• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.1
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• pp.64-73
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• 2015

Recently, the integrated utilization of technology with IT is in demand for the effectiveness of field management together with the prevention and prompt action on safety accident at construction site. In addition, the establishment of construction site support system is necessary to implement the securing of worker's safety, smooth work instruction, efficiency in construction, and others. Data standardization and network architecture were designed regarding data and sound information for data transmission between systems and management. These were to construct USFSS based on integrated VI-GNSS technology in this research. In the stability test of data for each system constructed through it, around 98% stability was secured between workers and for transfer vehicle system within underground structure and field server system in regards to the data transmission stability, around 100% stability was secured between field server system and control system, respectively. Also, in the sound transmission stability test, around 99% reliability could be secured with 1km distance as its standard in case of sound transmission from underground structure construction site to field office near the field through wireless FRS system.

• Journal of Ocean Engineering and Technology
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• v.34 no.5
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• pp.294-303
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• 2020

This study discusses data collection, calculation of wind and wave-induced resistance, and speed-power analysis of an 8,600 TEU container ship. Data acquisition system of the ship operator was improved to obtain the data necessary for the analysis, which was accomplished using SPA (Ship Performance Analysis, Park et al., 2019) in conformation with ISO15016:2015. From a previous operation profile of the container, the standard operating conditions of mean draft were 12.5 m and 13.6 m, which were defined with the mean stowage configuration of each condition. Model tests, including the load-variation test, were conducted to validate new ship performance and for the speed-power analysis. The major part of the added resistance of container ship is due to the wind. To check the reliability of wind-resistance calculation results, the resistance coefficients, added resistance, and speed-power analysis results using the Fujiwara regression formula (ISO15016:2015) and Computational fluid dynamics (Ryu et al., 2016; Jeon et al., 2017) analysis were compared. Wind speed and direction measured using an anemometer were used for wind-resistance calculation and the wave resistance was calculated using the wave-height and direction-data from weather information. Also, measured water temperature was used to calculate the increase in resistance owing to the deviation in water density. As a result, the SPA analysis using measured data and weather information was proved to be valid and able to identify the ship's resistance propulsion performance. Even with little difference in the air-resistance coefficient value, both methods provide sufficient accuracy for speed-power analysis. The differences were unnoticeable when the speed-power analysis results using each method were compared. Also, speed-power analysis results of the 8,600 TEU container ship in two draft conditions show acceptable trends when compared with the model test results and are also able to show power increase owing to hull fouling and aging. Thus, results of speed-power analysis of the existing 8,600 TEU container ship using the SPA program appropriately exhibit the characteristics of speed-power performance in deal conditions.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.2
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• pp.147-153
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• 2016

The lightning protection of information and communication facilities is very important factor to improve a reliability of the action of these equipment. Especially the transient potential rise of ground electrode being injected with the lightning current is to be a basic data of the dielectric strength for both power and communication facilities so that more accurate analysis should be required. The transient potential rise can be calculated from the ground impedance and the ground impedance is strongly dependent upon the shape of the ground electrode and the frequency-dependence of soil. The Debye's equation which is able to calculate the characteristics of dielectrics is used to analyze the frequency-dependent of soil. Also, the method to calculate the transient potential rise from the ground impedance is specified in this paper. In order to analyze the transient potential rise resulting from calculations with Debye's equation, TLM(transmission line method) and case of ${\rho}$(resistivity)-constant are simulated, respectively. The length of a horizontal ground electrode is 30 m and simulations were performed at 10, 100, $1000{\Omega}{\cdot}m$ with the standard lightning current waveform. In result, the transient potential rise of horizontal ground electrode calculating with Debye's equation is lower than it of other models.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.143-152
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• 2015

