• Journal of Ocean Engineering and Technology
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• v.33 no.3
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• pp.259-271
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• 2019

It is important to obtain reasonable predictions of the extent of the damage during maritime accidents such as ship collisions and groundings. Many fracture models based on different mechanical backgrounds have been proposed and can be used to estimate the extent of damage involving ductile fracture. The goal of this study was to compare the damage extents provided by some selected fracture models. Instead of performing a new series of material constant calibration tests, the fracture test results for the ship building steel EH36 obtained by Park et al. (2019) were used which included specimens with different geometries such as central hole, pure shear, and notched tensile specimens. The test results were compared with seven ductile fracture surfaces: Johnson-Cook, Cockcroft-Latham-Oh, Bai-Wierzbicki, Modified Mohr-Coulomb, Lou-Huh, Maximum shear stress, and Hosford-Coulomb. The linear damage accumulation law was applied to consider the effect of the loading path on each fracture surface. The Swift-Voce combined constitutive model was used to accurately define the flow stress in a large strain region. The reliability of these simulations was verified by the good agreement between the axial tension force elongation relations captured from the tests and simulations without fracture assignment. The material constants corresponding to each fracture surface were calibrated using an optimization technique with the minimized object function of the residual sum of errors between the simulated and predicted stress triaxiality and load angle parameter values to fracture initiation. The reliabilities of the calibrated material constants of B-W, MMC, L-H, and HC were the best, whereas there was a high residual sum of errors in the case of the MMS, C-L-O, and J-C models. The most accurate fracture predictions for the fracture specimens were made by the B-W, MMC, L-H, and HC models.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.9
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• pp.3138-3151
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• 2022

Traffic safety and congestion are becoming more and more serious, especially the frequent occurrence of traffic accidents, which have caused great casualties and economic losses. Cellular Vehicle to Everything (C-V2X) can assist in safe driving and improve traffic efficiency through real-time information sharing and communication between vehicles. All vehicles communicate directly with Base Stations (BS), which will increase the base station load. And when the communicating vehicles are too far apart, too fast or there are obstacles in the communication path, the communication link can be unstable or even interrupted. Therefore, choosing an effective and reliable multi-hop relay-assisted Vehicle to Vehicle (V2V) communication can not only reduce the base station load and improve the system throughput but also expand the base station coverage and improve the communication quality of edge vehicles. Therefore, a communication area division scheme based on regular hexagon segmentation technology is proposed, a relay-assisted V2V communication mechanism is designed for the divided communication areas, and an efficient communication link is constructed by selecting the best relay node. Simulation results show that the scheme can improve the throughput of the system by nearly 55% and enhance the robustness of the V2V communication link.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.285-291
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• 2022

In 1951, Colin Russell Austin and Min Chueh Chang identified "capacitation", a special process involving ejaculated spermatozoa in the female reproductive tract. Capacitation is a phenomenon that occurs in vivo, but almost all knowledge of capacitation has been obtained from in vitro studies. Therefore, numerous trials have been performed to establish in vitro capacitation methods for various studies on reproduction. Although a series of studies have been conducted to develop an optimal protocol for inducing capacitation, most have focused on identifying the appropriate chemical compounds to induce the capacitation of boar spermatozoa in vitro. Therefore, the purpose of this study was to identify the optimal incubation time for inducing capacitation in vitro. Duroc semen was incubated for various periods (60, 90, and 120 min) to induce capacitation. Sperm function (sperm motility, motion kinematic parameters, and capacitation status) was evaluated. The results showed that total sperm motility, rapid sperm motility, progressive sperm motility, curvilinear velocity, and average path velocity significantly decreased in a time-dependent manner. However, the capacitation status did not show any significant changes. Taken together, these results indicate that an incubation time of more than 60 min suppresses sperm motility and motion kinematic parameters. Therefore, we suggest that 60 min may be the best incubation time to induce capacitation without negative effects on sperm motility and motion kinematics in boar spermatozoa in vitro.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2140-2156
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• 2023

