• Asian Journal of Turfgrass Science
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• 제20권2호
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• pp.223-235
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• 2006

Soil testing laboratories unfamiliar with turfgrasses will often overestimate the plant's need for phosphorus and underestimate the need for potassium. This is partly due to differences in rooting between grasses and many garden plants and crops. The grasses are generally more efficient in extracting phosphorus from the soil, reducing their need for phosphorus fertilizer. The fact that crop yield is often the primary objective in field crop production, and is usually of little interest in turfgrass management, may affect soil test interpretation for potassium. Potassium levels above those required for maximum tissue yield of grasses may improve stress tolerance and turfgrasses will usually benefit from higher applications of this element. There are also diffrrences in soil testing philosophies. Some laboratories use the sufficiency level of available nutrients(SLAN) approach, whereas others prefer the basic cation saturation ratio(BCSR) approach. Some will use a combination of the two methods. The use of the BCSR theory easily lends itself to abuse and questionable fertilizer applications and products are sometimes recommended citing imbalances in cation ratios. The usefulness of the BCSR ratio theory of soil testing varies with soil texture and interpretations on tests performed on sand-based media are particularly a problem. Other soil testing problems occur when sand-based media used on sports fields and golf greens contain free calcium carbonate. The ammonium acetate extractant at pH 7.0 dissolves excessive amounts of calcium that can bias cation exchange capacity measurements and measurements of cation ratios. Adjusting the pH of the extractant to 8.1 can improve the accuracy of the testing procedure for calcareous media.

• Structural Engineering and Mechanics
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• 제57권1호
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• pp.1-20
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• 2016

On the basis of the geological conditions of high and steep mountainous slope on which an exit portal of an express railway tunnel with a bridge-tunnel combination is to be built, the composite structure of the exit portal with a bridge abutment of the bridge-tunnel combination is presented and the stability of the slope on which the express railway portal is to be built is analyzed using three dimensional (3D) numerical simulation in the paper. Comparison of the practicability for the reinforcement of slope with in-situ bored piles and diaphragm walls are performed so as to enhance the stability of the high and steep slope. The safety factor of the slope due to rockmass excavation both inside the exit portal and beneath the bridge abutment of the bridge-tunnel combination has been also derived using strength reduction technique. The obtained results show that post tunnel portal is a preferred structure to fit high and steep slope, and the surrounding rock around the exit portal of the tunnel on the high and steep mountainous slope remains stable when rockmass is excavated both from the inside of the exit portal and underneath the bridge abutment after the slope is reinforced with both bored piles and diaphragm walls. The stability of the high and steep slope is principally dominated by the shear stress state of the rockmass at the toe of the slope; the procedure of excavating rockmass in the foundation pit of the bridge abutment does not obviously affect the slope stability. In-situ bored piles are more effective in controlling the deformation of the abutment foundation pit in comparison with diaphragm walls and are used as a preferred retaining structure to uphold the stability of slope in respect of the lesser time, easier procedure and lower cost in the construction of the exit portal with bridge-tunnel combination on the high and steep mountainous slope. The results obtained from the numerical analysis in the paper can be used to guide the structural design and construction of express railway tunnel portal with bridge-tunnel combination on high and abrupt mountainous slope under similar situations.

• Journal of the Society of Cosmetic Scientists of Korea
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• 제41권4호
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• pp.413-420
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• 2015

The skin is one of the largest organs in our body and participates in many of the human organism's physiological and pathological events. Skin function were known for self-maintenance and self-repair, mechanical and chemical stress protection, protection against UV and environmental pathogenic micro-organisms, production of vitamin D, and social and psychological function through the physical aspect. The aim of this study was to evaluate the variation of biophysical parameters and to find relation with skin biomarkers in different anatomical site and age in Korean women. About 70 healthy volunteers in age range 20 to 49 were participated in this test. Test areas were the forearms and the cheek. Investigation to determine biophysical parameters on human skin, was carried out using various non-invasive methods. For analysis to skin biomarkers, we studied to examine various biomarkers for the quantitative determination of cortisol, fibronectin, keratin-1, 10, and 11, involucrin, and keratin-6 in human face and forearm. And we measured to skin biophysical parameters for skin anatomical site and age difference with non-invasive methods. As results of measuring site, some parameters were have following significant difference, stratum corneum hydration, trans epidermal water loss and skin color (L and a value). As results of age difference, skin colors were had only significant difference with age. For cortisol, keratin-6, fibronectin, keratin-1, 10, 11 contents, there were no significant difference in age and site. However, involucrin level in the cheeks were the highest for age group 30 ~ 39 compared to other age groups. These results suggest that in individual skin condition may explain detailed skin state variation.