The 'Quality Competitiveness Index' (QCI) is defined as an quantitative and disinterested indicator that measures and compares the quality of products across the world. The purpose of this study is to suggest the 'Quality Competitiveness Assessment Model' (QCAM) and calculate QCI of a popular UHF RFID Label tag (Global ISO 18000-3C supported) available these days in a global apparel market. The model was based on KS-QEI(Korean Standard-Quality Excellence Index), and was composed with the following 4 evaluation categories, a process capability test, an environmental reliability test, a durability test and a design margin test. The QCI score can be calculated with the following formula, using the weighted arithmetic mean between a score of each evaluation category ($X_1$, $X_2$, $X_3$, $X_4$) and each weight($w_1$, $w_2$, $w_3$, $w_4$). The actual weights was determined by an result of AHP survey to which was conducted for the related Industry-University-Institute experts. The proposed index shows the results of comparisons with global competitor's products as well as the high-quality domestic RFID label tags. In addition, it will play an important role for manufacturers when developing their future products.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.425-431
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• 2019

Selected leafy vegetables, widely used for Korean Namul dishes, were heat-treated in different ways and their folate retention was investigated. The Lactobacillus casei method was applied for folate estimation and validated to ensure reliability of analytical data. The folate content in Namul highly varied, from 29.7 to $293.4{\mu}g/100g$, depending on the heating methods and the types of vegetables. Most of the Namul variants showed increased folate content on heat treatment. Frying yielded higher folate retention than the other cooking methods (blanching, steaming, baking, and panfrying), and pig weed showed the highest folate retention (3.3 times, $293.4{\mu}g/100g$). L. casei assay for folate estimation showed 95.7% recovery and relative standard deviations less than 2% for both reproducibility and repeatability, indicating good accuracy and precision. Quality of the folate assay was assured by monitoring a quality control chart and a proficiency test (z-score= -0.1) during the entire of study.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.2
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• pp.121-131
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• 2021

Magnesium (Mg) present in carbonate minerals as impurities has been used as a geochemical proxy to infer the environmental conditions where the minerals precipitated. The reliability of Mg geochemical proxies requires fundamental understanding of Mg incorporation into minerals based on accurate speciation of Mg ²⁺ in the crystal structure, which is determined mainly by application of X-ray absorption spectroscopy (XAS). However, high uncertainties are involved in interpreting the XAS spectra of minerals containing trace amount of Mg ²⁺. Because density function theory (DFT) can predict an XAS spectrum for a crystal structure, DFT calculations can reduce the uncertainties in the interpretation of the XAS spectrum. In this study, we calculated ab initio Mg K-edge absorption spectra of Mg silicates and (hydr)oxides based on DFT and analyzed the correlation between the calculated spectra and Mg structural parameters. Our ab initio Mg K-edge absorption spectra well reproduced the key features of the experimental spectra. The absorption-edge positions of the calculated spectra showed the weak positive correlation with the average Mg-O bond distance or Mg effective coordination number. The current study shows that DFT-based core-level spectroscopy method is a powerful tool in providing standard Mg K-edge spectra of diverse Mg minerals and determining the Mg chemical species within carbonate minerals.

• Asian Spine Journal
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• v.12 no.6
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• pp.1106-1116
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• 2018

Study Design: Prospective observational study. Purpose: To evaluate the disability domains relevant to Indian patients with low backache and propose a modified disability questionnaire for such patients. Overview of Literature: The Oswestry Disability Index (ODI) is a self-reported measurement tool that measures both pain and functional status and is used for evaluating disability caused by lower backache. Although ODI remains a good tool for disability assessment, from the Indian perspective questions related to weight lifting and sexual activity of ODI are questioned in some of the earlier studies. Activities of daily living in Indian patients vary substantially from those in other populations and include activities like bending forwards, sitting in floor and squatting which are not represented in the ODI. Methods: In this prospective observational study, a seven-step approach was used for the development of a questionnaire. Thirty patients were interviewed to identify the most challenging issue they faced while performing their daily activities (by free listing) and understand how important the questionnaire items were in terms of the standard ODI. Thus, a comprehensive disability questionnaire comprising 14 questions was developed and administered to 88 patients. Both qualitative (interviews) and quantitative methods (to establish the validity, reliability, and correlation with the Visual Analog Scale [VAS] and Rolland Morris disability questionnaire) were used to identify the 10 questions that best addressed the disability domains relevant to Indian patients. Results: According to free listing, four new questions pertaining to bending forward, sitting on the floor, walking on uneven surfaces, and work-related disabilities were included. In the second phase, wherein the questionnaire with 14 items was used, 56.8% patients did not answer the questions related to sexual activity, whereas 23.8% did not answer those related to walking on uneven surfaces. The modified questionnaire demonstrated good internal consistency (Cronbach's alpha=0.892) and correlation with the Rolland Morris questionnaire (Cronbach's alpha=0.850, p>0.05), as well as with the VAS score for disability (Cronbach's alpha=0.712, p>0.05) and pain (Cronbach's alpha=0.625, p>0.05). Conclusions: A modified disability questionnaire that was designed by adding two questions related to bending forward and work status and removing questions related to sexual activity and weight lifting or traveling (depending on the occupation) can help evaluate disability caused by back pain in Indian population.

