• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.4
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• pp.519-534
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• 2019

Mechanized tunneling methods, including shield TBM, have been increasingly used for tunnel construction because of their relatively low vibration and noise levels as well as low risk of rock-falling accidents. In the excavation using the shield TBM, it is important to design penetration rate appropriately. In present study, both subsurface investigation data and shield TBM excavation data, produced for and during ${\bigcirc}{\bigcirc}{\sim}{\bigcirc}{\bigcirc}$ high-speed railway construction, were analyzed and used to compare with shield TBM penetration rates calculated using existing penetrating rate prediction models proposed by several foreign researchers. The correlation between thrust force per disk cutter and uniaxial compressive strength was also examined and, based on the correlation analysis, a simple prediction model for penetration rate was derived. The prediction results using the existing prediction models showed approximately error rates of 50~500%, whereas the results from the simple model proposed from this study showed an error rate of 15% in average. It may be said, therefore, that the proposed model has higher applicability for shield TBM construction in similar ground conditions.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1302-1307
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• 2018

The crystallographic, electrical and magnetic behaviors of magnetite powder in the vicinity of its Verwey transition were investigated in this study. Magnetite was prepared by synthesizing a nanoparticle precursor and then annealing it at $800^{\circ}C$ for 1 h under a dynamic vacuum. Crystallographic and morphology analyses were done by using scanning electron microscope (SEM) and X-ray diffraction (XRD). The electrical and the magnetic properties were examined by using $M{\ddot{o}}ssbauer$ spectroscopy, vibrating sample magnetometer (VSM) and resistivity measurement. Both the magnetic moment and the resistivity showed discontinuous changes at the Verwey transition temperature ($T_V$). The temperature dependence of magnetic anisotropy constant showed a monotonic decrease with increasing temperature, with slight dip near $T_V$. $M{\ddot{o}}ssbauer$ spectra showed the superposition of two sextets, one from the tetrahedral (A) and the other from the octahedral (B) sites. The results revealed that identical charge states existed in the B site at temperatures both above and below $T_V$. A coordination crossover resulted in a transition from an inverse to a normal spinel at or close to $T_V$.

• 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.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.450-465
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• 2017

This study was conducted to characterize the amylose and protein contents of 4,948 rice landrace germplasm using the NIRS model developed in the previous study. The average amylose content of the germplasm was 20.39% and ranged between 3.97 and 37.13%. The amylose contents in the standard rice were 4.99, 18.63 and 20.55% in Sinseonchal, Chucheong and Goami, respectively. The average protein content was 8.17% and ranged from 5.20 to 17.45%. Protein contents in Sinseonchal, Chucheong and Goami were 6.824, 6.869 and 7.839%, respectively. A total of 62% germplasm were distributed between 20.06% and 27.02% in amylose content. Germplasm of 81.60% represented protein content of 6.78-9.75%. The distinguishable ranges of amylose contents according to origin were 16.58-20.06% in Korea, 20.06-23.25% in Japan, 23.25-27.02% in North Korea, and 27.02-37.13% in China. In the protein content, approximately 30% of Chinese resources ranged from 9.75 to 17.45%, whereas less than 10% were detected in other origin accessions. Fifty resources were selected with low and high amylose ranging from 3.97-6.66% and 30.41-37.13%, respectively. Similarly, fifty resources were selected with low and high protein ranging from 5.20-6.09% and 13.21-17.45%, respectively. Landraces with higher protein could be adapted to practical utilization of food sources.

