• 한국환경보건학회지
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• 제48권1호
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• pp.44-51
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• 2022

Background: Air pollution is increasing together with industrialization and urbanization. In order to reduce air pollution, public transportation is recommended rather than private cars, and the number of passengers using public transportation is increasing accordingly. This study observes the concentration of indoor pollutants in city buses over time. Through this means, we intend to suggest a plan to manage the indoor air quality in city buses. Objectives: The concentration of indoor pollution in public transportation was investigated from April 2021 to January 2022. Based on this, we evaluated the exposure to indoor pollutants. Methods: Six city bus lines in an industrial city were selected for the research, and indoor pollution was measured through IoT (Internet of Things)-based sensor-type measuring devices. The concentration of pollutants was measured every minute, and statistical data were constructed based on the measurement results. Results: In all the city buses studied, the average concentration of pollutants were below the guidelines. However, some measurement results showed cases of exceeding the guidelines. As a result of the analysis by time zone, there were more cases in which pollutants exceeded the standard value during rush hour compared to at other times. A risk assessment for PM₁₀ was performed by evaluating the excess mortality risk from exposure and the risk from inhalation exposure. Conclusions: All measured indoor pollutants in the city buses did not exceed the guidelines. Also, the risk assessment results were found to be within the level of safety. However, if a city bus is used for a long time, there is a possibility that there may be an impact on the human body due to inhalation exposure, so additional management is required.

• Tuberculosis and Respiratory Diseases
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• 제65권6호
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• pp.476-486
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• 2008

연구배경: 정상세포는 보호되고 종양세포에 독성을 보인다고 알려진 TNF유전자족으로 새로이 확인된 TRAIL이 폐암세포에서 보이는 아포프토시스 효과를 확인하고, 아포프토시스로부터 세포를 보호하는 전사인자 $NF-{\kappa}B$가 TRAIL에 의하여 활성화 되는 정도를 평가하여 MG132의 $NF-{\kappa}B$활성억제가 TRAIL 유도성 아포프토시스를 감작시키는지를 확인하기 위하여 본 연구를 시행하였다. 방법: A549(wt p53) 및 NCI-H1299(null p53) 폐암세포주를 사용하였다. 세포독성 검사는 MTT assay를 이용하였고 아포프토시스는 Annexin V assay와 FACS 분석을 이용하였다. $NF-{\kappa}B$ 전사활성은 luciferase reporter gene assay를 이용하였고 $I{\kappa}B{\alpha}$ 분해는 western blot을 이용하였으며, TRAIL에 의해 활성화된 $NF-{\kappa}B$와 DNA 결합은 electromobility shift assay와 anti-p65 antibody를 이용한 supershift assay로 확인하였다. 결과: 1) TRAIL 100 ng/ml 농도에서 wild-type p53인 A549 폐암세포는 34.4%, p53 null인 NCI-H1299 폐암세포는 26.4%의 세포사를 관찰하였다. 2) Luciferase reporter gene assay로서 TRAIL에 의한 $NF-{\kappa}B$의 활성이 A549 $IgG{\kappa}B-luc$세포에서 2.45배 증가하고 NCI-H1299 $IgG{\kappa}B-luc$세포에서는 1.47배 증가함을 관찰하여 TRAIL에 의하여 $NF-{\kappa}B$가 활성화됨을 확인하였다. 3) MG132의 전처치로 TRAIL에 의한 $NF-{\kappa}B$의 활성이 A549 세포와 NCI-H1299 세포에서 각각 기저수준의 0.24, 0.21배로 강력히 억제되었다. 4) TRAIL단독으로 30% 전후의 세포독성이 MG132 전처치 후 TRAIL을 투여하면 두 세포주 모두에서 80% 이상의 세포독성이 관찰되어 MG132가 TRAIL유도성 아포프토시스에 감작효과가 있음을 확인하였다. 결론: 이상의 결과로 TRAIL에 상대적인 내성을 보이는 폐암세포주에서 MG132가 $NF-{\kappa}B$ 활성억제로서 TRAIL유도성 아포프토시스를 강화시키는 효과가 있음을 확인할 수 있었다. 따라서 본 연구는 향후 폐암치료에 있어서 TRAIL유도성 아포프토시스가 이용될 수 있는 가능성을 확인한 기초자료가 된다고 생각된다.

