• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.171-178
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• 2024

Exercises using a Balance Board (BB) are effective in developing balance, strengthening core muscles, and improving physical fitness and concentration. In particular, the Smart Balance Board (SBB), which integrates with various digital content, provides appropriate feedback compared to traditional balance boards, maximizing the effectiveness of the exercise. However, most systems only offer visual and auditory feedback, failing to evaluate the impact on user engagement, interest, and the accuracy of exercise postures. This study proposes an Immersive Smart Balance Board (I-SBB) that utilizes multiple sensors to enable training with various feedback mechanisms and precise postures. The proposed system, based on Arduino, consists of a gyro sensor for measuring the board's posture, a communication module for wired/wireless communication, an infrared sensor to guide the user's foot placement, and a vibration motor for tactile feedback. The board's posture measurements are smoothly corrected using a Kalman Filter, and the multi-sensor data is processed in real-time using FreeRTOS. The proposed I-SBB is shown to be effective in enhancing user concentration and engagement, as well as generating interest, by integrating with diverse content.

• Journal of Korean Society of Forest Science
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• v.113 no.3
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• pp.361-371
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• 2024

This study was conducted to develop models of the xylem volume utilization rate and merchantable log utility rate of the Japanese larch (Larix kaempferi [Lamb.] Carrière), a major commercial species in South Korea. To develop these models, models were fitted together for the xylem volume utilization rate and merchantable log utility rate to the total stem volume. Data on the logs bucked by cut-to-length usage in the forestry field were used for modeling, and the tree diameter at breast height (DBH) and small-end diameter of the last log were used as major predictor variables. Considering the difference in the bucking rate between all logs and solely long-length logs, the models for merchantable log utility rate were classified into two types: short- and long-length logs as well as only long-length logs. Consequently, the models were significantly developed, and the predicted values showed high accuracy within the range of observed values. The tables for bucking rate by cut-to-length log usage were finally provided by applying the models of the xylem volume utilization rate and merchantable log utility rate. Because the bucking rate for all logs and long-length logs can be easily calculated with the easy-to-use DBH and the required small-end diameter of the last log, the developed models are highly expected to be applicable for predicting the timber assortment using the cut-to-length log usage.

• Ecology and Resilient Infrastructure
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• v.11 no.3
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• pp.100-109
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• 2024

There are various methods in surface image velocimetry that can measure the flow velocity of a river surface using footage of a river surface. Among them, spatio-temporal image velocimetry (STIV) is widely used. This paper analyzed advantages and disadvantages of two STIV methods developed by the author, correlation-based STIV (C-STIV) and FFT-based STIV (F-STIV). This study also proposed a new method, hybrid STIV (H-STIV), that could supplement the advantages and disadvantages of the two existing methods by combining them. For the analyses, 20 cases of artificial spatio-temporal images, having image displacement ranging from 0.1 px/fr to 19.0 px/fr, were prepared. As a result, F-STIV was accurate with footage containing small image displacements and C-STIV was more accurate with footage containing large image displacements. For images with medium displacement, the two methods showed similar accuracies. Based on this result, H-STIV was proposed to adopt the result of F-STIV in displacements smaller than 2.0 px/fr (image strip slope 63.4°) and the result of C-STIV in larger displacements. As a result of applying the proposed method to argumentation, it was confirmed that H-STIV could calculate the flow velocity efficiently according to the situation.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.3
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• pp.228-235
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• 2024

Using transcranial doppler ultrasonography (TCD) to measure the presence or absence of abnormalities in patent foramen ovale (PFO) is more effective than transesophageal echocardiography (TEE) because it is simple, inexpensive, and non-invasive. Thus, it can be a good alternative test in cases where it is difficult to perform TEE or in groups at a high risk of complications. Therefore, in this study, we sought to assist in arriving at a diagnosis by suggesting an appropriate method through the comparison of empirical results according to the presence or absence of blood use and varying patient posture. The results were compared depending on the patient's posture and whether blood was used. Patients in whom both middle cerebral arteries were observed were targeted. In cases where the temporal window was defective, it was replaced with basilar artery and compared. There were higher positivity rate and accuracy for sitting position using valsalva maneuver (VM) than for Resting and supine position using VM. Therefore, if it is possible to perform a sitting position using VM with a mixture of blood, it would be a good idea to perform it.

