• Advances in nano research
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• v.15 no.6
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• pp.495-511
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• 2023

In this research, the impact of micro-silica, nano-silica, and polypropylene fibers on the fracture energy of self-compacting concrete was thoroughly examined. Enhancing the fracture energy is very important to increase the crack propagation resistance. The study focused on evaluating the self-compacting properties of the concrete through various tests, including J-ring, V-funnel, slump flow, and T50 tests. Additionally, the mechanical properties of the concrete, such as compressive and tensile strengths, modulus of elasticity, and fracture parameters were investigated on hardened specimens after 28 days. The results demonstrated that the incorporation of micro-silica and nano-silica not only decreased the rheological aspects of self-compacting concrete but also significantly enhanced its mechanical properties, particularly the compressive strength. On the other hand, the inclusion of polypropylene fibers had a positive impact on fracture parameters, tensile strength, and flexural strength of the specimens. Utilizing the response surface method, the relationship between micro-silica, nano-silica, and fibers was established. The optimal combination for achieving the highest compressive strength was found to be 5% micro-silica, 0.75% nano-silica, and 0.1% fibers. Furthermore, for obtaining the best mixture with superior tensile strength, flexural strength, modulus of elasticity, and fracture energy, the ideal proportion was determined as 5% micro-silica, 0.75% nano-silica, and 0.15% fibers. Compared to the control mixture, the aforementioned parameters showed significant improvements of 26.3%, 30.3%, 34.3%, and 34.3%, respectively. In order to accurately model the tensile cracking of concrete, the authors used softening curves derived from an inverse algorithm proposed by them. This method allowed for a precise and detailed analysis of the concrete under tensile stress. This study explores the effects of micro-silica, nano-silica, and polypropylene fibers on self-compacting concrete and shows their influences on the fracture energy and various mechanical properties of the concrete. The results offer valuable insights for optimizing the concrete mix to achieve desired strength and performance characteristics.

• Journal of Pharmacopuncture
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• v.26 no.4
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• pp.285-297
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• 2023

Objectives: The aim of this systematic review and meta-analysis is to assess and compare the effectiveness of manual therapy in alleviating infant crying, a common symptom of nocturnal crying (NC) and infantile colic (IC). Methods: Total effective rate, crying time and adverse events were used as outcome indicators. To assess the quality, the risk of bias was determined for each study by two authors, using the Cochrane Collaboration's risk of bias tool. RevMan 5.0 was used for data analysis. A total of 98 articles were identified from 6 electronic databases. Results: Among them, twenty-seven studies which included 13 NC and 14 IC were included. Meta-analysis showed favorable effects tuina therapy on total effective rate (TER) of NC (RR: 1.20 [95% CI 1.05 to 1.37], p = 0.007), chiropractic therapy on crying time change of IC (SMD: -0.83 [95% CI -1.61 to -0.06], p = 0.04) and massage on total crying time of IC (SMD: -0.86 [95% CI -1.09 to -0.63], p < 0.00001). This systematic review compares different manual therapies for the treatment of NC and IC. While tuina, chiropractic, and massage show results in alleviating symptoms, the overall evidence remains limited due to the low quality and heterogeneity of the included studies. Conclusion: Therefore, further high-quality research with unified control groups is needed to establish manual therapy as a recommended treatment option for NC and IC. Protocol registration number is CRD42022348143 01/08/2022.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.168-175
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• 2011