• 치과방사선
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• 제29권2호
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• pp.435-449
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• 1999

Purpose : The study was aimed to detect the differences in the cell viability and the apoptosis induction after irradiation on normal and tumorigenic cells. Materials and Methods : The study. that was generated for two human normal cells(RHEK, HGF-l) and two human tumor cells(KB. HT-1080). was tested using MTT assay at 1 day and 3 day after irradiation and TUNEL assay under confocal laser scanning microscope at 1 day after irradiation. Single irradiation of 0.5. 1, 2. 4. and 8Gy were applied to the cells. The two fractions of 1. 2. 4. and 8Gy were separated with a 4-hour time interval. The irradiation was done with 5.38Gy/min dose rate using Cs-137 irradiator at room temperature. Results and Conclusions : 1. In 3-day group. the cell viability of HGF-1 cell was significantly decreased at 2. 4 and 8Gy irradiation, the cell viability of KB cell was significantly decreased at 8Gy irradiation and the cell viability of HT-I080 cell was significantly decreased at 4 and 8Gy irradiation. 2. There was significant difference between RHEK and KB cell line in the cell viability of 3-day group at 8Gy irradiation. There was significant difference between RHEK and HGF-1 cell line in the cell viability of 3-day group at 4 and 8Gy irradiation. 3. There was a significantly decreased cell viability in 3-day group than those in 1-day group at 2. 4 and 8Gy on HGF-1 cell. at 4 and 8Gy on HT-I080 cell. at 8Gy on KB cell. 4. We could detect DNA fragmented cells only on KB cell. Number of apoptotic cells of KB cell was significantly increased at 4 and 8Gy irradiation. However, there was no correlation between cell viability and apoptosis. 5. On all 4 cell lines, there were no differences between single and split irradiation method in cell viability and apoptosis.

• 한국환경보건학회지
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• 제31권5호
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• pp.379-386
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• 2005

[ $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ ] in driver cabins of subway line from 5 to 8 were monitored from 07:00 through 21:00 (or 19:30 or 20:00) on May. Driver cabin of subway line 7 showed the highest $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ concentrations. General Linear Model indicated that subway line, subway location (ground and underground track) and running time (morning and afternoon) significantly influenced the concentrations of $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ (p=0.000). Daily profile of $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$, expressed as an 30 minutes average, showed similar variation pattern over day period. These concentrations showed the highest concentrations between 07:00 and 09:00 of rush hour, slightly dropped and again rose slightly after 18:00. In correlation analysis, significant relations among $PM_{10},\;PM_{2.5},\;CO_2\;and\;CO$ were detected (p<0.01). In particular, correlation coefficient between $PM_{10}\;and\;PM_{2.5}$ was highly significant (r=0.884). Regression analysis also concluded that $PM_{10}$ concentration significantly explained 71.4% of variation of $PM_{2.5}$ concentration (p=0.000, $R^2=0.714$). Correlations by CO with $PM_{10}\;and\;PM_{2.5}$ were 0.451 and 0.520, which were higher than those by $CO_2$. Further study is needed to examine the sources of $PM_{2.5}$ and CO in subway and to compare pollutants concentration among subway lines.

• 생물환경조절학회지
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• 제18권3호
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• pp.225-231
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• 2009

지표관수와 비교하여 지중관수 및 지중관수 시 공기주입의 효과를 검토하고자 '녹광' 풋고추를 온실 내에서 토양재배(silty loam)하여 관수효율, 토양특성, 과실 생육 및 수량 등을 조사하였다. 관수방법은 관수호스를 이랑당 2열 배열하되 지표관수는 토양표면, 지중관수는 지표 20cm 아래에 설치하였고, 공기주입은 air compressor를 이용하여 낮 동안에 시간당 3분간 주입하였다. 관수는 콘트롤러, 전자식 토양수분장력센서 등을 이용, 토양수분에 기초한 자동관수를 실시하였는데, 관수개시점은 -20kPa, 관수종료점을 -10kPa로 설정하여 관리하였다. 그 결과, 토양수분의 감소속도가 지표 관수에 비해 지중관수와 지중관수 +공기주입이 늦었으며, 관수량도 지중관수가 지표환수에 비해 지표면에서의 증발 감소 등으로 약 30% 적었다. 표토층의 EC 및 무기이온함량은 지표관수에 비해 지중관수나 지중관수 +공기주입이 낮은 수준이었다. 뿌리의 발달은 지표관수에 비해 지중관수+공기주입한 것이 가장 좋았는데, 특히 뿌리가 길고 세근의 발달이 많았다. 이로 인해 풋고추 수량이 지표관수에 비해 지중관수가 22%, 지중관수 +공기주입이 30% 각각 증가되었다.

