• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.40 no.3
• /
• pp.217-226
• /
• 2022

In the view of the application of high-precision spatial information production, UAV (Umanned Aerial Vehicle)-Photogrammetry has a problem in that it lacks specific procedures and detailed regulations for quantitative quality verification methods or certification of captured images. In addition, test tools for UAV image quality assessment use only the GSD (Ground Sample Distance), not MTF (Modulation Transfer Function), which reflects image resolution and contrast at the same time. This fact makes often the quality of UAV image inferior to that of manned aerial image. We performed MTF and GSD analysis simultaneously using a siemens star to confirm the necessity of MTF analysis in UAV image quality assessment. The analyzing results of UAV images taken with different payload and sensors show that there is a big difference in σ_MTF values, representing image resolution and the degree of contrast, but slightly different in GSD. It concluded that the MTF analysis is a more objective and reliable analysis method than just the GSD analysis method, and high-quality drone images can only be obtained when the operator make images after judging the proper selection the sensor performance, image overlaps, and payload type. However, the results of this study are derived from analyzing only images acquired by limited sensors and imaging conditions. It is therefore expected that more objective and reliable results will be obtained if continuous research is conducted by accumulating various experimental data in related fields in the future.

• Journal of the Korean Orthopaedic Association
• /
• v.55 no.5
• /
• pp.366-373
• /
• 2020

The task of defining the concept of 'disability' has proven to be surprisingly difficult. The way disability is assessed in the world suggests that very different conceptions of disability are being presumed. It is very hard to suggest appropriate criteria for assessing a disability that accurately demonstrates the presence and measures the severity of the disability, with proven consistency and validity provided by the assessors consuming the time and cost that the society can afford. When a rigorous framework in disability assessment procedures is used, discretion is then considerably restricted. Limited discretion tends to produce more consistency and validity in the assessment but at the cost of ignoring the individual differences or exceptional circumstances. The disability approach among the categories of the disability assessment is both the oldest and the most commonly used strategy of disability assessment around the world. Most of the criteria of disability assessment in Korea belongs to this. The McBride's criteria for disability evaluations can be used to obtain the ratio of body impairment and work disability without spending too much time and is being applied in court. Nevertheless, there are many errors and controversies, and corrections are required. On the other hand, an improvement plan for a disability evaluation method in Korea is to supplement and use the McBride's disability assessment method, which is currently the most widely used. This review article describes the conception of disability and the assessment of disability, and introduces the models of the assessment of disability to determine if the application of the McBride's criteria of disability evaluation can be justified.

• Korean Journal of Construction Engineering and Management
• /
• v.22 no.4
• /
• pp.29-40
• /
• 2021

Recently, interest in Building Information Modeling (BIM) has increased globally, and 3D modeling is a start for the application of BIM at construction sites. However, while many studies have been conducted on the efficiency of 3D modeling focused on civil facilities, there is a lack of research on the earthwork BIM. In particular, since 3D slope often has complex shapes depending on the ground models, the efficiency method for 3D slope are needed. This study analyzed the interfaces and procedures of other software to find out what functions users need. Then the functions to enter intervals between 3D faces, select multiple ground models, and improve the interface are reflected on the developed system and is able to efficiently perform modeling with only five steps, and reduce the number of clicks and inputs. As a result of conducting the test to verify the efficiency, using the developed system made skilled users complete modeling at least 1.8 times faster and unskilled people at least 2.4 times faster than using other software. This is expected to perform 3D slope modeling more efficiently, as well as to contribute to the activation of future BIM adoption for housing construction projects.

• Journal of Conservation Science
• /
• v.38 no.2
• /
• pp.154-165
• /
• 2022

The color appearance of cultural heritage are essential factors for manufacturing technique interpretation, conservation treatment usage, and condition monitoring. Therefore, this study systematically established color reproduction procedures based on the digital color management system for the portrait of Gwon Eungsu. Moreover, various application strategies for recording and conserving the cultural heritage were proposed. Overall color reproduction processes were conducted in the following order: photography condition setting, standard color measurements, digital photography, color correction, and color space creation. Therefore, compared with the color appearance, the digital image applied to a camera maker profile indicated an average color difference of 𝜟10.1. However, the digital reproduction result based on the color management system exhibits an average color difference of 𝜟1.1, which is close to the color appearance. This means that although digital photography conditions are optimized, recording the color appearance is difficult when relying on the correction algorithm developed by the camera maker. Therefore, the digital color reproduction of cultural heritage is required through color correction and color space creation based on the raw digital image, which is a crucial process for documenting the color appearance. Additionally, the recording of color appearance through digital color reproduction is important for condition evaluation, conservation treatment, and restoration of cultural heritage. Furthermore, standard data of imaging analysis are available for discoloration monitoring.

