• Title/Summary/Keyword: Floating Time

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A Study on the Application of Physical Soil Washing Technology at Lead-contaminated Shooting Range in a Closed Military Shooting Range Area (폐 공용화기사격장 내 납오염 사격장 군부지의 물리적 토양세척정화기술 적용성 연구)

  • Jung, Jaeyun;Jang, Yunyoung
    • Journal of Environmental Impact Assessment
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    • v.28 no.5
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    • pp.492-506
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    • 2019
  • Heavy metal contaminants in the shooting range are mostly present in a warhead circle or a metal fragment present as a particle, these fine metal particles are weathered for a long period of time is very likely that the surface is present as an oxide or carbon oxide. In particular, lead which is a representative contaminant in the shooting range soil, is present as more fine particles because it increases the softness and is stretched well. Therefore, by physical washing experiment, we conducted a degree analysis, concentration of heavy metals by cubic diameter, composition analysis of metallic substances, and assessment of applicability of gravity, magnetism and floating selection. The experimental results FESEM analysis and the measurement results lead to the micro-balance was confirmed thatthe weight goes outless than the soil ofthe same size in a thinly sliced and side-shaped structure according to the dull characteristics it was confirmed that the high specific gravity applicability. In addition, the remediation efficiency evaluation results using a hydrocyclone applied to this showed a cumulative remediation efficiency of 71%,twice 80%, 3 times 91%. On the other hand, magnetic sifting showed a low efficiency of 17%,floating selection -35mesh (0.5mm)target soil showed a relatively high efficiency to 39% -10mesh (2mm) efficiency was only 16%. The target treatment diameter of soil washing should be 2mm to 0.075mm, which is applied to the actual equipment by adding an additional input classification, which would require management as additional installation costs and processes are constructed. As a result, it is found that the soilremediation of shooting range can be separately according to the size of the warhead. The size is larger than the gravel diameter to most 5.56mm, so it is possible to select a specific gravity using a high gravity. However, the contaminants present in the metal fragments were found to be processed by separating using a hydrocyclone of the soil washing according to the weight is less than the soil of the same particle size in a thinly fragmented structure.

Modeling of Sensorineural Hearing Loss for the Evaluation of Digital Hearing Aid Algorithms (디지털 보청기 알고리즘 평가를 위한 감음신경성 난청의 모델링)

  • 김동욱;박영철
    • Journal of Biomedical Engineering Research
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    • v.19 no.1
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    • pp.59-68
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    • 1998
  • Digital hearing aids offer many advantages over conventional analog hearing aids. With the advent of high speed digital signal processing chips, new digital techniques have been introduced to digital hearing aids. In addition, the evaluation of new ideas in hearing aids is necessarily accompanied by intensive subject-based clinical tests which requires much time and cost. In this paper, we present an objective method to evaluate and predict the performance of hearing aid systems without the help of such subject-based tests. In the hearing impairment simulation(HIS) algorithm, a sensorineural hearing impairment medel is established from auditory test data of the impaired subject being simulated. Also, the nonlinear behavior of the loudness recruitment is defined using hearing loss functions generated from the measurements. To transform the natural input sound into the impaired one, a frequency sampling filter is designed. The filter is continuously refreshed with the level-dependent frequency response function provided by the impairment model. To assess the performance, the HIS algorithm was implemented in real-time using a floating-point DSP. Signals processed with the real-time system were presented to normal subjects and their auditory data modified by the system was measured. The sensorineural hearing impairment was simulated and tested. The threshold of hearing and the speech discrimination tests exhibited the efficiency of the system in its use for the hearing impairment simulation. Using the HIS system we evaluated three typical hearing aid algorithms.

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An Area-Efficient Time-Shared 10b DAC for AMOLED Column Driver IC Applications (AMOLED 컬럼 구동회로 응용을 위한 시분할 기법 기반의 면적 효율적인 10b DAC)