Construction accidents are major problem in Turkish Construction industry and especially fatally rates are very high. Current legislative system on occupational safety in Turkey enforces employers to implement safety measures as well as safety management systems. However level of consciousness in the industry is unsatisfactory and safety are perceived as extra cost and unnecessary expenditure. Moreover, especially in small residential building constructions which have a big share in the industry and unfortunately safety measures to mitigate or abate construction risks do not exist. The study focuses on small residential building construction sites and in the scope of this study, thirty building projects are examined. For each building project, project cost including labour and material costs, service and consultancy costs for mechanical, electrical systems as well as architectural and structural services, costs for supervision and finally general expenditures for construction site facilities were calculated. On the other hand, occupational safety costs for personal protective equipment, collective protective measures, consultancy and training were determined. Work breakdown structures were established and for each work item firstly occupational risks were evaluated and furthermore according to risk scores safety measures to be implemented were defined and related costs were calculated. The study gave results for total safety cost on average, in terms of percentage of total project cost (3.73% of total project cost), safety cost per man-hour (0.40 USD) and safety cost in terms of unit construction area (11.60 USD per square meter). Since safety management is a part of whole project management process, study gives suggestions and techniques to calculate safety costs and implement safety measures as a part of project management service for professionals. Authors believe that suggested approach may easily developed by the usage of more data to establish a model for estimation not only for building construction sites but also for all construction projects.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.94-100
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• 1985

M/S Pusan 403(GT 243, 1000ps) was originally built as a research vessel on skipjack pole and line fishing in 1972. She had begun to serve as a fishing training ship of National Fisheries University of Pusan from 1974, since the interior structure has been remodelled and some weight articles have been removed, her stability is in doubt. The authors carried out an inclining experiment by using two pendulums at fore and aft with two weights on both sides. Each value obtained was compared with the IMO safety code for fishing vessels and safety regulation for fishing vessels of Korea. 1. The GZ value, being 0.207 m under light ship condition and 0.325 m under departure condition with full load, can be assumed as no impediment on her stability, 2. Under the light ship condition, GM decreased by 0.046 m and KG increased by 0.141 m, compared with the values determined at the time of official sea trial. Therefore, no impediment on the stability exists. 3. The GM decreased by 0.163 m and the KG increased by 0.173 m, compared with the values determined at the time of official sea trial. In no consideration of the free surface effects of liquid in the oil and fresh water tanks, no impediment on the stability exists. But, in consideration of the free surface effect, it may be regarded that some impediment exists.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.612-619
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• 2002

The dynamic behavior of Al-Mg alloys plasma was very unstable and this instability was closely related to the unstable motion of keyhole during laser irradiation. The keyhole fluctuated both in size and shape and its fluctuation period was about 440 ${\mu}{\textrm}{m}$. This instability has been estimated to be caused by the evaporation phenomena of metals with different boiling point and latent heats of vaporization. Therefore, the authors have conducted the spectroscopic diagnostics of plasma induced in the pulsed YAG laser welding of Al-Mg alloys in air and argon atmospheres. In the air environment, the identified spectra were atomic lines of Al, Mg, Cr, Mn, Cu, Fe and Zn, and singly ionized Mg line, as well as strong molecular spectrum of AlO, MgO and AIH. It was confirmed that the resonant lines of Al and Mg were strongly self-absorbed, in particular in the vicinity of pool surface. The self-absorption of atomic Mg line was more eminent in alloys containing higher Mg. These facts showed that the laser-induced plasma was relatively a low temperature and high density metallic vapor. The intensities of molecular spectra of AlO and MgO were different each other depending on the power density of laser beam. Under the low power density irradiation condition, the MgO band spectra were predominant in intensity, while the AlO spectra became much stronger in higher power density. In argon atmosphere the band spectra of MgO and AlO completely vanished, but AlH molecular spectra was detected clearly. The hydrogen source was presumably the hydrogen solved in the base Metal, absorbed water on the surface oxide layer or H$_2$ and $H_2O$ in the shielding gas. The temporal change in spectral line intensities was quite similar to the fluctuation of keyhole. The time average plasma temperature at 1 mm high above the surface of A5083 alloy was determined by the Boltzmann plot method of atomic Cr lines of different excitation energy. The obtained electron temperature was 3, 280$\pm$150 K which was about 500 K higher than the boiling point of pure aluminum. The electron number density was determined by measuring the relative intensities of the spectra1lines of atomic and singly ionized Magnesium, and the obtained value was 1.85 x 1019 1/㎥.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.44.1-44.17
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• 2018