• Journal of the Korean earth science society
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• v.21 no.5
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• pp.623-634
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• 2000

This study was conducted to analyze the patterns associated with the short-term variability of CO$_2$ concentrations over 24-h scale within and across the Korean Peninsula. In the course of our study, we compared the data sets obtained from Moo-Ahn (MAN) station located in the far western coastal area of Korea with those determined from major background observatory stations around the world from the periods of Aug. 1995 to Dec. 1997. The mean CO$_2$ concentration of the MAN area for the whole study periods, when computed using the daily mean values, was found out to be 374.5${\pm}$6.6 ppm (N=884); seasonal mean values were found out to be 378${\pm}$5.2 (spring: N=181), 372${\pm}$10.2 (summer: N =210), 372${\pm}$7.2 (fall: N=243), and 376${\pm}$5.4 ppm (winter: N=206). When the data from MAN was compared with those of major background stations, the effects of both daily and seasonal components appear to vary distinctively across different stations. Those effects are expected to reflect the mixed effects of various factors which include: seasonal pollution patterns, weather conditions, vegetation, and so forth. Based upon this comparative analysis, we suspect that the MAN area is under the strong influence of anthropogenic source processes relative to all the other stations under consideration. If that is not the case, the existence of enhanced CO$_2$ level may be rather ubiquitous phenomena in Korea. More detailed inspection of CO$_2$ behavior from various respects is strongly desired in the future.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.641-648
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• 2008

There has been great success for making transgenic animals using somatic cell nuclear transfer(SCNT) up to this time. However, the success rates of the production of live transgenic animals are still very low. The current research has been carried out for delineation of differentially expressed genes between SCNT and normal placenta in cattle. In the present observations, high expression has been observed for CTSZ, LOC509426 and ELF1 genes in normal placenta. On the other hand, TIMP2, PAG1B, PAG-21, LOC782894, SERPINB6 and mKIAA2025 protein were highly expressed in SCNT placenta. Five genes, which were highly expressed in SCNT placenta, have been further investigated using semi-quantitative real-time PCR. The results were similar to that we observed using ACP. In the future, all genes affecting the SCNT and normal placenta have to be discovered and their networks will be fully investigated. The genes were identified in this study would be great help for identifying differential gene expressions in SCNT placenta.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.191-200
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• 2017

Proper packaging design can meet both the environmental and economic aspects of packaging materials by reducing the use of packaging materials, waste generation, material costs, and logistics costs. Finite element analysis(FEM) is used as a useful tool in various fields such as structural analysis, heat transfer, fluid motion, and electromagnetic field, but its application in the field of packaging is still insufficient. Therefore, the application of FEM to the field of packaging can save the cost and time in the future research because it is possible to design the package by computer simulation, and it is possible to reduce the packaging waste and logistics cost through proper packaging design. Therefore, this study investigated the FEM papers published in Korea for the purpose of helping research design using FEM program in the field of packaging in the future. In this paper, we analyzed the 29 papers that were directly related to the analysis of FEM papers published in domestic journals from 1991 to 2017. As a result, we analyzed the research topic, FEM program, and analysis method using each paper, and presented the direction that can be applied in future packaging field. When the FEM is applied to the packaging field, it is possible to change the structure and reduce the thickness through the stress and vibration analysis applied to the packaging material, thereby reducing the cost by improving the mechanical strength and reducing the amount of the packaging material. Therefore, in the field of packaging research in the future, if the FEM is performed together, economical and reasonable packaging design will be possible.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.14 no.2
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• pp.135-141
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• 2014

Objectives: Fabry disease (FD) is a lysosomal storage disease caused by the inappropriate accumulation of globotriaosylceramide (Gb3) in tissues due to a deficiency in the enzyme ${\alpha}$-galactosidase A. Hypertrophic cardiomyopathy is one of the chronic complications of FD. We tried to evaluate the prevalence of Fabry disease in the Korean patients with left ventricular hypertrophy (LVH). Methods: A total of 257 patients with LVH were recruited and they were 172 males (mean 56 years, range 30-81 years) and 84 females (mean 66 years, range 45-85 years). Urinary Gb3 was used to screen FD by high performance liquid chromatography-tandem mass spectrometry. Confirmatory tests were done by alpha-galactosidaseA activity using fluorometric assay and by GLA mutation analysis using sequencing. Results: Four patients were screening positive by urinary Gb3 analysis (cutoff, 25 ug/mmol creatinine). But, one female patient was diagnosed with FD confirmed by enzyme analysis in leukocytes as well as by genetic analysis (1/257 patients, 0.4%). She showed 54.3 ug/mmoL creatinine of Gb3 and 15.5 nmole/hr/mg protein (reference range, $55.2{\pm}12.7nmole/hr/mg$ protein) of alphagalactosidase A activity. And she had a heterozygous GLA mutation of c.796G>A (p.D266N). Her daughter was found to be a carrier for FD confirmed by GLA mutation analysis. Asymptomatic carrier showed 25.5ug/mmol creatinine of Gb3 and 42.5 nmole/hr/mg protein (reference range, $55.2{\pm}12.7nmole/hr/mg$ protein) of alpha-galactosidase A activity. Conclusions: The prevalence of FD in Koran patients with LVH was detected as 0.4%. Although the prevalence seems to be low, screening studies are of great importance for detecting hidden cases as well as for identifying other effected family members.

