• Title/Summary/Keyword: $L^*$ Values

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A Study on the Epilithic Algae in a stream drained from Hot Springs (온천 주변 소형하천에 서식하는 부착조류군집에 관한 연구)

  • 최환석;유춘만
    • Journal of Environmental Health Sciences
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    • v.24 no.3
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    • pp.131-136
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    • 1998
  • Attached algal community and several physico-chemicai characters were investigated at Seokjong hot spring in Chollabukdo in February and in April, 1997. The results of physico-chemicai factors are as follows : water temperatures were varied from 6.5$^{\circ}$C to 32.0$^{\circ}$C; pH range was 6.9 to 7.7; The levels of electric conductivity were 105 $\mu$mhos/cm to 477 $\mu$mhos/cm; chemical oxygen demand(COD) range was 1.5 mg/l to 21.2 mg/l; ammonia concentration was 0.20 mg/l to 8.74 mg/l; nitrate concentrations were 0.36 mg/l to 2.43 mg/l; phosphate concentration was N.D. to 0.52 mg/l; sulfur concentration was 14.6 mg/l to 66.1 mg/l. Attacched algal species were identified. Totally, 63 taxa were classified and composed of 4 phylum, 4 class, 10 order, 17 family and 31 genera. The total biomass of attacched algae was $1.036 \times 10^{7}$ cells/l that composed of $5.39 \times 10^{6}$ cells/l of blue-green algae, $4.05 \times 10^{6}$ cells/l of diatom and $0.93 \times 10^{6}$ cells/l of green algae. The succession of dominant species was Synechocystis thermalis. This could be due to the thermal wastewaters. in biotic indices tests, the values of dominance index(DI) were 0.33 to 0.67 in winter, 0.18 to 0.68 in spring. The values of diversity index(H') were 1.44 to 2.69 in winter, 1.62 to 2.89 in spring. And the values of eveness index (J) were 0.31 to 0.61 in winter, 0.37 to 0.65 in spring.

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Lexical Status and the Degree of /l/-darkening

  • Ahn, Miyeon
    • Phonetics and Speech Sciences
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    • v.7 no.3
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    • pp.73-78
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    • 2015
  • This study explores the degree of velarization of English word-final /l/ (i.e., /l/-darkness) according to the lexical status. Lexical status is defined as whether a speech stimulus is considered as a word or a non-word. We examined the temporal and spectral properties of word-final /l/ in terms of the duration and the frequency difference of F2-F1 values by varying the immediate pre-liquid vowels. The result showed that both temporal and spectral properties were contrastive across all vowel contexts in the way of real words having shorter [l] duration and low F2-F1 values, compared to non-words. That is, /l/ is more heavily velarized in words than in non-words, which suggests that lexical status whether language users encode the speech signal as a word or not is deeply involved in their speech production.

Toxic Effects of Heavy Metals on the Growth and Phosphorus Removal Efficiency of Phosphorus Accumulating Microorganisms (PAOs)

  • Sin, Da Hee;Kim, Deok Hyeon;Kim, Jong In;Lee, Moon-Soon;Chung, Keun-Yook
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.6
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    • pp.673-680
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    • 2013
  • Phosphorus accumulating microorganisms (PAOs) are influenced by various environmental factors and heavy metals. This study was performed to evaluate the effects of the selected heavy metals on the growth and phosphorus removal capacity of Bacillus sp. 3434 BRRJ, Pseudomonas aerunogisa, and Bacillus Subtilis, well known as PAOs. The heavy metals used in this study included Cu, Cd, As, and Zn. The $IC_{50}$ (median inhibition concentration) values of Bacillus sp. 3434 BRRJ for the Cu, Cd, As, and Zn were 8.07 mg $L^{-1}$, 0.18 mg $L^{-1}$, 73.62 mg $L^{-1}$ and 0.25 mg $L^{-1}$, respectively. The $IC_{50}$ values of Pseudomonas aerunogisa for the Cu, Cd, As, and Zn were 4.45 mg $L^{-1}$, 0.16 mg $L^{-1}$, 18.51 mg $L^{-1}$ and 2.34 mg $L^{-1}$, respectively. The $IC_{50}$ values of Bacillus Subtilis for the Cu, Cd, As, and Zn were 3.81 mg $L^{-1}$, 0.18 mg $L^{-1}$, 11.31 mg $L^{-1}$ and 0.47 mg $L^{-1}$, respectively. The phosphorus removal efficiencies of the three bacteria, Bacillus sp. 3434 BRRJ, Pseudomonas aerunogisa, and Bacillus subtilis were 93.12%, 71.81%, and 65.31%, respectively. Based on the results of the three PAOs obtained from the study, it appears that Bacillus sp. 3434BRRJ may have the best results in terms of their growth rate and P removal efficiencies.