Background: Coffee extract has been investigated by many authors, and many minor components of coffee are known, such as polyphenols, diterpenes (kahweol and cafestol), melanoidins, and trigonelline, to have anti-inflammatory, anti-oxidant, anti-angiogenic, anticancer, chemoprotective, and hepatoprotective effects. Therefore, it is necessary to know its pharmacological effect on hepatocytes which show the most active cellular regeneration in body. Methods: In order to determine whether coffee extract has a beneficial effect on the liver, 20 C57BL/6J mice were intraperitoneally injected once with dialyzed coffee extract (DCE)-2.5 (equivalent to 2.5 cups of coffee a day in man), DCE-5, or DCE-10, or normal saline (control), and then followed by histological observation and IP-HPLC (immunoprecipitation high performance liquid chromatography) over 24 h. Results: Mice treated with DCE-2.5 or DCE-5 showed markedly hypertrophic hepatocytes with eosinophilic cytoplasms, while those treated with DCE-10 showed slightly hypertrophic hepatocytes, which were well aligned in hepatic cords with increased sinusoidal spaces. DCE induced the upregulations of cellular proliferation, growth factor/RAS signaling, cellular protection, p53-mediated apoptosis, angiogenesis, and antioxidant and protection-related proteins, and the downregulations of NFkB signaling proteins, inflammatory proteins, and oncogenic proteins in mouse livers. These protein expression changes induced by DCE were usually limited to the range ± 10%, suggesting murine hepatocytes were safely reactive to DCE within the threshold of physiological homeostasis. DCE-2.5 and DCE-5 induced relatively mild dose-dependent changes in protein expressions for cellular regeneration and de novo angiogenesis as compared with non-treated controls, whereas DCE-10 induced fluctuations in protein expressions. Conclusion: These observations suggested that DCE-2.5 and DCE-5 were safer and more beneficial to murine hepatocytes than DCE-10. It was also found that murine hepatocytes treated with DCE showed mild p53-mediated apoptosis, followed by cellular proliferation and growth devoid of fibrosis signaling (as determined by IP-HPLC), and subsequently progressed to rapid cellular regeneration and wound healing in the absence of any inflammatory reaction based on histologic observations.

• Journal of Biomedical Engineering Research
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• v.19 no.4
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• pp.341-350
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• 1998

The accurate measurement of the femoral anteversion is important for the derotational osteotomy. To estimate femoral anteversion, following three major parameters are required; the neck axis, the long axis, and the knee axis. Conventional methods on the basis of 2D images are ambiguous to determine these major axes. As the femur has a complex 3 dimensional structure, the 3 dimensional model should be applied for accurate and reliable measurement of femoral anteversion. In this thesis, we model femur and define three parameters. The neck axis is defined from the femoral head and neck model. The long axis is determined from the cylindrical model of the femoral shaft. The knee axis is also determined from the model of femoral condyles. According to the definition of the femoral anteversion, the femoral anteversion is efficiently estimated from these models. 20 specimens were tested by the conventional 2D imaging method and 3D imaging method witch was developed by authors and the new 3D modeling method. The study provides accurate, fast and human factor free measurement for femoral anteversion.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.29-42
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• 2012

Recently, traffic congestion has become serious due to increase of private car usages. Carsharing or other innovative public transportation systems were developed to alleviate traffic congestion and carbon emissions. These measures can make the traffic environment more comfortable, and efficient. Cloud Transportation System (CTS) is a recent carsharing model. User can rent an electronic vehicles with various traffic information through the CTS. In this study, a concept, vision and scenarios of CTS are introduced. And, authors analyzed the location of CTS rental stations and estimated CTS demands. Firstly, we analyze the number of the population, employees, students and traffic volume in study areas. Secondly, the frequency and utilization time are examined. Demand for CTS in each traffic zone was estimated. Lastly, the CTS rental station location is determined based on the analyzed data of the study areas. Evaluation standard of the determined location includes accessibility and density of population. And, the number of vehicles and that of parking zone at the rental station are estimated. The result suggests that Haewoondae Square parking lot would be assigned 11 vehicles and 14.23 parking spaces and that Dongbac parking lot be assigned 7.9 vehicles and 10.29 parking spaces. Further study requires additional real-time data for CTS to increase accuracy of the demand estimation. And network design would be developed for redistribution of vehicles.