• Korean Journal of Clinical Laboratory Science
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• 제53권4호
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• pp.285-295
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• 2021

Sleep plays an important role in maintaining overall human health. There is increasing interest regarding the impact of sleep related disorders on metabolic diseases. Obstructive sleep apnea (OSA) is a common health problem, and in the last decade, the emergence of increasing obesity rates has further led to a remarkable increase in the prevalence of OSA, along with more prominent metabolic diseases. Obesity is the strongest risk factor for OSA. However, OSA is also known to cause obesity, suggesting an interaction between OSA and obesity. Although the underlying mechanisms leading to OSA-induced metabolic diseases are probably multi-factorial and are yet to be fully elucidated, the activation of inflammation and oxidative stress and the dysregulation of appetite-regulating hormones have emerged as important pathophysiological components of metabolic dysfunction and obesity observed in patients with OSA. Here, we will review the current state of research regarding the association of OSA with metabolic diseases and the possible pathophysiological mechanisms by which OSA could lead to such diseases. This will enhance our understanding of the potential interactions between OSA and obesity and between OSA and metabolic dysfunction.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제22권4호
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• pp.473-482
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• 2021

The introduction of automated flight systems has greatly improved aviation safety, but aircraft pilots continue to face new challenges. The pilot's stress from an aeronautical perspective can be distinguished by the 'Startle and Surprise' responses. 'Startle' is a short, strong physiological response to sudden or threatening stimuli such as unexpected gunfire. 'Surprise' is a cognitive-emotional response to an event that goes beyond one's expectations. In Martin et al.'s (2012) Startle Effect Experiment, the pilot identified physiological responses in the 'Startle' state, including delayed response and increased heart rate. In the Rahim (2020) Startle/Surprise experiment, the pilot's breathing rate and pulse rate did not change due to pre-planned emergency training. On the other hand, it was confirmed that the pilot's respiratory and heart rate were greatly increased due to the complicated aircraft and unplanned emergencies. Based on the results of these experiments, domestic pilots need to be trained to handle non-technical and various unexpected emergencies that could arise in an aircraft, rather than be just put through courses for enhancing technical capabilities or simple repetitive training as required by aviation law.

• Journal of Korean Tunnelling and Underground Space Association
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• 제20권6호
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• pp.1003-1022
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• 2018

In the current work, a series of three-dimensional finite element analyses were carried out to understand the behaviour of a pre-existing single pile to the changes of the tunnel face pressures when a shield TBM tunnel passes underneath the pile. The numerical modelling analysed the results by considering various face pressures (25~100% of the in-situ horizontal stress prior to tunnelling at the tunnel springline). In the numerical modelling, several key issues, such as the pile settlements, the axial pile forces, the shear stresses have been thoroughly analysed for different face pressures. The head settlements of the pile with the maximum face pressure decreased by about 44% compared to corresponding settlement with the minimum face pressure. Furthermore, the maximum axial force of the pile developed with the minimum face pressure. The tunnelling-induced axial pile force at the minimum face pressure was found to be about 21% larger than that with the maximum face pressure. It has been found that the ground settlements and the pile settlements are heavily affected by the face pressures. In addition, the influence of the piles and the ground was analysed by considering characteristics of the soil deformations. Also, the apparent safety factor of the piles are substantially reduced for all the analyses conducted in the current simulation, resulting in severe effects on the adjacent piles. Therefore, the behaviour of the piles, according to change the face pressures, has been extensively examined and analysed by considering the key features in great details.

• The Korean Journal of Archival Studies
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• 제27호
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• pp.3-33
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• 2011

Despite the Public Records Management Act in effect for more than 10 years and the various achievements of 'Records management Innovation' made by the former government, records management in Korea still remains unsatisfactory in many fields. Especially one of the main concerns is about the records centers in the public offices failed to work efficiently. There remains lots of so-called ancient regime elements in the records center system, which causes the lack of stability. Divisions of general affairs in the public offices had played main role in records management for more than 50 years since the establishment of the government, and their role was limited to take over some records created and to manage the poor stack room. According to the Public Records Management Act revised in 2007, data center was renamed to records center and it was obliged to place records center under the office of planning management or the office of administration. But records centers have been nevertheless operated at a very formal level in most public offices. It is the real state of affairs that professional records management system interconnecting records office, records center and archives is not achieved. Why is it? This article is an answer to this question. This article attempt to find out on the inner causes such as structure of records center, records management profession, records management methodology, and above all historical background. In addition, it put stress on the necessity of definite separation between records office and records center and assurance of independent operation of records center for the normalization of the records management system. Improvement of methodology including records management process is also of great importance. And the standardization of records management business of the records center is suggested as one of the main tasks on the basis of the accumulation of 'best practices of records management' in the cooperation with the records management community.