• 한국수산과학회지
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• 제2권2호
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• pp.161-172
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• 1969

Ten experimental tuna long line fishing operations were performed with the long lines A and B, in combination casting orders of BA and AB. The long line B differs from A in its additional main line length per basket and its greater depth of submersion (Table 1). The BA casting order results in an AB hauling order, so that the long line B is casted at an earlier time of a day and fishes for a longer period than A line (fig. 2). The number of fish caught was divided into subclasses in order to be subjected to $x^2-tests$ (Table 2). The first series of $x^2-tests$ were calculated using the hooking rates of two subclasses with other factors pooled (Table 3). The second series of $x^2-tests$ were calculated to obtain the interactions between two subclasses when other factors differed (Table 4). Attention was paid to the extremely small interactions as well as to the large interactions in order to find out whether a factor functions in the same way or in a contradictory way when the other factors involved differ. The test result is summarized in Table 5. The relationship between the hook casting time (relative to the sunrise time) and the hooking rates reveals the feeding behavior of particular species (fig. 3) A high hooking rate for yellowfin tuna shown in the period from one hour before sunrise to the moment of sunrise suggests that they feed actively in that period. Their poor hooking rate on earlier casted hooks suggests that they do not feed well under conditions of darkness and that they feed best while the hooks are sinking. Furthermore it is likely that yellowfin tuna maintain a shallow depth in the daytime, for the $x^2$ interaction between the line casting order BA and AB shows their persistant preferance of the long line A regardless of line casting order. Bigeye tuna show their feeding behavior under conditions of darkness, and show a preference for the sea's deeper layer. Alepisaurus borealis (Gill) show their feeding behavior under conditions of darkness more significantly than the bigeye tuna and their preferance for deep layers is also more significant. Marlins (mainly Makaria mazara) show a feeding behavior which is similar to the yellowfin tuna. The author emphasizes that certain variations of the hooking rates in relation to the line easting time were caused by an inadequate fishing depth as well as by the fish preference for a particular feeding time. When the part of the line casted in pre-dawn hours and hauled in the pre-sunset hours show a significantly lower hooking rate than other parts of the line, then it is concluded that tile hooks settled in a sea layer too deep for feeding.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.431-432
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• 2012

In the era of 20 nm scaled semiconductor volume manufacturing, Microelectronics Manufacturing Engineering Education is presented in this paper. The purpose of microelectronic engineering education is to educate engineers to work in the semiconductor industry; it is therefore should be considered even before than technology development. Three Microelectronics Manufacturing Engineering related courses are introduced, and how undergraduate students acquired hands-on experience on Microelectronics fabrication and manufacturing. Conventionally employed wire bonding was recognized as not only an additional parasitic source in high-frequency mobile applications due to the increased inductance caused from the wiring loop, but also a huddle for minimizing IC packaging footprint. To alleviate the concerns, chip bumping technologies such as flip chip bumping and pillar bumping have been suggested as promising chip assembly methods to provide high-density interconnects and lower signal propagation delay [1,2]. Aluminum as metal interconnecting material over the decades in integrated circuits (ICs) manufacturing has been rapidly replaced with copper in majority IC products. A single copper metal layer with various test patterns of lines and vias and $400{\mu}m$ by $400{\mu}m$ interconnected pads are formed. Mask M1 allows metal interconnection patterns on 4" wafers with AZ1512 positive tone photoresist, and Cu/TiN/Ti layers are wet etched in two steps. We employed WPR, a thick patternable negative photoresist, manufactured by JSR Corp., which is specifically developed as dielectric material for multi- chip packaging (MCP) and package-on-package (PoP). Spin-coating at 1,000 rpm, i-line UV exposure, and 1 hour curing at $110^{\circ}C$ allows about $25{\mu}m$ thick passivation layer before performing wafer level soldering. Conventional Si3N4 passivation between Cu and WPR layer using plasma CVD can be an optional. To practice the board level flip chip assembly, individual students draw their own fan-outs of 40 rectangle pads using Eagle CAD, a free PCB artwork EDA. Individuals then transfer the test circuitry on a blank CCFL board followed by Cu etching and solder mask processes. Negative dry film resist (DFR), Accimage$^{(R)}$, manufactured by Kolon Industries, Inc., was used for solder resist for ball grid array (BGA). We demonstrated how Microelectronics Manufacturing Engineering education has been performed by presenting brief intermediate by-product from undergraduate and graduate students. Microelectronics Manufacturing Engineering, once again, is to educating engineers to actively work in the area of semiconductor manufacturing. Through one semester senior level hands-on laboratory course, participating students will have clearer understanding on microelectronics manufacturing and realized the importance of manufacturing yield in practice.