• Geophysics and Geophysical Exploration
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• v.9 no.3
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• pp.207-224
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• 2006

It has been widely known that the seismic piezo-cone penetration test (SCPTu) is one of the most useful techniques for investigating the geotechnical characteristics such as static and dynamic soil properties. As practical applications in Korea, SCPTu was carried out at two sites in Busan and four sites in Incheon, which are mainly composed of alluvial or marine soil deposits. From the SCPTu waveform data obtained from the testing sites, the first arrival times of shear waves and the corresponding time differences with depth were determined using the cross-over method, and the shear wave velocity $(V_S)$ profiles with depth were derived based on the refracted ray path method based on Snell's law. Comparing the determined $V_S$ profile with the cone tip resistance $(q_t)$ profile, both trends of profiles with depth were similar. For the application of the conventional CPTu to earthquake engineering practices, the correlations between $V_S$ and CPTu data were deduced based on the SCPTu results. For the empirical evaluation of $V_S$ for all soils together with clays and sands which are classified unambiguously in this study by the soil behavior type classification index $(I_C)$, the authors suggested the $V_S-CPTu$ data correlations expressed as a function of four parameters, $q_t,\;f_s,\;\sigma'_{v0}$ and $B_q$, determined by multiple statistical regression modeling. Despite the incompatible strain levels of the downhole seismic test during SCPTu and the conventional CPTu, it is shown that the $V_S-CPTu$ data correlations for all soils, clays and sands suggested in this study is applicable to the preliminary estimation of $V_S$ for the soil deposits at a part in Korea and is more reliable than the previous correlations proposed by other researchers.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.92-98
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• 2007

Introduction: The treatment of proximal humeral fracture is traditionally determined by Neer's classification system. The severely displaced three-part or four-part fracture is an indication for primary hemiarthroplasty. The current authors report the clinical results of 10 patients who received hemiarthroplasty for proximal comminuted fractures. The minimum follow-up period was 12 months. Materials and Methods: The current authors studied 10 patients who, between July 1999 and March 2005, each received hemiarthroplasty for a proximal humeral fracture of one shoulder. According to Neer's classification system, 5 of the patients had three-part fractures, and 5 of the patients had 4-part fractures. The mean interval between trauma and hemiarthroplasty was 6.1 days. The mean age of the 6 female and 4 male patients was 67.4 years(range: 56 to 76). Shoulder function was evaluated using the Constant score, the Simple Shoulder Test, and the modified UCLA score. Results: The mean Constant score was 51.4(range: 34 to 60). The mean modified SST score was 7.8 out of 12 tasks. Excluding the one patient who had also sustained an axillary artery rupture and a brachial plexus injury after the initial trauma, the mean Constant score for the remaining 9 patients was 53.5(range: 44 to 60), and the mean SST score was 7.2 tasks. The modified UCLA score averages for pain, function, and active forward flexion and strength were, respectively, 8.2($6{\sim}10$), 6.6($2{\sim}8$), and 6.9($4{\sim}8$). The total UCLA score was an average of 21.7($12{\sim}26$). Patients' the modified UCLA ratings were as follows: Excellent: 3, Good: 6, and Poor: 1. The patient with the poor outcome was the one who had also sustained the neurovascular injury. Patient's subjective satisfaction rating were as follows: Excellent: 2, Good: 7, and Poor: 1. Conclusion: Based on short term follow-up results, this study indicates that hemiarthroplasty is the treatment of choice for proximal humeral fractures on which it would be difficult to perform open reduction and internal fixation. Hemiarthroplasty is a useful treatment modality to prevent shoulder stiffness and to allow daily living tasks in elderly patients. However, restoration of muscle power and range of joint motion were not recovered satisfactorily.