Using Shoulder Straps Decreases Heart Rate Variability and Salivary Cortisol Concentration in Swedish Ambulance Personnel

  • Karlsson, Kare J.;Niemela, Patrik H.;Jonsson, Anders R.;Tornhage, Carl-Johan A.
    • Safety and Health at Work
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    • v.7 no.1
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    • pp.32-37
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    • 2016
  • Background: Previous research has shown that paramedics are exposed to risks in the form of injuries to the musculoskeletal system. In addition, there are studies showing that they are also at increased risk of cardiovascular disease, cancer, and psychiatric diseases, which can partly be explained by their constant exposure to stress. The aim of this study is to evaluate whether the use of shoulder straps decreases physical effort in the form of decreased heart rate and cortisol concentration. Methods: A stretcher with a dummy was carried by 20 participants for 400 m on two occasions, one with and one without the shoulder straps. Heart rate was monitored continuously and cortisol samples were taken at intervals of 0 minutes, 15 minutes, 30 minutes, 45 minutes, and 60 minutes. Each participant was her or his own control. Results: A significant decrease in heart rate and cortisol concentration was seen when shoulder straps were used. The median values for men (with shoulder straps) at 0 minutes was 78 bpm/21.1 nmol/L (heart rate/cortisol concentration), at 15 minutes was 85 bpm/16.9 nmol/L, and at 60 minutes was 76 bpm/15.7 nmol/L; for men without shoulder straps, these values were 78 bpm/21.9 nmol/L, 93 bpm/21.9 nmol/L, and 73 bpm/20.5 nmol/L. For women, the values were 85 bpm/23.3 nmol/L, 92 bpm/20.8 nmol/L, and 70 bpm/18.4 nmol/L and 84 bpm/32.4 nmol/L, 100 bpm/32.5 nmol/L, and 75 bpm/25.2 nmol/L, respectively. Conclusion: The use of shoulder straps decreases measurable physical stress and should therefore be implemented when heavy equipment or a stretcher needs to be carried. An easy way to ensure that staff use these or similar lifting aids is to provide them with personalized, well-adapted shoulder straps. Another better option would be to routinely sewn these straps into the staff's personal alarm jackets so they are always in place and ready to be used.

Occupational Exposure to Metals in Shooting Ranges: A Biomonitoring Study

  • Vandebroek, Eline;Haufroid, Vincent;Smolders, Erik;Hons, Luc;Nemery, Benoit
    • Safety and Health at Work
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    • v.10 no.1
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    • pp.87-94
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    • 2019
  • Background: Lead (Pb) exposure in shooting ranges has been reduced by various measures such as jacketed ammunition and lead-free primers. Nevertheless, this may lead to exposure to other metals, potentially resulting in adverse health effects. Methods: In a cross-sectional study, 35 subjects from seven different shooting ranges were studied: four shooting instructors, 10 police officers, 15 Special Forces, and six maintenance staff members. Metals and metalloids were determined in blood and urine by inductively coupled plasma-mass spectrometry. Results: The concentrations of most elements did not differ significantly between groups or compared to reference values, except for Sb and Pt in urine and Pb in blood. Mean values for Sb were considerably higher in urine from the Special Forces ($0.34{\mu}g/L$), the maintenance staff ($0.13{\mu}g/L$), and shooting instructors ($0.32{\mu}g/L$) compared to the police officers before shooting ($0.06{\mu}g/L$) and a Belgian reference value ($0.04{\mu}g/L$). For Pt, the Special Forces showed higher mean urinary concentrations ($0.078{\mu}g/L$) compared to a Belgian reference value (<$0.061{\mu}g/L$). Mean values for blood lead were markedly higher in the Special Forces ($3.9{\mu}g/dL$), maintenance staff ($5.7{\mu}g/dL$), and instructors ($11.7{\mu}g/dL$) compared to police officers ($1.4{\mu}g/dL$). One instructor exceeded the biological exposure index for blood Pb ($38.8{\mu}g/dL$). Conclusion: Since both Pb and Sb were found to be higher in shooting range employees, especially among frequent shooters, it is advisable to provide appropriate protective equipment, education, and medical follow-up for shooting range personnel in addition to careful choice of ammunition.

Analysis of the Rectangular Microstrip Antenna with Parasitic Elements Considering the Mutual Coupling Characteristics (상호결합 특성이 고려된 기생소자를 갖는 구형 마이크로스트립 안테나 해석)

  • Son, Geon-Ho;Yun, Li-Ho;Hong, Jae-Pyo;Cho, Young-Ki;Son, Hyon
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.12
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    • pp.12-17
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    • 1991
  • In this paper, E-plane gap-coupled rectangular microstrip antennas with parasitic elements are analyzed. The mutual coupling between the radiating edges is represented as the voltage-dependent current source. The gap coupling between the patch and parasitic element is characterized with the REC(Radiating Edges-Coupling) model, and the conventional transmission line model is used to obtain the equivalent circuit of the antenna. The return loss of the rectangular microstrip antennas with short-and open-circuit parasitic elements are calculated and compared with the measured values. The theoretical values including the mutual coupling are more in agreement with the measured values than the calculated values without the mutual coupling.