  • Kim, Won-Kang;An, Tai-Ji;Lee, Seung-Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.5
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    • pp.87-97
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    • 2016
  • This work proposes a time-shared 10b DAC based on a two-step resistor string to minimize the effective area of a DAC channel for driving each AMOLED display column. The proposed DAC shows a lower effective DAC area per unit column driver and a faster conversion speed than the conventional DACs by employing a time-shared DEMUX and a ROM-based two-step decoder of 6b and 4b in the first and second resistor string. In the second-stage 4b floating resistor string, a simple current source rather than a unity-gain buffer decreases the loading effect and chip area of a DAC channel and eliminates offset mismatch between channels caused by buffer amplifiers. The proposed 1-to-24 DEMUX enables a single DAC channel to drive 24 columns sequentially with a single-phase clock and a 5b binary counter. A 0.9pF sampling capacitor and a small-sized source follower in the input stage of each column-driving buffer amplifier decrease the effect due to channel charge injection and improve the output settling accuracy of the buffer amplifier while using the top-plate sampling scheme in the proposed DAC. The proposed DAC in a $0.18{\mu}m$ CMOS shows a signal settling time of 62.5ns during code transitions from '$000_{16}$' to '$3FF_{16}$'. The prototype DAC occupies a unit channel area of $0.058mm^2$ and an effective unit channel area of $0.002mm^2$ while consuming 6.08mW with analog and digital power supplies of 3.3V and 1.8V, respectively.

An Empirical Study on the Improvment of VTS in Korea (우리나라 선박교통제제도의 개선방안에 관한 실증연구 - 포항항을 중심으로 -)

  • 임을빈;문성혁
    • Journal of the Korean Institute of Navigation
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    • v.21 no.2
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    • pp.47-58
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    • 1997
  • The purpose of this study is to find out the impacts of VTS on the marine safety and users' opinion on the VTS which have been being operated in the port of Pohang for the last 3 years and is to suggest a guideline to the successful operation of VTS in the future. This study is based upon the questionnaire survey and the respondents include 236 masters/mates of merchant vessels who have visited the port of Pohang and 6 pilots who have been working in the port. From the questionnaire results, this study notes the following conclusions related to the VTS operations. (1) A few of the respondents (mainly foreigners) do not understand the entering procedure of the port and the fundamental concept of VTS. Accordingly, the more active VTS services have to be provided for the mariners. (2) It was found that themost dangerous factors in tehvicinity of the port were the floating materials, fishing nets, andillegal fishing activities inthe fairway. Therefore, the proper surveillance, stricter enforcement of Acts and the instructive education for the fishermen are required to avoid the risks. (3) A majority of the respondents agreed the VTS has contributed to the safety of vessel traffic, and they pointed out ' the assiatances in reduced visibililty conditions' is the most important task of VTS. The amount of 75.6% of the respondents answered that they have experienced the assistance from VTS more than 1 time since the system was established in the port of Pohang . Also 44.2% of the respondents considered they were able to avoid marine casualties such as collision, ramming or agrounding with the VTS assistances. (4) 49.2% of the respondents preferred the passive information services , while, 38.8% of them preferred the positive control advices in the case of encountering any potential risks. VTS iperators have to consider seriously when they provide the positive control advices of ship's course and speed. (5) A majority of the respondents confirmed that the prot and its approaches is suitable for the VTS coverge . To extend the service areas of the VTS and to improve radar detecting ability, the use of radar transponders are seen as the ideal method. (6) A minority of the respondents pointed out 'the improper orders or recommendatinos caused by the poor decision making' firstly, ' the language problem(sea-speaking in English)' secondly, as the deficiency of personal qualification. It seems, therefore, theat the personal efforts of the operators and systematic training programmes for them are necessary to solve the problems.

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Seed Germination and Effect of Water Depths on Seedling Establishment of Iron-coated Rice Seeds (벼 철분코팅종자의 발아 특성 및 담수깊이에 따른 초기입모 영향)

  • Kim, Sang-Yeol;Park, Sung-Tae;Seo, Jong-Ho;Hwang, Chung-Dong;Bae, Hyun-Kyung;Oh, Myung-Kyu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.62 no.1
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    • pp.9-15
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    • 2017
  • Germination characteristics, seedling emergence, and early seedling growth of iron-coated rice seeds, cultivars Daebo and Samdeokbyeo, under different water depths were compared with those of non-coated seeds (control) and the results evaluated to obtain basic information for establishing stable seedlings in direct water seeding. The total germination percentage of the two seed treatments was similar, but iron-coated seeds had slightly faster germination and shorter mean germination time than non-coated seeds. Water absorption rates of iron-coated seeds were lower than that of non-coated seeds during seed germination. The germination percentage of the two iron-coated rice seed cultivars showed a significant decline of 15-22% after one year of storage under natural conditions. The seedling emergence percentage and uniformity of the two rice cultivars were significantly higher in the iron-coated seeds at 1-13 cm water depths but the percentage of floating seedlings was lower in iron-coated seeds than in non-coated seeds. The iron-coated seeds had a high seedling emergence percentage of 91.3-93.3% at all flooding depths whereas the non-coated seeds had a significantly low seedling emergence percentage of 57.7-71.7% at a water depth of 13 cm. Moreover, the shoot dry weight and seedling health score of iron-coated seeds were significantly higher than those of non-coated seeds, while root dry weights were similar in iron-coated and non-coated seeds, regardless of water depth. These results suggest that iron-coated seeds are more appropriate for stable seedling establishment in direct water seeding than are non-coated seeds.