The Wireless Sensor Network (WSN), is constructed out of teeny-tiny sensor nodes that are very low-cost, have a low impact on the environment in terms of the amount of power they consume, and are able to successfully transmit data to the base station. The primary challenges that are presented by WSN are those that are posed by the distance between nodes, the amount of energy that is consumed, and the delay in time. The sensor node's source of power supply is a battery, and this particular battery is not capable of being recharged. In this scenario, the amount of energy that is consumed rises in direct proportion to the distance that separates the nodes. Here, we present a Hybrid Firefly Glow-Worm Swarm Optimization (HF-GSO) guided routing strategy for preserving WSNs' low power footprint. An efficient fitness function based on firefly optimization is used to select the Cluster Head (CH) in this procedure. It aids in minimising power consumption and the occurrence of dead sensor nodes. After a cluster head (CH) has been chosen, the Glow-Worm Swarm Optimization (GSO) algorithm is used to figure out the best path for sending data to the sink node. Power consumption, throughput, packet delivery ratio, and network lifetime are just some of the metrics measured and compared between the proposed method and methods that are conceptually similar to those already in use. Simulation results showed that the proposed method significantly reduced energy consumption compared to the state-of-the-art methods, while simultaneously increasing the number of functioning sensor nodes by 2.4%. Proposed method produces superior outcomes compared to alternative optimization-based methods.

• Journal of Creative Information Culture
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• v.5 no.3
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• pp.345-353
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• 2019

Several studies have been proposed to improve storage space efficiency by expressing binary trie data structure as a linear binary bit string. Compact binary tree approach generated using one binary trie increases the key search time significantly as the binary bit string becomes very long as the size of the input key set increases. In order to reduce the key search range, a hierarchical compact binary tree technique that hierarchically expresses several small binary compact trees has been proposed. The search time increases proportionally with the number and length of binary bit streams. In this paper, we generate several binary compact trees represented by full binary tries hierarchically. The search performance is improved by allowing a path for the binary bit string corresponding to the search range to be determined through simple numeric conversion. Through the performance evaluation using the worst time and space complexity calculation, the proposed method showed the highest performance for retrieval and key insertion or deletion. In terms of space usage, the proposed method requires about 67% ~ 68% of space compared to the existing methods, showing the best space efficiency.

• The Journal of Advanced Prosthodontics
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• v.15 no.6
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• pp.290-301
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• 2023

PURPOSE. The study aimed to determine the influence of implant angulation on the trueness of multi-unit implant impressions taken through different techniques and strategies. MATERIALS AND METHODS. As reference models, three partially edentulous mandibular models (Model 1: No angulation; Model 2: No angulation for #33, 15-degree distal angulation for #35 and #37; Model 3: No angulation for #33, 25-degree distal angulation for #35 and #37) were created by modifying the angulations of implant analogues. Using a lab scanner, these reference models were scanned. The obtained data were preserved and utilized as virtual references. Three intraoral scanning (IOS) strategies: IOS-Omnicam, ISO-Quadrant, and IOS-Consecutive, as well as two traaditional techniques: splinted open tray (OT) and closed tray (CT), were used to create impressions from each reference model. The best-fit alignment approach was used to sequentially superimpose the reference and test scan data. Computations and statistical analysis of angular (AD), linear (LD), and 3D deviations (RMS) were performed. RESULTS. Model type, impression technique, as well as interaction factor, all demonstrated a significant influence on AD and LD values for all implant locations (P < .05). The Model 1 and SOT techniques displayed the lowest mean AD and LD values across all implant locations. When considering interaction factors, CT-Model 3 and SOT-Model 1 exhibited the highest and lowest mean AD and LD values, respectively. Model type, impression technique, and interaction factor all revealed significant effects on RMS values (P ≤ .001). CT-Model 3 and SOT-Model 1 presented the highest and lowest mean RMS values, respectively. CONCLUSION. Splinted-OT and IOS-Omnicam are recommended for multi-unit implant impressions to enhance trueness, potentially benefiting subsequent manufacturing stages.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.247-256
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• 2024