• Explosives and Blasting
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• v.37 no.2
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• pp.22-30
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• 2019

On sites where explosives are used, the effects of noise and vibration produced by the blast wave are subject to a number of operational restrictions. Recently, the number of civil complaints has increased and the standard of environmental regulations on secure goods has been greatly tighten. Therefore, work is generally carried out by machine excavation in case of close proximity of safety thing. Machine excavation methods have the advantage as reducing noise and vibration compared to blasting methods, but depending on the conditions of rock intended to be excavated, they are sometimes less constructive than planned. In general, the closer a rock type is to hard rock, the less constructible it becomes. In this paper, we are going to explain the construction of a construction section with a close proximity to a safety thing using electronic detonators. While the project site was designed with a machine excavation methods due to the close(9.9m) proximity of safety thing(the railroad), construction using electronic detonators was reviewed as an alternative method for improving rate of advance time and construction efficiency when expose to hard rock. Through blasting using electronic detonators, construction and economic efficiency were maximized while minimizing impact on surrounding safety things. Because $HiTRONIC^{TM}$, which is produced by Hanwha, has innovative stability and high explosion reliability, it is able to explode with high-precision accuracy. Electronic detonators are widely used in construction sites of railway or highway, other urban burrowing areas and large limestone mines.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.404-412
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• 2019

The purpose of this study is to develop the usability evaluation contents based on the needs of different stakeholder's related to the usability of the product, and to derive the design direction and apply it as the evaluation standard by applying the product design based on the results. I created a stakeholder map for a fire detector product and identified stakeholders related to usability. Based on 3 factors(Physical, cognitive, emotional) of the usability evaluation, I conducted survey on the building users and the building managers who have different requirements. There are 12 directions (ease of installation, durability, maintainability, additional functionality, effectiveness, attractiveness, visibility, consistency of information, environmental harmony, consistency, Image suitability, reliability). Through weighted analysis of three usability evaluation factors, I found factors were ranked in the same order of importance, but they were different in importance figure. Based on the results of the survey, overall product usability aspects were improved but effectiveness and environmental coordination aspects needed to be improved.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.69-79
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• 2019

The coastal area forms various sedimentary layers according to the environmental conditions such as the topography and geological features of the upper region of the river, ocean currents, and river mouth. Therefore, identifying the characteristics of the marine clay deposited in the coastal area plays a key role in the investigation of the formation of soft ground. In general, alluvial grounds are formed by a variety of factors such as changes in topography and natural environment, they have very diverse qualities depending on the deposited region or sedimentation conditions. The most important thing for the construction of social infrastructures in soft ground areas is economical and efficient treatment of soft ground. In this study, the author collected data from diverse laboratory and field tests on five areas in western and southern offshore with relatively high reliability, and then statistically analyzed them, thereby presenting standard constants for construction design. Correlation between design parameters such as over consolidation ratio, preconsolidation pressure was analyzed using linear and non-linear regression analyses. Also, proposed distribution characteristics of design parameters in consideration of each region's uncertainty through statistical analyses such as normality verification, outlier removal.