• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.197-208
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• 2022

The existence of shallow bedrock and the desire to use underground space necessitate the use of blasting methods. The standard blasting method under water after drilling is associated with certain technical difficulties, including reduced detonation power, the use of a fixed charge per delay, and decoupling. However, there is no blasting method to replace the existing blasting method. In this paper, a dry hole charged with ANFO blasting is assessed while employing a dry hole pumping system to remove water from the drill borehole. Additional standard blasting is also utilized to compare the blasting performances of the two methods. The least-squares linear regression method is adopted to analyze the blasting vibration velocity quantitatively using the measured vibration velocity for each blasting method and the vibration velocity model as a function of the scaled distance. The results show that the dry hole charged with ANFO blasting will lead to greater damping of the blasting vibration, more energy dissipation to crush the surrounding rock, and closer distances for the allowable velocity of the blasting vibration. Also, standard blasting shows much longer influencing distances and a wider range of the blasting pattern. The pilot test confirms the blasting efficiency of dry hole charged with ANFO blasting.

• Korean Journal of Construction Engineering and Management
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• v.24 no.4
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• pp.3-13
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• 2023

The purpose of this study is to compare and analyze the performance and work productivity of wet type pavement cutters and sludge suction type pavement cutters (hereinafter referred to as automatic pavement cutters) developed to reduce scattering dust. We first investigated the development status of wet type manual pavement cutters that are mainly used in Korea and automatic pavement cutters, and analyzed the pavement cutting work in detail. And the standard cutting performance was derived by measuring the cutting time by depth by applying the two equipment to the test bed under the same conditions. However, there is a limitation that the data measured in the test bed does not reflect the various variables of the actual pavement cutting site. Therefore, in this study, data was collected through field surveys, and the correlation between cutting distance and time was analyzed, and then a model for calculating the productivity of pavement cutters was presented through simple regression analysis. As a result of comparative analysis of the values derived from the regression equation with the standard cutting performance derived from the test bed, the cutting performance derived through the regression equation showed a similar trend to the standard cutting performance. Finally, we verified the usability of the automated pavement cutter developed by qualitatively analyzing three tasks that are difficult to measure quantitatively but affect productivity.

• Journal of Life Science
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• v.34 no.4
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• pp.264-270
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• 2024

This study is conducted to analyze environmental factors that affect the ecology of boreal digging frog and use them as basic data for selecting (or creating) suitability of alternative habitats for survival and monitoring method from 2020 to 2022 after boreal digging frog were relocated to the alternative habitats in 2019. Analyzing the environment of the alternative habitats showed that the criteria suited the followings: distance from wetlands, grasslands and rivers was within 5 m, the low-rise grassland was 6,000 m², soft soil was at a depth of ≥20 cm, and the area of permanent wetlands was 5,000 m² wide. As a result of the correlation analysis between meteorological factors and population (n) and breeding, there was a significant correlation between rainfalls and breeding (p<0.01). During the monitoring, it was confirmed that the SVL (Snout-Vent Length) and BM (Body Mass) of the translocated population were maintained (p>0.05), and it was found that the proximity of the habitat and spawning pond, securing food space (grasslands), soil quality, and wetlands could function as an alternative habitat if conditions were met. As a result of analyzing the meteorological factors affecting the population of boreal digging frog, the SVL had a statistical impact on the minimum temperature, maximum temperature, relative humidity, and the rainfall (p<0.05). In the case of breeding, rainfall was found to be affected (p<0.01), and the population was statistically affected by the average temperature, minimum temperature, and relative humidity (p<0.05).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.2
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• pp.1-14
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• 2024

The most optimal route-search algorithm thus far has introduced a method of applying node labels and link labels. Node labels consider two nodes simultaneously in the optimal route-search process, while link labels consider two links simultaneously. This study proposes a turn-label-based optimal route-search technique that considers two turns simultaneously in the process. Turn-label-based optimal route search guarantees the optimal solution of dynamic programming based on Bellman's principle as it considers a two-turn search process. Turn-label-based optimal route search can accommodate the advantages of applying link labels because the concept of approaching the limit of link labels is applied equally. Therefore, it is possible to reflect rational cyclic traffic where nodes allow multiple visits without expanding the network, while links do not allow visits. In particular, it reflects the additional cost structure that appears in two consecutive turns, making it possible to express the structure of the travel-cost function more flexibly. A case study was conducted on the metropolitan urban railway network consisting of transportation card terminal readers, aiming to examine the scalability of the research by introducing parameters that reflect psychological resistance in travel with continuous pedestrian transfers into turn label optimal path search. Simulation results showed that it is possible to avoid conservative transfers even if the travel time and distance increase as the psychological resistance value for continuous turns increases, confirming the need to reflect the cost structure of turn labels. Nevertheless, further research is needed to secure diversity in the travel-cost functions of road and public-transportation networks.