• 한국약용작물학회지
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• 제18권6호
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• pp.421-428
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• 2010

The bark of Berberis koreana Palibin was fermented by Bifidobacterium longum B6 and Lactobacillus paracasei at $37^{\circ}C$ for 72 hour, then extracted by water solvent at $100^{\circ}C$ for 180 min. Total pholyphenol and flavonoid contents were improved by fermentation process, compared to conventional water extraction. The barks of B. koreana Palibin extracts by B. longum B6 (FE-B.L.) and by L. paracasei (FE-L.P.) showed 17% and 16% cytotoxicity on human normal cell lines(HEK293) at 1.0 mg/$m{\ell}$ of the highest concentration, respectively, which was about 3~5% lower than 20% from normal extracts (NE). DPPH radical scavenging activity of the FE-B.L. and FE-L.P. were about 73% and 75.9% higher than 56.8% of NE. The highest inhibitory potency on xathine oxidase and superoxide dismutase (SOD)-like activities were also measured as 31.9% and 61.9% by adding FE-L.P. of 1.0 mg/$m{\ell}$. On tyrosinase inhibition test, the FE-L.P. showed highest activity as 75.9% at 1.0 mg/$m{\ell}$. Generally, FE-L.P. showed higher antioxidant activities as well as higher tyrosinase inhibition activity, possibly due to high contents of total pholyphenol and flavonoid. In general, fermentation of barks of B. koreana Palibin has relatively better biological activities than normal extracts. Specifically, the extracts fermented by L. paracasei showed higher activities than that from B. longum B6.

• 천문학회보
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• 제37권2호
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• pp.113.1-113.1
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• 2012

The characteristics of Doppler shifts in a quiet region of the Sun are investigated by comparing between the $H{\alpha}$ line and the Caii infrared line at 854.2 nm. A small area of $16^{\prime\prime}{\times}40^{\prime\prime}$ was observed for about half an hour with the Fast Imaging Solar Spectrograph (FISS) of the 1.6 meter New Solar Telescope (NST) at Big Bear Solar Observatory. The observed area contains a network region and an internetwork region, and identified in the network region are $H{\alpha}$ fibrils, Caii fibrils and bright points. We infer the Doppler velocity from each line profile at a point with the lambdameter method as a function of half wavelength separation ${\Delta}{\lambda}$. It is confirmed that the bisector of the spatially-averaged Caii line profile has an inverse C-shape of with a significant peak redshift of +1.8 km/s. In contrast, the bisector of the spatially-averaged $H{\alpha}$ line profile has a different shape; it is almost vertically straight or, if not, has a C-shape with a small peak blueshift of -0.5 km/s. In both the lines, the bisectors of bright network points are much different from those of other features in that they are significantly redshifted not only at the line centers, but also at the wings. We also find that the spatio-temporal fluctuation of Doppler shift inferred from the Caii line is correlated with those of the $H{\alpha}$ line. The strongest correlation occurs in the internework region, and when the inner wings rather than the line centers are used to determine Doppler shift. In this region, the RMS value of Doppler shift fluctuation is the largest at the line center, and monotonically decreases with ${\Delta}{\lambda}$. We discuss the physical implications of our results on the formation of the $H{\alpha}$ line and Caii 854.2 nm line in the quiet region chromosphere.

• 한국ITS학회 논문지
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• 제17권6호
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• pp.133-143
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• 2018

회전교차로(Roundabouts)는 비교적 교통량과 보행자가 적은 교차로에 신호등 없이 설치되어 원형교통섬을 한 방향으로 회전하여 통행하는 비신호 교차로이다. 회전교차로 설치이후 비정상적인 교통수요 발생 및 보행량 증가 시 운영효율성 감소에 따른 대처방안으로 회전교차로 신호미터링(Signal Metering)에 대한 연구가 다수 진행되고 있다. 그러나 기존의 신호미터링 운영 알고리즘(Algorithm)은 양보선과 검지기간 사각지대 및 회전차로에 존재하는 차량의 대기행렬을 고려하지 못하는 단점이 존재한다. 따라서 본 연구에서는 대기행렬 소거시간(Queue Clearance Time)을 고려한 실시간 회전교차로 신호미터링 운영 알고리즘을 제시하고 VISSIM의 Com-Interface를 활용하여 그 효과를 분석하였다. 분석결과 총 진입교통량 3,200~4,800대/시에 대기행렬 소거시간 21~50초를 적용 시 차량 당 평균지체가 16.1~71.7%까지 크게 감소하는 것으로 분석되었다.