• Journal of Korea Water Resources Association
• /
• v.39 no.2 s.163
• /
• pp.99-108
• /
• 2006

To describe the behavior of suspended-sediment particles in turbulent open-channel flows, the advection-diffusion equation or its simplified form has been used. Though this equation was derived upon several assumptions, only a few studies tried to evaluate the limit of the assumptions. The reason is that it is very difficult to measure turbulence in open-channel flows and to discriminate the velocities of water and sediment particles. The present study aims to measure the velocity profiles of water and sediment particles in open-channel flows by using PTV (Particle Tracking Velocimetry), a kind of PIV (Particle Image Velocimetry). The measured results showed that sediment particles moved slower than water tracers did in the outer region. In the present study, the amount of velocity-lag reached about $5\%$ of the mom flow velocity and the position of the maximum velocity-lag was $g/h\approx0.05\;(g^{+}=30\~50)$ The main cause of the velocity-lag of sediment particles seems that the sediment particles have larger density than water has. On the other hand, in the viscous sublayer, sediment particle has a larger velocity than water tracers. The reason of the inversion of velocity-lag may be due to the no-sleep condition of water at the solid boundaries.

• Journal of Korea Water Resources Association
• /
• v.48 no.2
• /
• pp.79-90
• /
• 2015

In this study, the water quality parameters of Geum-river were estimated using Landsat 8 satellite image data which had launched in March 2013. The goal of this research is to predict HAB and to monitor spatial pattern of total nitrogen (TN) and total phosphorus (TP) because both TN and TP are the dominant factors of the growth of harmful algal blooms (HABs). To investigate the relationship between satellite band reflectance and in situ measurement value, Pearson' correlation coefficient analysis was used. The band2, 3, 4 and 5 reflectance values among 11 bands of Landsat 8 were used which was highly associated with detecting TN and TP. The 20 in situ data set with satellite's overpass time were identified. TN showed positive relation with band 2 (0.48), band3 (0.62), band4 (0.57) at a significance level of p<0.05. TP also showed high correlation for band2 (0.59), band3 (0.59), band4 (0.58) at a significance level of p<0.01. The optimal regression equation models were constructed for TN and TP based on multiple regression equations. The estimated concentration based on derived regression equations of TN and TP were compared with in situ measurement data. Finally, the spatial pattern of the two parameters was able be monitored through mapping on November 12, 2013 and April 21, 2014.

• Journal of Life Science
• /
• v.20 no.7
• /
• pp.969-976
• /
• 2010

In vivo studies of KR-31125 (2-butyl-5-dimethoxymethyl-6-phenyl-7-methyl-3-[[2'-(1H-tetrazol-5-yl) biphenyl-4-yl]methyl]-3H-imidazo[4,5-b]pyridine) were performed in pithed rats, conscious angiotensin II (AII) challenged normotensive rats, renal hypertensive rats (RHRs) and furosemide-treated beagle dogs. KR-31125 induced a non-parallel right shift in the dose-pressor response curve to AII ($ID_{50}$: 0.095 mg/kg) with a dose-dependent reduction in the maximum responses in pithed rats. Compared to losartan, this antagonistic effect was about 18 times more potent, presenting competitive antagonism. Other agonists such as norepinephrine and vasopressin did not alter the responses induced by KR-31125. Orally administered KR-31125 had no agonistic effect and dose-dependently inhibited the pressor response to AII with a slightly weaker potency ($ID_{50}$: 0.25 and 0.47 mg/kg, respectively) in the AII-challenged normotensive rat model, but with a more rapid onset of action than losartan (time to $E_{max}$: 30 min for KR-31125 and 6 hr for losartan). KR-31125 produced a dose-dependent antihypertensive effect with a higher potency than losartan in RHRs, and these effects were confirmed in furosemide-treated dogs where they presented a dose-dependent and long-lasting (>8 hr) antihypertensive effect with a rapid onset of action (time to $E_{max}$: 2-4 hr), as well as a 20-fold greater potency than losartan. These results suggest that KR-31125 is a potent, orally active $AT_1$ receptor antagonist that can be applied to the development of new diagnostic and research tools as an added exploratory potential of $AT_1$ receptor antagonist.