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Test Pattern Generation for Combinational Circuits using Inherited Values (전수받은 값을 이용한 조합회로에 대한 검사 패턴 발생)

  • Song, Sang-Hun
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.2
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    • pp.606-615
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    • 1997
  • This paper proposes an dffcient method for test pattern generation.Current test pattern genration systems generate a test vester for fault $F_{i+l}$ independently of the computation previously done for faults F1,F2...,Fi The proposed algorithm generates a test vector for fault $F_{i+l}$ by inheriting the test vector for fault Fi. A new test vector is grnerated from inherited values by gradually changing the inhderited values .The inherited values may partially activate a fauog and propagate the fault signal,Normally,this reduses the number of decision steps and backtracks in the second search.Experimental results for well-Known benchmark circuts show that the proposed algorithm is very efficient with small backtrack kimit;in combination eith other algorithms,it is very efficient for arbitrary backtrack limits.

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Quality of Surface Water for lrrigation around Controlled Horticultural Area in Gyeongnam (경남지방 시설원예지 농업용 지표수의 수질 현황)

  • Heo, Jong-Soo;Ha, Yeong-Rae;Seo, Jeoung-Yoon;Cho, Ju-Sik;Lee, Sung-Tae;Lee, Hong-Jae
    • Korean Journal of Environmental Agriculture
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    • v.16 no.4
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    • pp.356-364
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    • 1997
  • To investigate the water quality status of agricultural water source for greenhouse area in Gyeongnam, the surface water quality was examined six times from October in 1995 to March in 1996 at five areas in Gyeongnam. The pH values of surface water were in the range of 6.6${\sim}$9.1 pH in Kimhae and Changnyong areas were out of range in 6.0${\sim}$8.5 which was water quality standard for agriculture. The DO values of surface water were relatively high with average 10.0mg/l in Kimhae, Changnyong, Sacheon and Chinju areas except for Haman area. The BOD values of surface water exceeded water quality standard for agriculture(8.0mg/l) in three sites and one site in Haman and Sacheon, respectively. The COD values of surface water exceeded water quality standard for agriculture(8.0mg/l) in Kimhae, Changnyong and Haman. The ${NH_4}^+-N$ values in surface water of Changnyong and Haman areas were 1.21mg/l and 2.75mg/l, respectively. The average values of $NO_3\;^--N$ in surface water was appropriate for agriculture. The values of $K^+,\;Na^+,\;Mg^{2+},\;Ca^{2+},\;{PO_4}^{3-}$ and $SO_4^{2-}$ in Haman were the highest of those of the others. And Pb was below 0.1mg/l which was water quality standard for agriculture. The average values of Cu, Cd and Zn were below water quality standard for agriculture. Between COD and SS in surface water was positively correlated with r$=0.799^{{\ast}{\ast}}$. BOD in surface water was positively correlated with $NH_4\;^+-N,\;PO_4\;^{3-},\;SS,\;K^+,\;Na^+$ and $Cl^-$. Surface water pollution status of agricultural water source of greenhouse areas in Gyeongnam was in order of Chinju< Sacheon< Kimhae< Changnyong< Haman area.

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Comparison of Nutritional Compositions and Antioxidant Activities of Building Blocks in Shinseoncho and Kale Green Vegetable Juices

  • Kim, Seong Yeong
    • Preventive Nutrition and Food Science
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    • v.17 no.4
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    • pp.269-273
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    • 2012
  • Shinseoncho and kale were divided into stem [shinseoncho stems (SS) and kale stems (KS)] and leaf parts [shinseoncho leaves (SL) and kale leaves (KL)] and made into green vegetable juices for analyses of nutritional compositions and antioxidant activities. Higher values of total acidity were observed in SL (0.736%) and KL (0.841%) than in SS (0.417%) and KS (0.335%) (p<0.05). Neutral sugar content showed higher values in SS (21.740 mg/mL) and SL (18.657 mg/mL) when compared with KS (1.497 mg/mL) and KL (1.452 mg/mL) (p<0.05). Protein content showed the highest value in SL (7.610 mg/mL) (p<0.05), while SS (0.403 mg/mL) and KS (0.403 mg/mL) showed similar lower values. Total polyphenol contents of SL (423.139 ${\mu}g/mL$) was significantly higher value (p<0.05) than those of other samples, which occurred in the following order: SL>KL (218.494 ${\mu}g/mL$) KS (107.269 ${\mu}g/mL$)>SS (75.894 ${\mu}g/mL$). KL exerted the highest DPPH radical scavenging activity (84.834%) (p<0.05), which occurred in the following order: KL>SL (63.473%)>KS (52.894%)>SS (35.443%). ABTS radical scavenging activity showed that SL (66.088%) and KL (38.511%) had higher scavenging activities, whereas SS (7.695%) and KS (9.609%) demonstrated to be lower activities (p<0.05). In general, leaf parts had much higher antioxidant activities as well as total polyphenol contents than those of the stem parts. In conclusion, shinseoncho and kale, particularly their leaf parts, offer antioxidant properties in green vegetable juices and the consumption of them may be beneficial as a nutrition source and in health protection.