and average of $64.38{\pm}1.85mGy$ and $32.96{\pm}1.11mGy$ in right ovary part. This showed when executing Tomotherapy, measured scattered dose of Tomo Helical method which has relatively greater monitor units (MUs) and longer irradiation time are approximately 1.8 times higher than Tomo direct method. Conclusion : Scattered dose of left and right ovary of childbearing women is lower than ICRP recommended does which is not seriously worried level against the infertility and secondary cancer occurrence. However, as breast cancer occurrence ages become younger in the future and radiation therapy using high-precision image guidance equipment like Tomotherapy is developed, clinical follow-up studies about the ovary dose of childbearing women patients would be more required.