• Journal of Aerospace System Engineering
• /
• v.16 no.4
• /
• pp.28-34
• /
• 2022

In 2021, Virgin Orbit converted a 747-400 aircraft into an air launch platform, and successfully launched it twice in February and July. Compared to the existing ground launch, interest in the air launch is increasing due to its great utility, such as its independence from the launch location or weather, cost reducing factor, shorter launch preparation time, and its benefit pursuant to altitude and speed. Additionally, as small satellites have similar performance to mid/large satellites in the past due to the miniaturization and precision of electronic equipment, small satellite launches are expected to dominate in the future. In this paper, institutional certification methods such as domestic, overseas, civilian and military airworthiness certification regulations/procedures are reviewed to ensure flight safety of aerial projectiles using large domestic civil aircraft, and applicable civil and military airworthiness certification technology standards are reviewed and analyzed. Additionally, we will review and suggest effective airworthiness certification application plans that reflect the reality, and present airworthiness certification standards (draft) for aerial launch vehicles, by analyzing applicable airworthiness certification technical standards when remodeling aerial launch vehicles.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.30 no.2
• /
• pp.71-90
• /
• 2021

The virtual patient dataset is a collection of diagnostic data from various sources acquired from a single patient into a coordinate system of three-dimensional visualization. Virtual patient dataset makes it possible to establish a treatment plan, simulate various treatment procedures, and create a treatment planning delivery device. Clinicians can design and simulate a patient's smile on the virtual patient dataset and select the optimal result from the diagnostic process. The selected treatment plan can be delivered identically to the patient using manufacturing techniques such as 3D printing, milling, and injection molding. The delivery of this treatment plan can be linked to the final prosthesis through mockup confirmation through provisional restoration fabrication and delivery in the patient's mouth. In this way, if the diagnostic data superimposition and processing accuracy during the manufacturing process are guaranteed, 3D digital smile design simulated in 3D visualization can be accurately delivered to the real patient. As a clinical application method of the virtual patient dataset, we suggest a decision-making method that can exclude occlusal adjustment treatment from the treatment plan through the digital occlusal pressure analysis. A comparative analysis of whole-body scans before and after temporomandibular joint treatment was suggested for adolescent idiopathic scoliosis patients with temporomandibular joint disease. Occlusal plane and smile aesthetic analysis based on the virtual patient dataset was presented when treating patients with complete dentures.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1996.06a
• /
• pp.75-87
• /
• 1996

This review is presented under the following headings: 1.Introduction 1.1 Brief review of the properties of AlN 1.2 Historical survey of work on ceramic and single crystal AlN 2.Thermochemical background 3.Crystal growth 4.Doping 5.Potential applications and future work The known properties of AlN which make it of interest for various are discussed briefly. The properties include chemical stability, crystal structure and lattice constants, refractive indices and other optical properties, dielectric constant, surface acoustic wave velocity and thermal conductivity. The history of work in single crystals, thin films and ceramics are outlined and the thermochemistry of AlN reviewed together with some of the relevant properties of aluminium and nitrogen; the problems encountered in growing crystals of AlN are shown to arise directly from these thermochemical relationships. Methods have been reported in the literature for growing AlN crystals from melts, solution and vapour and these methods are compared critically. It is proposed that the only practicable approach to the growth of AlN is by vapour phase methods. All vapour based procedures share the share the same problems: $.$the difficulty of preventing contamination by oxygen & carbon $.$the high bond energy of molecular nitrogen $.$the refractory nature of AlN (melting point~3073K at 100ats.) $.$the high reactivity of Al at high temperatures It is shown that the growth of epitactic layers and polycrystalline layers present additional problems: $.$chemical incompatibility of substrates $.$crystallographic mismatch of substrates $.$thermal mismatch of substrates The result of all these problems is that there is no good substrate material for the growth of AlN layers. Organometallic precursors which contain an Al-N bond have been used recently to deposit AlN layers but organometallic precursors gave the disadvantage of giving significant carbon contamination. Organometallic precursors which contain an Al-N bound have been used recently to deposit AlN layers but organometallic precursors have the disadvantage of giving significant carbon contamination. It is conclude that progress in the application of AlN to optical and electronic devices will be made only if considerable effort is devoted to the growth of larges, pure (and particularly, oxygen-free) crystals. Progress in applications of epi-layers and ceramic AlN would almost certainly be assisted also by the availability of more reliable data on the pure material. The essential features of any stategy for the growth of AlN from the vapour are outlined and discussed.