• Journal of Navigation and Port Research
• /
• v.38 no.5
• /
• pp.437-442
• /
• 2014

Ocean Literacy is an understanding of the ocean's influence on you and your influence on the ocean. This research developed the 7 ocean education model courses using ocean literacy based on the analysis of ocean education programs which executed 23 agencies in Busan. These model courses are combined in the type of indoor theory, indoor experience, field study and field experience. Also, this makes the guide map for ocean education in a 76cm*56cm size to distinguish and choose the course easily. This map is the format combined in geological location and tourist attraction spots in Busan, includes education centers, contents, lead time and so on, and it is possible for educatees to handle their preference and seasonality elastically. This map including ocean education model course is a milestone to activate ocean education, and is helpful to reach the goal of ocean education and to lead ocean professionals. In addition, this research presents the development of teaching materials, training aids to complement the weakness of indoor education, the development of cyber education through making video contents as the activation measures of ocean education.

• Smart Media Journal
• /
• v.5 no.2
• /
• pp.33-41
• /
• 2016

FPS Games are usually centered on a combat game play where the player plays through a first-person perspective as the in-game character, in order to strike the opponent in accordance with each level's objective. In such type of game play, the decision making that leads the player to take certain actions is carried out based on the player's visual cognitive information, and information collected both directly/indirectly via previous game play experiences. Particularly in the case of a FPS game where the mutual interaction between the player and each game level is the key, an analysis of a FPS game player's visual cognitive information can provide intelligence which can help design or adjust structures of a game level. For this thesis, a sample group has been collected and divided into a novice group and an expert group based on their level of experience with FPS games. Then, using eye-tracking equipments, the point of gaze of players in each group were recorded whilst they were playing levels of a well-known FPS title. The point of gaze in the moment the player starts to take actions -right before/after the start of a combat- was recorded in 500 play videos, and as a result each group's intrinsic pattern of gaze could be identified. Through these results, the author plans to develop a methodology that can enhance the difficulty setting and the playability of FPS game levels.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.13 no.1
• /
• pp.35-41
• /
• 2020

Fast Fourier transform (FFT) processors have been widely used in various application such as communications, image, and biomedical signal processing. Especially, high-performance and low-power FFT processing is indispensable in OFDM-based communication systems. This paper presents a novel radix-26 FFT algorithm with low computational complexity and high hardware efficiency. Applying a 7-dimensional index mapping, the twiddle factor is decomposed and then radix-26 FFT algorithm is derived. The proposed algorithm has a simple twiddle factor sequence and a small number of complex multiplications, which can reduce the memory size for storing the twiddle factor. When the coefficient of twiddle factor is small, complex constant multipliers can be used efficiently instead of complex multipliers. Complex constant multipliers can be designed more efficiently using canonic signed digit (CSD) and common subexpression elimination (CSE) algorithm. An efficient complex constant multiplier design method for the twiddle factor multiplication used in the proposed radix-26 algorithm is proposed applying CSD and CSE algorithm. To evaluate performance of the previous and the proposed methods, 256-point single-path delay feedback (SDF) FFT is designed and synthesized into FPGA. The proposed algorithm uses about 10% less hardware than the previous algorithm.

• Journal of radiological science and technology
• /
• v.28 no.1
• /
• pp.55-65
• /
• 2005

Research of actual condition of working conditions in the small and clinics, in the Seoul metropolitan city and Kyeonggido province. With the health care environmental change such as a rapid increase of the elderly people, rapid increase of health promotion needs, it is necessary to analyse and identity of the actual condition of working conditions for present and new radiological technologist. Research of general characteristics for the present radiological technologist. To research of the status employment, business scope, pay, working conditions, radiation safety management, equipment, and category association. Defining the problems of related working conditions, radiation safety management for the comprehensive methods to promote the rights the radiological technologist. A proposal for establishment legislature and system of the actual condition in the hospital for radiological technologist. Estimation for the demand and supply numbers of present radiological technologist and improvement of employment relations. Improved and refined scope business and duty regulation related to radiological technologist. Application for the establishment and development of promotion rights to utilize as basic data in a legislative and system frame of reference to implement the radiological technologist.