A Study on the theory of cosmos in ${\ulcorner}$Hwangje-Naegyeong(黃帝內經)${\lrcorner}$ ("황제내경(黃帝內經)"의 우주론(宇宙論)에 관(關)한 연구(硏究) - "황제내경(黃帝內經)"에 나타난 우주본체론(宇宙本體論)과 천체구조론(天體構造論)에 관한 연구-)

  • Kim, Shin-Hyung;Jang, Woo-Chang;Jeong, Chang-Hyun
    • Journal of Korean Medical classics
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    • v.19 no.3
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    • pp.184-197
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    • 2006
  • ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ described Tae Hue(太虛) cosmos which consist of the Great Gi(大氣) produce ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ which affected by the theory of activity of Gi(氣化說) in the Han period represent that Tae Hue is spring head of Gi(氣), concurrently said the Time and the Space were established by operating of Gi(氣). As of the Theories of heavenly structure, ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ was write in long perod, so it include three branch theory. ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ contained the Hypothesis of Covering Heaven(蓋天說), the Hypothesis of Armillary Sphere(渾天說) and the Hypothesis of Chaosheavens(宣夜說) in the Han perod. The Hypothesis of Covering Heaven(蓋天說) means that the sky is round and the ground falls Square(天圓地方). ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ involve the Hypothesis of Covering Heaven by the fact that it divide heaven and earth by top and bottom. The Hypothesis of Armillary Sphere(蓋天說) is not directly appeared in ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$. But ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ include the Hypothesis of Armillary Sphere by the astronomical observation and understand the universe with interior-exterior viewpoint. ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ describe the circulation of the universe (周天度數) at 365 1/4 terms, the length of daytime and night of the vernal equinox and the autumnal equinox is same and use the The Twenty Eight Constellations by the ecliptic(黃道). It prove that ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ observes the celestial body according to the Hypothesis of Armillary Sphere. The Hypothesis of Chaosheavens(宣夜說) appears most is the theory which lately. ${\ulcorner}$Hwangje-Naegyeong${\lrcorner}$ describe Tae Hue(太虛) infinite outer space and the earth is floating by Gi(氣). This with the Hypothesis of Chaosheavens is similar from like this point.

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A Study on Abalone Young Shells Counting System using Machine Vision (머신비전을 이용한 전복 치패 계수에 관한 연구)

  • Park, Kyung-min;Ahn, Byeong-Won;Park, Young-San;Bae, Cherl-O
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.4
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    • pp.415-420
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    • 2017
  • In this paper, an algorithm for object counting via a conveyor system using machine vision is suggested. Object counting systems using image processing have been applied in a variety of industries for such purposes as measuring floating populations and traffic volume, etc. The methods of object counting mainly used involve template matching and machine learning for detecting and tracking. However, operational time for these methods should be short for detecting objects on quickly moving conveyor belts. To provide this characteristic, this algorithm for image processing is a region-based method. In this experiment, we counted young abalone shells that are similar in shape, size and color. We applied a characteristic conveyor system that operated in one direction. It obtained information on objects in the region of interest by comparing a second frame that continuously changed according to the information obtained with reference to objects in the first region. Objects were counted if the information between the first and second images matched. This count was exact when young shells were evenly spaced without overlap and missed objects were calculated using size information when objects moved without extra space. The proposed algorithm can be applied for various object counting controls on conveyor systems.

Evaluation of Swine Wastewater Pretreatment Using Anaerobic Filter (Anaerobic Filter에 의한 양돈폐수의 전처리 특성 평가)