• Convergence Security Journal
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• v.21 no.4
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• pp.109-115
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• 2021

Currently, with the development of 5G and IoT technology, it is being used in connection with the things used in real life through a network. However, attempts to use networked computers for malicious purposes are increasing, and attacks using malicious codes that infringe the confidentiality and integrity of user information are becoming more intelligent. As a countermeasure to this, research is being conducted on a method of detecting malicious packets using a security control system and AI technology, supervised learning. The cyber security control system is being operated inefficiently in terms of manpower and cost. In addition, in the era of the COVID-19 pandemic, remote work has increased, making it difficult to respond immediately. In addition, malicious code detection using the existing AI technology, supervised learning, does not detect variant malicious code, and has an inaccurate malicious code detection rate depending on the quantity and quality of data. Therefore, in this study, by converging malicious packet detection technologies through various machine learning and deep learning models, the accuracy of malicious packet detection is increased, the false positive rate and the false positive rate are reduced, and a new type of malicious packet can be efficiently detected when intrusion. We propose a malicious packet detection technology.

• Applied Chemistry for Engineering
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• v.35 no.5
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• pp.423-428
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• 2024

Microneedles with micron-sized needle arrays are an emerging technology for the transdermal administration of active pharmaceutical ingredients with minimally invasive pain. Over the past decade, although various additive manufacturing technologies have been employed for precise fabrication of microneedles, these methods are often limited by material compatibility and bioavailability, in addition to being time-consuming and costly. In here, we compare the resolution of Polyjet and DLP-SLA 3D printing methods for the precise fabrication of biodegradable PCLDA/PEGDA microneedles. To enhance the structural accuracy of the microneedles from both printing methods, we evaluate the 3D printing conditions, including 3D printing angle and needle height and diameter. Molds for microneedles are fabricated using optimized 3D printing methods, and subsequent replica molding processes are employed to fabricate the polymeric microneedles with sharp need tips. Finally, we use photocurable PCLDA and PEGDA for biodegradable and biocompatible microneedles, and their mechanical properties as PCLDA concentrations are analyzed to assess the strength required for skin insertion. This study has demonstrated the efficient and low-cost fabrication of high-resolution microneedles for transdermal drug delivery.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1295-1295
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• 2024

As extreme weather events such as heavy snowfall and typhoon become more frequent, climate change significantly impacts across various worldwide industries. With demands for dealing with this phenomenon, continuous achievements in safety diagnosis have been announced for large structures. Conversely, in agricultural infrastructures having lower risk to human life, there is lack of established safety diagnosis methods. However, considering expansion of high-value smart farm, the importance of plastic greenhouse cannot be overlooked. Therefore, this study aimed to develop on-site diagnosis technique for structural safety of steel structure greenhouse. To build an analysis model, we generated point cloud data of on-site greenhouse using a camera with LiDAR sensor. Subsequently, we extracted points corresponding to pipes using a pre-trained semantic segmentation model, achieving a pipe segmentation accuracy of 78.1%. These points were then converted into 3D frame model, with a location coordinate error of 5.4 cm for nine reference points, as measured by an on-site survey. In FEM structural analysis, nonlinearity of pipe connection was reflected. The loads were determined based on expected wind speed and snow depth in Korea. The structural safety of on-site model was diagnosed more vulnerable with 10.3% higher maximum axial stress, compared with standard model. Through this research, we expect the quantitative safety diagnosis of predicting greenhouse collapse risk. In addition, this technique will enable localized reinforcement strategies within the structure.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.241-250
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• 1997

The study was conducted to make a map for selecting righteous tree species for each site by digital terrain analysis. We set an algorithmic value for each tree species' characteristics with distribution pattern analysis, and the soil types were digitized from data indicated on soil map. Mean altitude, slope, aspect and micro-topography were estimated from the digital map for each block which had been calculated by regression equations with altitude. The results obtained from the study could be summarized as follows 1. We could develope a method to select righteous tree species for a given site with concern of soil, forest condition and topographic factors on Muju-Gun in Chonbuk province(2,500ha) by the terrain analysis and multi-variate digital map with a personal computer. 2. The brown forest soils were major soil types for the study area, and 29 tree species were occurred with Pinus densiflora as a dominant species. The differences in site condition and soil properties resulted in site quality differences for each tree species. 3. We tried to figure out the accuracy of a basic program(DTM.BAS) enterprised for this study with comparing the mean altitude and aspect calculated from the topographic terrain analysis map and those from surveyed data. The differences between the values were less than 5% which could be accepted as a statistically allowable value for altitude, as well as the values for aspect showed no differences between both the mean altitude and aspect. The result may indicate that the program can be used further in efficiency. 4. From the righteous-site selection map, the 2nd group(R, $B_1$) took the largest area with 46% followed by non-forest area (L) with 23%, the 5th group with 7% and the 4th group with 5%, respectively. The other groups occupied less than 6%. 5. We suggested four types of management tools by silvicultural tree species with considering soil type and topographic conditions.