• Nuclear Engineering and Technology
• /
• v.26 no.3
• /
• pp.337-344
• /
• 1994

Enthalpy rise hot channel factor($F_{\Delta{H}}$$^{N}$) is one of the most limiting constraints in determining the fuel loading pattern(LP) for PWR's. In order to enhance the LP design flexibility without any changes of not only basic fuel specifications but also Technical Specifications and Operation Procedures, we apply the enrichment zoning concept to Westinghouse designed PWR's to flatten the rod power distributions within the fuel assembly and thus to reduce $F_{\Delta{H}}$$^{N}$. Enrichment zoning is described that each assembly consists of two different enrichment fuels ; the lower enriched fuels are located in positions which are expected to have the higher rod power and vice versa for the higher enriched fuels. As a result of unit assembly calculations to flatten the rod power distribution within the assembly, the appropriate enrichment difference is found to be 0.3~0.4w/o. Through core depletion calculations for the 18-month cycle of Kori Unit 4, the $F_{\Delta{H}}$$^{N}$ behavior in core with the enrichment zoning concept is investigated. A comparison with the reference case without the enrichment zoning results in a reduction in $F_{\Delta{H}}$$^{N}$ of approximately 1.5%.TEX>H/$^{N}$ of approximately 1.5%.

• Convergence Security Journal
• /
• v.22 no.4
• /
• pp.161-168
• /
• 2022

After the corona virus, as non-face-to-face services are activated, domain services that guarantee integrity by embedding sensing information of the Internet of Things (IoT) with block chain technology are expanding. For example, in areas such as safety and security using CCTV, a process is required to safely update firmware in real time and to confirm that there is no malicious intrusion. In the existing safe security processing procedures, in many cases, the person in charge performing official duties carried a USB device and directly updated the firmware. However, when private blockchain technology such as Hyperledger is used, the convenience and work efficiency of the Internet of Things environment can be expected to increase. This article describes scenarios in how to prevent vulnerabilities in the operating environment of various customers such as firmware updates and device changes in a non-face-to-face environment. In particular, we introduced the optimal blockchain technique for the Internet of Things (IoT), which is easily exposed to malicious security risks such as hacking and information leakage. In this article, we tried to present the necessity and implications of security management that guarantees integrity through operation applying block chain technology in the increasingly expanding Internet of Things environment. If this is used, it is expected to gain insight into how to apply the blockchain technique to guidelines for strengthening the security of the IoT environment in the future.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.23 no.4
• /
• pp.229-236
• /
• 2023

Background: Local anesthesia has been reliably used to control pain during dental procedures and is important in pediatric dentistry. However, children occasionally complain of prolonged numbness after dental treatment, leading to several problems. Studies conducted to reverse the effect of local anesthesia using phentolamine mesylate and photobiomodulation therapy (PBM) are encouraging but limited. PBM is a type of light therapy that utilizes visible and near-infrared non-ionizing electromagnetic spectral light sources. Hence, this study used this modality to compare the reversal of local anesthesia at two different wavelengths. This study compared the effect of PBM at 660 and 810 nm wavelengths on the reversal of soft tissue local anesthesia using a diode LASER in pediatric dentistry. Method: Informed consent and assent were obtained, and the participants were then divided randomly into three groups of 20 children each: control group-without LASER irradiation, LASER irradiation at 660 nm, and LASER irradiation at 810 nm. Sixty children aged 4-8 years with deciduous mandibular molars indicated for pulp therapy were administered an inferior alveolar nerve block. After 45 min of injection, a duration that was similar to the approximate duration of treatment, they were exposed to 660- and 810-nm LASER irradiation according to their groups until reversal of local anesthesia was achieved. The control group did not undergo LASER irradiation. The reversal of the soft tissue local anesthetic effect was evaluated using palpation and pin prick tests every 15 min, and the LASER irradiation cycle continued until reversal of the soft tissue local anesthesia was achieved. Results: A significant reduction of 55.5 min (27.6%) in the mean soft tissue local anesthesia reversal time was observed after the application of 810 nm wavelength PBM and 69 min (34.7%) after 660 nm wavelength LASER irradiation. Conclusion: PBM with a 660 nm wavelength was more effective in reducing the mean soft tissue local anesthesia reversal duration, and thus can be used as a reversal agent for soft tissue local anesthesia in pediatric dentistry.