The glass series modified by tungsten oxide was created using the compounds (75-x) B₂O₃- 10SrCO₃- 8TeO₂- 7ZnO - xWO₃, where x = 0, 1, 5, 10, 22, 27, 34, and 40% mole percentage. A UV-visible spectrophotometer and thermogravimetric-differential thermal analysis (TG-DTA) methods were employed to characterize the specimen's optical and phase transition attributes, respectively. The mass-attenuation coefficient (AC) of all created glasses from BSTZW0 to BSTZ7 was estimated using Geant4 code from 0.05 to 3 MeV and compared to the XCOM software results, with a relative difference of less than 2% between the two results. The increase of WO₃ percentage lead to an increase in the Linear-AC at each studied energy, and this is mainly due to the fact that the higher the percentage of WO₃ in the glass increases its density which causes an increase in the Linear-AC, so an energy of 0.06 MeV, as an example, the values of the Linear-AC was 4.009, 4.509, 5.442, 6812, 8.564, 9.856, 10.999 and 11.628 cm^-1 form BSTZW0 too BSTZW7, respectively. The Half-VL (value layer), Mean-FP (free path), Tenth-VL, and Radiation attenuation performance (RAP) were also calculated for the current BSTZW-glass samples and revealed that BSTZW7 had the best gamma ray attenuation performance at all discussed energies when compared to other studied glass samples.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3378-3384
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• 2024

Investigations were conducted on the addition of barium's impact on the radiation shielding and physical attributes of five different glasses, designated S1-S5, with varying BaO contents. Using two point sources namely Co⁶⁰ and Cs¹³⁷ along with a scintillation detector [NaI(TL)], experimental measurements were made of the shielding parameters of γ-rays, namely the effective atomic number (Z_eff), electron density (N_el), half-value layer (HVL), linear attenuation coefficient (μ), mass attenuation coefficient (μ_m), mean free path (λ), and radiation protection effectiveness at the energies of 0.664, 1.177, and 1.334 MeV, and comparisons made with recently considered glasses as well as frequently employed materials for γ-ray shielding. The results show that the examined glasses' physical and radiation shielding qualities are improved by the addition of BaO. The μ values increased from 0.245 to 0.275 cm^-1 (0.662 MeV), from 0.174 to 0.198 cm^-1 (1.173 MeV), and from 0.161 to 0.189 (1.332 MeV). The observed values of HVL decreased from 2.83, 3.98, and 4.3 cm to 2.5, 3.5, and 3.62 cm at 0.662, 1.173, and 1.332 MeV, respectively, for the samples S1 and S5. In addition, the S5 glass sample was determined to have the best protection against photon among all the samples that were evaluated, as well as against recently considered glasses and those materials often utilized for gamma-ray shielding purposes.

• Asia pacific journal of information systems
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• v.21 no.4
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• pp.1-25
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• 2011

Internet-based commerce has undergone an explosive growth over the past decade as consumers today find it more economical as well as more convenient to shop online. Nevertheless, the shift in the common mode of shopping from offline to online commerce has caused consumers to have worries over such issues as private information leakage, online fraud, discrepancy in product quality and grade, unsuccessful delivery, and so forth, Numerous studies have been undertaken to examine the role of perceived risk as a chief barrier to online purchases and to understand the theoretical relationships among perceived risk, trust and purchase intentions, However, most studies focus on empirically investigating the effects of trust on perceived risk, with little attention devoted to the effects of perceived risk on trust, While the influence trust has on perceived risk is worth studying, the influence in the opposite direction is equally important, enabling insights into the potential of perceived risk as a prohibitor of trust, According to Pavlou (2003), the primary source of the perceived risk is either the technological uncertainty of the Internet environment or the behavioral uncertainty of the transaction partner. Due to such types of uncertainty, an increase in the worries over the perceived risk may negatively affect trust, For example, if a consumer who sends sensitive transaction data over Internet is concerned that his or her private information may leak out because of the lack of security, trust may decrease (Olivero and Lunt, 2004), By the same token, if the consumer feels that the online merchant has the potential to profit by behaving in an opportunistic manner taking advantage of the remote, impersonal nature of online commerce, then it is unlikely that the merchant will be trusted, That is, the more the probable danger is likely to occur, the less trust and the greater need to control the transaction (Olivero and Lunt, 2004), In summary, a review of the related studies indicates that while some researchers looked at the influence of overall perceived risk on trust level, not much attention has been given to the effects of different types of perceived risk, In this context the present research aims at addressing the need to study how trust is affected by different types of perceived risk, We classified perceived risk into six different types based on the literature, and empirically analyzed the impact of each type of perceived risk upon consumer trust in an online merchant and further its impact upon purchase intentions. To meet our research objectives, we developed a conceptual model depicting the nomological structure of the relationships among our research variables, and also formulated a total of seven hypotheses. The model and hypotheses were tested using an empirical analysis based on a questionnaire survey of 206 college students. The reliability was evaluated via Cronbach's alphas, the minimum of which was found to be 0.73, and therefore the questionnaire items are all deemed reliable. In addition, the results of confirmatory factor analysis (CFA) designed to check the validity of the measurement model indicate that the convergent, discriminate, and nomological validities of the model are all acceptable. The structural equation modeling analysis to test the hypotheses yielded the following results. Of the first six hypotheses (H1-1 through H1-6) designed to examine the relationships between each risk type and trust, three hypotheses including H1-1 (performance risk ${\rightarrow}$ trust), H1-2 (psychological risk ${\rightarrow}$ trust) and H1-5 (online payment risk ${\rightarrow}$ trust) were supported with path coefficients of -0.30, -0.27 and -0.16 respectively. Finally, H2 (trust ${\rightarrow}$ purchase intentions) was supported with relatively high path coefficients of 0.73. Results of the empirical study offer the following findings and implications. First. it was found that it was performance risk, psychological risk and online payment risk that have a statistically significant influence upon consumer trust in an online merchant. It implies that a consumer may find an online merchant untrustworthy if either the product quality or the product grade does not match his or her expectations. For that reason, online merchants including digital storefronts and e-marketplaces are suggested to pursue a strategy focusing on identifying the target customers and offering products that they feel best meet performance and psychological needs of those customers. Thus, they should do their best to make it widely known that their products are of as good quality and grade as those purchased from offline department stores. In addition, it may be inferred that today's online consumers remain concerned about the security of the online commerce environment due to the repeated occurrences of hacking or private information leakage. Online merchants should take steps to remove potential vulnerabilities and provide online notices to emphasize that their website is secure. Second, consumer's overall trust was found to have a statistically significant influence on purchase intentions. This finding, which is consistent with the results of numerous prior studies, suggests that increased sales will become a reality only with enhanced consumer trust.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.253-261
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• 2002