• Journal of Climate Change Research
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• v.2 no.4
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• pp.237-251
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• 2011

This study presents a review on the recent climate change over the Korean peninsula, which has experienced a significant change due to the human-induced global warming more strongly than other regions. The recent measurement of carbon dioxide concentrations over the Korean peninsula shows a faster rise than the global average, and the increasing trend in surface temperature over this region is much larger than the global mean trend. Recent observational studies reporting the weakened cold extremes and intensified warm extremes over the region support consistently the increase of mean temperature. Surface vegetation greenness in spring has also progressed relatively more quickly. Summer precipitation over the Korean peninsula has increased by about 15% since 1990 compared to the previous period. This was mainly due to an increase in August. On the other hand, a slight decrease in the precipitation (about 5%) during Changma period (rainy season of the East Asian summer monsoon), was observed. The heavy rainfall amounts exhibit an increasing trend particularly since the late 1970s, and a consecutive dry-day has also increased primarily over the southern area. This indicates that the duration of precipitation events has shortened, while their intensity became stronger. During the past decades, there have been more stronger typhoons affecting the Korean peninsula with landing more preferentially over the southeastern area. Meanwhile, the urbanization effect is likely to contribute to the rapid warming, explaining about 28% of total temperature increase during the past 55 years. The impact of El Nino on seasonal climate over the Korean peninsula has been well established - winter [summer] temperatures was generally higher [lower] than normal, and summer rainfall tends to increase during El-Nino years. It is suggested that more frequent occurrence of the 'central-Pacific El-Nino' during recent decades may have induced warmer summer and fall over the Korean peninsula. In short, detection and attribution studies provided fundamental information that needed to construct more reliable projections of future climate changes, and therefore more comprehensive researches are required for better understanding of past climate variations.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1972.03a
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• pp.5-6
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• 1972

Noise and air pollution, which accompany the development of industry and the increase of population, contribute to the deterioration of urban environment. The air pollution level of Seoul has gradually increased and the city residents are suffering from a high pollution of noise. If no measures were taken against pollution, the amount of emission of pollutant into air would be 36.7 thousand tons per year per square kilometer in 1975, three times more than that of 1970, and it would be the same level as that of United States in 1968. The main sources of air pollution in Seoul are the exhaust has from vehicles and the combustion of bunker-C oil for heating purpose. Thus, it is urgent that an exhaust gas cleaner should be instaled to every car and the fuel substituted by less sulfur-contained-oil to prevent the pollution. Transportation noise (vehicular noise and train noise) is the main component of urban noise problem. The average noise level in downtown area is about 75㏈ with maximum of 85㏈ and the vehicular homing was checked 100㏈ up and down. Therefore, the reduction of the number of bus-stop the strict regulation of homing in downtown area and a better maintenance of car should be an effective measures against noise pollution in urban areas. Within the distance of 200 metres from railroad, the train noise exceeds the limit specified by the pollution control law in Korea. Especially, the level of noise and steam-whistle of train as measured by the ISO evaluation can adversely affect the community activities of residents. To prevent environmental destruction, many developed countries have taken more positive action against worsening pollution and such an action is now urgently required in this country.