• Coupled systems mechanics
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• v.13 no.3
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• pp.201-217
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• 2024

This study aims to develop a new model to obtain the minimum area in circular isolated footings with eccentric column taking into account that the surface in contact with the ground works partially in compression, i.e., a part of the contact area of the footing is subject to compression and the other there is no pressure (pressure zero). The new model is formulated from a mathematical approach based on a minimum area, and it is developed by integration to obtain the axial load "P", moment around the X axis "M_x" and moment around the Y axis "M_y" in function of σ_max (available allowable soil pressure) R (radius of the circular footing), α (angle of inclination where the resultant moment appears), y₀ (distance from the center of the footing to the neutral axis measured on the axis where the resultant moment appears). The normal practice in structural engineering is to use the trial and error procedure to obtain the radius and area of the circular footing, and other engineers determine the radius and area of circular footing under biaxial bending supported on elastic soils, but considering a concentric column and the contact area with the ground works completely in compression. Three numerical problems are given to determine the lowest area for circular footings under biaxial bending. Example 1: Column concentric. Example 2: Column eccentric in the direction of the X axis to 1.50 m. Example 3: Column eccentric in the direction of the X axis to 1.50 m and in the direction of the Y axis to 1.50 m. The new model shows a great saving compared to the current model of 44.27% in Example 1, 50.90% in Example 2, 65.04% in Example 3. In this way, the new minimum area model for circular footings will be of great help to engineers when the column is located on the center or edge of the footing.

• Journal of the Korea Society of Computer and Information
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• v.29 no.7
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• pp.11-20
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• 2024

In this paper, we propose the BAG (Bit-width Aware Generator) and the Intermediate Layer Knowledge Distillation using Channel-wise Attention to reduce the knowledge gap between a quantized network, a full-precision network, and a generator in GDFQ (Generative Data-Free Quantization). Since the generator in GDFQ is only trained by the feedback from the full-precision network, the gap resulting in decreased capability due to low bit-width of the quantized network has no effect on training the generator. To alleviate this problem, BAG is quantized with same bit-width of the quantized network, and it can generate synthetic images, which are effectively used for training the quantized network. Typically, the knowledge gap between the quantized network and the full-precision network is also important. To resolve this, we compute channel-wise attention of outputs of convolutional layers, and minimize the loss function as the distance of them. As the result, the quantized network can learn which channels to focus on more from mimicking the full-precision network. To prove the efficiency of proposed methods, we quantize the network trained on CIFAR-100 with 3 bit-width weights and activations, and train it and the generator with our method. As the result, we achieve 56.14% Top-1 Accuracy and increase 3.4% higher accuracy compared to our baseline AdaDFQ.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.2
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• pp.113-122
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• 2024

The gradual teeth wear with age is a natural phenomenon, but excessive wear beyond physiological levels can lead to vertical dimension loss, occlusal imbalance, temporomandibular joint disorders, and periodontal disease. In such cases, prosthodontic restoration becomes necessary emphasizing the importance of appropriate vertical dimension increase and stable occlusion in central relation (CR). In this case, a 74-year-old patient with clenching and grinding habit had severe teeth wear and after assessing interocclusal distance, wear degree, pronunciation, and facial profile, it was decided to perform full-mouth fixed prosthesis restoration with a 4 mm vertical dimension increase. And the significantly displaced Maximum Intercuspal Position (MICP) caused by parafunctional movements was re-established as a stable mutually protective occlusal relationship at centric relation and after a successful 4 months adaptation to provisional restorations, the final prosthesis was fabricated. During 4months of observation periods, stable occlusion in central relation and mutual protection occlusal relationships were maintained and the patient was satisfied with function and aesthetics, leading to this report.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.679-686
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• 2012