• The Korean Journal of Archival Studies
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• 제56호
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• pp.147-182
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• 2018

Intangible cultural heritage is formless. It's of importance to preserve heritage in line with society drastically being transformed. It's passed down by human being. It is, on the other hand, impossible to preserve intangible cultural heritage solely based on memory, for it's changed in succession. Thus, it be archived to pass down. This study investigated on the state of affair related with Intangible cultural heritage documentations, examined the shortages thereupon. Furthermore, Training center should be in charge of documentation for a solution. This will provide an opportunity to overcome the limitations attributed to the top-down documentation system by central administrative organ, to open up the possibility of viewpoint of different successors, organizations. In addition to that, Intangible cultural heritage documents should be of different aspects of community history. Features of Intangible cultural heritages, which are convergent to the Regionality, tendency of variation, transmission, can be magnified when documentating. Finally, Training center is going to play a major role being vitalised. The record management of intangible cultural heritage, institutions and policies about Intangible cultural heritage have been highly complicated since National Intangible Heritage Center opened and the law on Intangible cultural heritage enacted with its recognition attracted. Therewith this study wishes to see a cornerstone of records on intangible cultural heritage by laying stress on training center in which educations and pass-down of intangible cultural heritage are lively achieved.

• Journal of the Computational Structural Engineering Institute of Korea
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• 제32권2호
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• pp.87-92
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• 2019

In this paper, we have verified a low-voltage EM(elasto-magnetic) sensing technique for tensile force management of PSC(prestressed concrete) internal tendon in order to apply the technique to actual construction sites where stable power supply is difficult. From observation of past domestic and overseas PSC structural accident cases, it was found that PS tension is very important to maintain structural stability. In this paper, we have tried to measure the tensile force from a magnetic hysteresis curve through EM sensors according to voltage value by using relation between magnetostriction and stress of ferromagnetic material based on elastic-magnetic theory. For this purpose, EM sensor of double cylindrical coil type was fabricated and tensile force test equipment for PS tendon using hydraulic tensioning device was constructed. The experiment was conducted to confirm relationship between changes of permeability and tensile force from the measurement results of the maximum / minimum voltage amount. The change of magnetic hysteresis curve with magnitude of tensile force was also measured by reducing amount of voltage step by step. As a result, the slope of estimation equation in accordance with magnitude of magnetic field decreases with the voltage reduction. But it was confirmed a similar pattern of change of magnetic permeability for the magnetic hysteresis loop. So, in this study, it is considered that it is possible to manage the tensions of PSC internal tendon using EM sensing technique in low-voltage state.

• Fisheries and Aquatic Sciences
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• 제24권1호
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• pp.19-31
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• 2021

Seaweeds are a potential source of minerals, essential amino acids, fatty acids, proteins, and various bioactive compounds such as antioxidants. The higher water content of seaweeds reduces the shelf life and this requires the appropriate drying method. The drying conditions play a major role in the conservation of nutrient composition in dried seaweeds. In recent years, the seaweed industry has used many different drying methods with advantages and limitations. Hybrid hot-water Goodle dryer (HHGD) which is a special dryer mixed with hot-water and a Korean traditional heating system (Goodlejang) might be a solution to avoid these limitations. The present study evaluated the effect of drying conditions in HHGD on nutrient composition and bioactivities of brown seaweeds. Moreover, freeze-dryer (FD) and HHGD were employed in this study to compare the dried outputs obtained from four brown seaweed species. The present study aims to evaluate the effect of the hybrid hot-water Goodle drying method (HHGDM) on the nutritional composition and antioxidant activity of dried seaweeds. AOAC standard methods were used to analyze the proximate composition of dried samples and their 70% ethanol extract. The intracellular and extracellular antioxidant activities were evaluated using Vero cells and electron spin resonance (ESR) spectrometer respectively. High performance liquid chromatography, apoptotic body formation, and in-vivo experiments were used for further confirmation of the quality of dried output. The proximate composition results obtained from drying in HHGD and FD did not exhibit any significant difference. Moreover, the seaweed extracts from the dried seaweeds by HHGD and FD dryings were also not different and both significantly down-regulated in-vivo and in-vitro oxidative stress. Furthermore, the high performance liquid chromatography results revealed that the two dryers did not make the major peaks different in the chromatograms. Freeze-drying method (FDM) provides elevated quality for dried output, but there are limitations such as high cost and low capacity. The results from a novel HHGD did not provide any significant difference with the results in FD and expressed a potential to avoid the limitations in FD. Overall, these findings solidified the applicability of HHGD over FD.