  • Kang, Ho;Moon, Seo-yeon
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.7
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    • pp.418-425
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    • 2015
  • Anaerobic Filters (AF) packed with porous ceramic floating media were operated at different operational conditions to identify the feasibility of the renewable bioenergy, methane production from swine wastewater and to verify the suitability of effluent from anaerobic filters for the subsequent biological nitrogen and phosphorus removal. Stepwise increase in organic loading rates (OLRs) or decrease in hydraulic retention times (HRTs) with influent TCOD concentration of 14,000 mg/L were utilized at mesophilic temperature. The maximum methane productivity of 1.74 volume of $CH_4$ per volume of reactor per day (v/v-d) was achieved at an hydraulic retention time (HRT) of 0.5 day (OLR 28 g TVS/L-d). Based on the biogas production, the highest total volatile solids (TVS) removal efficiency of 63% was obtained at an HRT of 3 days (OLR 4.67 g TVS/L-d), however based on the result from the effluent total chemical oxygen demand (TCOD) analysis, the highest TCOD removal efficiency of 75% was achieved. The effluent alkalinity concentration over the range of 2,050~2,980 mg/L as $CaCO_3$ at all operational conditions, could compensate the alkalinity destruction caused by nitrification. The effluent from the anaerobic filter operated under the HRT of 2 days showed the COD/TKN ratio of 15~35 and COD/TP ratio of 38~56. Therefore effluent C/N/P ratio is able to satisfy the optimum COD/TKN ratio of greater than 8.0 and COD/TP ratio of 33 for the subsequent biological nutrient removal.

A Study on the Dominant Driving Force of Plate Movement presented in the High School Earth Science Textbooks (고등학교 지구과학 교과서에 제시된 판 이동의 주된 원동력에 대한 고찰)

  • Jeon, Taehwan;Seo, Ki-Weon;Lee, Gyuho
    • Journal of the Korean earth science society
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    • v.37 no.1
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    • pp.62-77
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    • 2016
  • In the early model of plate tectonics, the plate was depicted as a passive raft floating on the convecting mantle and carried away by the mantle flow. At the same time, ridge push at spreading boundaries and drag force exerted by the mantle on the base of lithosphere were described as the dominant driving forces of plate movements. However, in recent studies of plate tectonics, it is generally accepted that the primary force driving plate motion is slab pull beneath subduction zones rather than other forces driven by mantle convection. The current view asserts that the density contrast between dense oceanic lithosphere and underlying asthenosphere is the substance of slab pull. The greater density of oceanic slab allows it to sink deeper into mantle at trenches by gravitational pull, which provides a dominant driving force for plate motion. Based on this plate tectonics development, this study investigated the contents of plate tectonics in high school Earth Science textbooks and how they have been depicted for the last few decades. Results showed that the early explanation of plate movement driven by mantle convection has been consistently highlighted in almost all high school textbooks since the 5th curriculum, whereas most introductory college textbooks rectified the early theory of plate movement and introduced a newly accepted theory in revised edition. Therefore, we suggest that the latest theory of plate tectonics be included in high school textbooks so that students get updated with recent understanding of it in a timely manner.

Tissue Distribution after dipping administration of Oxytetracycline and Tetracycline in Olive flounder (Paralichthys olivaceus), Rockfish (Sebastes schlegeli), and Red sea bream (Pagrus major) (Oxytetracycline과 Tetracycline의 약욕에 따른 양식어류 (넙치, 조피볼락, 참돔)의 조직내 잔류량의 변화)

  • Lee, Hu-Jang;Kim, Suk;Ha, Ji-Young;Kang, Seok-Jung;Jung, Won-Cheol;Chung, Hee-Sik;Heo, Sung-Hyek;Shin, Yong-Woon;Kim, Kyoung-Won;Kim, Dae-Geun
    • Journal of fish pathology
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    • v.19 no.2
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    • pp.155-164
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    • 2006
  • Tissue distribution and residue depletion of oxytetracycline (OTC) and tetracycline (TC) following dipping administration were evaluated in olive flounder (Paralichthys olivaceus), rockfish (Sebastes schlegeli), and red sea bream (Pagrus major) under field conditions. Fishes were held in floating cages placed in sea water and fed a commercial diet for 15 days to acclimate to a new surrounding. Fishes were dipped in OTC 50 g/ton water for 30min and TC 18 g/ton water for 5 hours. Blood and muscle were sampled from fishes on 0th, 1th, 2th, 3th, and 5th day after administration. After solid-phase extraction, OTC and TC analyses were carried out by HPLC. The recovery rate of OTC in serum and muscle samples was 71-77% and 78-84%, respectively. Also, the recovery rate of TC in serum and muscle samples was 70-79% and 73-78%, respectively. The results of recovery rate were similar to previous studies reported. At the termination of dipping administration of OTC and TC, residue concentration in muscle samples of rockfish was significantly higher than those of olive flounder and red sea bream. At day 5, residue concentrations of all samples were believed to decrease to lower than 0.05 mg/kg, the detection limit. The present study showed that residue concentrations of OTC and TC decreased to below 0.05 mg/kg after treatment 5th day, faster than the established withdrawal period. The tissue reside depletion time of dipping administration of OTC and TC seems to be shorter than those of oral or parenteral administration.