KTX step 1 April 2004, after the opening, the second phase of the project was opened in November 2010. High-speed rail after the opening and continue to increase the demand of high-speed rail, Have the speed of competitive advantage compared too the means of transportation. The opening of these high-speed rail has led to changes of the move, the company's position, and the spatial structure of the population of reorganization, such as the social, economic, transportation. In this study, survey data using the High Speed Rail Station EMME/2 of the program to take advantage of the 2-Dimentional Blancing trip distribution to investigate the passage through the trip distribution by the estimation of the parameters of the model to estimate the distribution of the means of access and high-speed rail station to reproduce and Analysis of the results by means of access parameters (${\theta}$) autos 0.0395, buses 0.0390, subway 0.0650, taxi 0.0415, the frequency distribution (Trip Length Frequency Distribution: TLFD) were analyzed survey data value model with the results of comparing $R^2$ cars analysis and model values similar survey data 0.909 bus 0.923, subway 0.745 to 0.922, taxi, F test P value analysis is smaller than 0.05 at the 95% confidence level as a note that was judged to have been. Trip frequency distribution analysis, but in the future, set the unit to 5km-trip frequency distribution middle zone Units from small zone units (administrative district) segmentation research is needed, and can reflect the trip distance 0~5 km interval combined function to take advantage of the gravity model and the 3-Dimentional Blancing applied research is needed to be considered.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.571-580
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• 2011

The purpose of this study was to evaluate the effects of secondary task such as sending text message (STM) and searching navigation (SN) using the variable indicating control of vehicle ((Medial-Lateral Coefficient of Variation, MLCV), (Anterior-Posterior Coefficient of Variation, APCV)) and motion signal (Jerk-Cost function, JC). Participants included 50s taxi drivers; 14 males and 14 females. Participants were instructed to keep a certain distance (30m) from the car ahead with constant speed (80km/hr or 100km/hr). Experiement consisted of driving alone for 1minute and driving with secondary task for 1minute. Both MLCV and APCV were significantly increased during Driving + Sending Text Message(STM) and Driving + Searching Navigation(SN) than Driving only. Also, JC was increased during Driving + STM and Driving + SN than Driving only. In this study, we found that even in the experts group who are taxi driver and have 25 years driving experience, the smoothness of motion is decreased and the control of vehicle is disturbed when they were performing secondary tasks like sending text message or searching navigation.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.357-363
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• 2013

Purpose: To investigate the visual function with prescription swimming goggles. Methods: 15 university students (mean age: $22{\pm}1.54$ years) participated, with a mean distance refractive error of RE: S-1.67 D/C-0.40 D, LE: S-1.70D/C-0.37 D. Inclusion criteria were no ocular pathology, able to wear soft contact lenses to correct their refractive error to emmetropia and able to swim. Participants were fitted with contact lenses to correct all ametropia. Subjective evaluation for satisfaction of visual acuity, asthenopia and balance were also measured using a questionnaire while wearing swimming goggles with cylinder (C+1.50 D, Ax $90^{\circ}$) compared with plano sphere outside the swimming pool area. Visual acuity was assessed using the same ETDRS chart. The prescription swimming goggles powers were assessed in random order and ranged in power from S+3.00 D to S-3.00 D in 0.50 D steps. Results: Subjective evaluation was significantly worse for the swimming goggles with cylinder than for the plano powered goggles for all 3 questions, visual acuity, asthenopia and balance. Visual acuity were significantly affected by the different power of the swimming goggles (p<0.05), but there was no significant difference between the in-air in-clinic and underwater in-swimming pool measures (p=0.173). However, visual acuity measured in the clinic was significantly better than underwater for some swimming goggle powers (+3.00, +1.00, +0.50, 0, -1.00 and -2.00 D). Conclusions: Wearing swimming goggles underwater may degrade the visual acuity compared to within air but as the difference is less than 1 line of Snellen acuity, and it is unlikely to result in significant real-life effects. Having an incorrect cylinder correction was found to be detrimental resulting in lower score of satisfaction. Considering slippery floor of swimming pool area, it can be a potential risk factor. Therefore, it is important to correct any refractive error in addition to astigmatism for swimming goggle.