• Korean Journal of Soil Science and Fertilizer
• /
• v.31 no.4
• /
• pp.315-323
• /
• 1998

Soil aggregate distribution and its relation to wind erosion were examined for the surface soil of the experimental plots for grasses in the New Incheon International Airport, of which soil was reclaimed with sea sands in the Youngjong Island. The soil aggregate with the size between 0.10 and 0.84mm was 74 percents. The 6 percents of the soil aggregates were non-erodible. With this aggregate distribution the wind erodiblity of the soil, I. was $380Mg\;ha^{-1}\;yr^{-1}$ with I value and climatic factor calculated for the dry period from November to May, $45.2Mg\;ha^{-1}\;yr^{-1}$ of the surface soil were estimated to be eroded. The erodible particles with 0.37mm diameter could fly to 17.8, 29.9 and 49.8 meters by saltation at wind speed of 7, 9 and $15m\;s^{-1}$, respectively. The wind erosion could be reduced by increasing vegetation coverage and applying hydrophyllic soil conditioner.

• Journal of Life Science
• /
• v.7 no.4
• /
• pp.308-308
• /
• 1997

Role of plant hormones on the leaf senescence of Phaseolus vulgaris were investigated by measuring the disassembly of chlorophyll-protein complexes in detached leaves treated with NAA, GA$_{3}$ , or BA. The loss of chlorophyll that was characteristic of leaf senescence induced disassembly of chlorophyll-protein complexed. During dark-induced senescence, PSI complex was rapidly degraded after the early stage, whereas RC-Core3 was slightly increased until the middle stage and slowly decreased thereafter. And gradual degradation of trimeric LCHII progressed after the late stage of senescence. Exogenous application of NAA and GA$_{3}$ had little or no effect in protecting disassembly of chlorophyll-protein complexes during leaf senescence compared to control. However exogenous BA application strongly leaves. In the simultaneous treatment of plant hormones and light, BA application under illumination of light was most effective in the stability of chlorophyll-protein complexes, particularly PSI, LHCII, RC-Core2, RC-Core3 and SC-1. these results suggest, therefore, that simultaneous application of BA and light induced synergistic effect on the stability off chlorophyll-protein complexes during leaf senescence.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.10
• /
• pp.303-308
• /
• 2019

Non-traumatic acute myelopathy caused by cervical disc herniation is rare. To date, no case has been reported to be caused by extrusion cervical disc herniation, unrelated to patient posture during surgery. Here, we report the case of a 65-year-old male patient with cervical myelopathy who underwent subsequent arthroscopic rotator cuff surgery under general anesthesia; non-cervical spine surgery. Ed. Notes: I am unable to understand the insertion of the highlighted phrase. Please delete if not required, or revise the sentence appropriately. Patient showed acute postoperative tetraplegia in spite of optimal anesthetic management. He showed no limitation of neck movement at pre-operative airway evaluation, and had no history of trauma to the cervical spine. During surgery, there had been no overextension or twisting of the neck, including at the time of anesthetic induction by tracheal intubation. However, cervical disc herniation causing spinal canal cord compression was detected in the postoperative magnetic resonance imaging, which probably resulted in tetraplegia of the patient. Motor and sensory functions were recovered after 21 days of conservative treatment, including steroid pulse intravenous therapy without any surgical intervention. In this report, the disease is described after reviewing other reported cases; furthermore, we also discuss the pathophysiology of the disease. Based on our report, we propose that under general anesthesia, clinicians should pay attention to the possibility of pre-existing cervical disease, even in non-cervical spine surgeries of geriatric patients.