This study was carried out to investigate the semen characteristic, motility and viability and sperm motion characteristic by CASA test for establishing the Jindo-dog's semen freezing system. The results obtained are as follow: 1. The semen was collected 63 times. Average volume of semen, concentration of sperm, total number of sperm, progressive motility and viability were 3.8 $m\ell$ 145.6$\times$10$^{6}$ cells/$m\ell$, 396.2 x10$^{8}$ cells, 79.7% and 89.5%, respectively. Also, Fawn (Yellow) Jindo-dog comparing with White Jindo-dog showed better concentration of sperm, total number of sperm, progressive motility and viability. Among all dogs, the results of No. 2 Fawn Jindo-dog were the best. 2. The average progressive motility and viability of semen from 46 times were 73.5%, 82.3% before freezing and 51.1%, 64.9% after freezing. So, the freezing of semen has affected the progressive motility and viability. The progressive motility and viability of Fawn Jindo-dog's semen, before and after freezing, were better than White Jindo-dog. And No. 2 Fawn Jindo-dog showed the best results and showed significantly different among all dogs (P<0.05). 3. The 44 times-tested .esults by CASA system were as follow; MOT (motility) 65.6%. PROG (progressive motility) 54.8%, VAP (average path velocity) 75.3 ${\mu}{\textrm}{m}$/sec, VCL (curve linear velocity) 90.0 ${\mu}{\textrm}{m}$/sec, VSL (straight-line velocity) 69.4 ${\mu}{\textrm}{m}$/sec and ALH (amplitude of lateral head displacement) 4.4 ${\mu}{\textrm}{m}$. Although the motion characteristic of frozen semen were not significantly different between White and Fawn Jindo-dog, No. 2 Fawn Jindo-dog showed the best results and was significantly different among all dogs (P<0.05). 4. The success rate of frozen semen production between White and Fawn Jindo-dog were 43% (13/28), 94% (33/35), respectively, and the total success rate was 73% (46/63). The freezing-ability of Fawn Jindo-dog's semen was better than the other. Conclusively, the present results indicated that the characteristic and motility of Jindo-dog') semen were suitable for processing frozen semen, artificial insemination and mass production system. Also, the selection of suitable dog-breed was so important because the characteristic and freezing-ability of semen were significantly different between White and Fawn Jindo-dogs and among all individual dogs.