• The Journal of Korean Academy of Sensory Integration
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• v.13 no.1
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• pp.13-22
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• 2015

Objective : The aim of this study is to verify validity of Long Form Assessment, which is an Interactive Metronome $measure^{(R)}$(LFA-IM), as a measurement of praxis of children. Methods : The study was implemented from March 2015 to July 2015. Twenty-five children with Attention Deficit Hyperactivity Disorder (ADHD) and those without ADHD (age of 6~11) were selected from a local university hospital and community in Gyeoung-Nam province and Busan for this study. In order to examine discriminative validity of LFA-IM, Bruininks-Oseretsky Test of Motor Proficiency, second edition (BOT-2) was used to compare the difference of results with LFA-IM for both children with- and without ADHD. For concurrent validity, correlation between LFA-IM and BOT-2 was investigated using spearman correlation coefficients. Results : For the comparison between children with ADHD and children without ADHD, there were significant differences in the total scores of LFA-IM (p<.05). Regarding the concurrent validity, there was a strong negative correlation between the total scores of LFA-IM and BOT-2 (p<.05). In addition, there was high correlation between LFA-IM and BOT-2 for the area of hand control (rs=-.532), and high negative correlation for the area of fine-motor accuracy (rs=-.447), hand dexterity (rs=-.532), and balance control (rs=-.623) (p<.05). Conclusion : This study identified validities of LFA-IM as an assessment of praxis of children. The results showed that it is appropriate to evaluate praxis of children with the total score of LFA-IM and, thus, it is believed that LFA-IM has a potential clinical utility. However, there should be more researches with large number of subjects.

• Journal of Environmental Impact Assessment
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• v.27 no.2
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• pp.181-193
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• 2018

The present study was conducted to analyze the quality of the habitats of Abies koreana WILS. by using the InVEST model based on the analytic hierarchy process (AHP) technique and to evaluate the economic value by estimating the carbon fixation. Abies koreana WILS., an original biological species of South Korea, may be an essential element in establishing the national biological sovereignty in the future. The subjects of the present study were the national parks in Mt. Halla, Mt. Jiri, and Mt. Sobaek, which are the habitats of Abies koreana WILS. As suggested by previous studies as a limitation of the InVEST model, the utilization of the data from relevant international publications as the input data, due to the lack of the domestic input data, may decrease the accuracy of the modeling. Therefore, the AHP technique was applied for the input data. The modeling was performed with reference to the years of 1980, 1990, and 2000 for the scenario analysis. The result of the modeling showed that the habitat quality was changed most in the national park in Mt. Halla, as the habitat quality score was decreased from 0.96 in 1980 to 0.97 in 1990 and 0.94 in 2000. In the national part of Mt. Sobeak, the habitat quality was changed most in the sub-alpine zone, as the habitat quality score was decreased from 0.98 in 1980 and 0.98 in 1990 to 0.97 in 2000. The habitat quality was best conserved in the national part in Mt. Jiri, as the habitat quality score was 0.98 in 1980, 0.99 in 1990, and 0.99 in 2000. The estimated economic loss by the change of the habitat quality was 19,280,000 USD for Mt. Halla and 8,030,000 USD for Mt. Sobeak. In the present study, the habitat quality of the Abies koreana WILS, the original species of South Korea, was evaluated and the economic value of the ecological services provided by the habitats was estimated quantitatively. The result showed that the ecosystem service model may be used to qualitatively analyze the quality of a habitat located in a specific region and to estimate the economic value quantitatively. The objective evaluation of ecosystem services demonstrated in the present study may be applied to promote sustainable utilization of natural resources and conservation of the ecosystem by predicting the changes that may be caused by external factors including the development of preservation areas.