• Title/Summary/Keyword: Relationship Quality

Search Result 6,058, Processing Time 0.04 seconds

Radiation Therapy for Bone Metastases from Hepatocellular Carcinoma: Effect of Radiation Dose Escalation (간세포암에 의한 뼈전이의 방사선치료: 고선량 방사선치료의 효과)

  • Kim, Tae-Gyu;Park, Hee-Chul;Lim, Do-Hoon;Kim, Cheol-Jin;Lee, Hye-Bin;Kwak, Keum-Yeon;Choi, Moon-Seok;Lee, Joon-Hyoek;Koh, Kwang-Cheol;Paik, Seung-Woon;Yoo, Byung-Chul
    • Radiation Oncology Journal
    • /
    • v.29 no.2
    • /
    • pp.63-70
    • /
    • 2011
  • Purpose: To evaluate the extent of pain response and objective response to palliative radiotherapy (RT) for bone metastases from hepatocellular carcinoma according to RT dose. Materials and Methods: From January 2007 to June 2010, palliative RT was conducted for 103 patients (223 sites) with bone metastases from hepatocellular carcinoma. Treatment sites were divided into the high RT dose and low RT dose groups by biologically effective dose (BED) of 39 $Gy_{10}$. Pain responses were evaluated using the numeric rating scale. Pain scores before and after RT were compared and categorized into 'Decreased', 'No change' and 'Increased'. Radiological objective responses were categorized into complete response, partial response, stable disease and progression using modified RECIST (Response Evaluation Criteria In Solid Tumors) criteria; the factors predicting patients' survival were analyzed. Results: The median follow-up period was 6 months (range, 0 to 46 months), and the radiologic responses existed in 67 RT sites (66.3%) and 44 sites (89.8%) in the high and low RT dose group, respectively. A dose-response relationship was found in relation to RT dose (p=0.02). Pain responses were 75% and 65% in the high and low RT dose groups, respectively. However, no statistical difference in pain response was found between the two groups (p=0.24). There were no differences in the toxicity profiles between the high and low RT dose groups. Median survival from the time of bone metastases diagnosis was 11 months (range, 0 to 46 months). The Child-Pugh classification at the time of palliative RT was the only significant predictive factor for patient survival after RT. Median survival time was 14 months under Child-Pugh A and 2 months under Child-Pugh B and C. Conclusion: The rate of radiologic objective response was higher in the high RT dose group. Palliative AT with a high dose would provide an improvement in patient quality of life through enhanced tumor response, especially in patients with proper liver function.

Applied-Mineralogical Characterization and Assessment of Some Domestic Bentonites (I): Mineral Composition and Characteristics, Cation Exchange Properties, and Their Relationships (국내산 벤토나이트에 대한 응용광물학적 특성 평가 (I): 광물 조성 및 특징과 양이온 교환특성과의 연계성)

  • 노진환
    • Journal of the Mineralogical Society of Korea
    • /
    • v.15 no.4
    • /
    • pp.329-344
    • /
    • 2002
  • Mineralogical and chemical characterization of some domestic bentonites, such as quantitative XRD analysis, chemical leaching experiments, pH and CEC determinations, were done without any separation procedures to understand their relationships among mineral composition, characteristics, and cation exchange properties. XRD quantification results based on Rietveld method reveal that the bentonites contain totally more than 25 wt% of impurities, such as zeolites, opal-CT, and feldspars, in addition to montmorillonite ranging 30~75 wt%. Cation exchange properties of the zeolitic bentonites are deeply affected by the content of zeolites identified as clinoptilolite-heulandite series. Clinoptilolite is common in the silicic bentonites with lighter color. and occurs closely in association with opal-CT. Ca is mostly the dominant exchangeable cation, but some zeolitic bentonites have K as a major exchangeable cation, The values of cation exchange capacity (CEC) determined by Methylene Blue method are comparatively low and have roughly a linear relationship with the montmorillonite content of the bentonite, though the correlated data tend to be rather dispersed. Compared to this, the CEC determined by Ammonium Acetate method, i.e.‘Total CEC’, has much higher values (50~115 meq/100 g). The differences between those CEC values are much greater in zeolitic bentonites, which obviously indicates the CEC increase affected by zeolite. Other impurities such as opal-CT and feldspars seem to affect insignificantly on the CEC of bentonites. When dispersed in distilled water, the pH of bentonites roughly tends to increase up to 9.3 with increasing the alkali abundance, especially Na, in exchangeable cation composition. However, some bentonites exhibit lower pH (5~6) so as to regard as ‘acid clay’. This may be due to the presence of $H^{+}$ in part as an exchangeable cation in the layer site of montmorillonite. All the works of this study ultimately suggest that an assesment of domestic bentonites in grade and quality should be accomplished through the quantitative XRD analysis and the ‘Total CEC’measurement.

The Effect of Dietitian종s Leadership on the Job Satisfaction of Employees in Foodservice Organizations (영양사의 리더십과 조리종사원의 직무만족도에 관한 연구)

  • Kim, Eun-Mi;Chun, Soon-Sil;Yoon, Ji-Young
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.33 no.10
    • /
    • pp.1646-1652
    • /
    • 2004
  • This study is to help management of foodservices with the means of preparing a favorable food service environment which will likely improve employees' job satisfaction and present the plans for Quality leadership which are capable of effectively improving the aims of food service. Transformational leadership (4.08) that includes charisma (4.12), intellectual stimulation (4.12) and individual consideration (4.01) was more strongly observed by employees than transactional leadership (3.35) that includes contingent reward (3.99) and management by exception (2.70). According to employees' age, it was shown that individuals over 40 observed transformational leadership significantly more frequently than those below 30. When considering academic background, both transformational leadership and transactional leadership were more strongly observed in the group of lower education. When the type of employment was considered, contract workers showed higher individual consideration and contingent reward than regular workers. Also, when the consideration of working places was taken into account, employees who were employed by schools presented a stronger observance of transactional leadership than employees in industrial cooperation or hospitals. Employees, especially in schools, were more receptive to dietitians' contingent reward than hospital employees. Regarding age, dietitians below the age of 40 had stronger transformational leadership skills, but there was no significant difference in the case of transactional leadership. According to these items of leadership, dietitians over 40 felt stronger in management without exception. Relationship with co-workers was the highest among job satisfaction (3.84), coworkers (4.00), stability (3.60), autonomy (3.76). In the collective food service organization, there was a positive correlation between management expectations and the expectations of the dietitians' management styles and employees' job satisfaction.

Determination of Optimun Coagulant Dosage for Effective Water Treatment of Chinyang Lake -The Effect of Coagulant Dosing on Remoaval of Colloidal Pollutants- (진양호소수의 효과적인 정수처리를 위한 최적응집제 주입량 결정 -콜로이드성 오염물질 처리를 위한 응집제 주입효과-)

  • 이원규;조주식;이홍재;허종수
    • Journal of Environmental Science International
    • /
    • v.7 no.6
    • /
    • pp.761-772
    • /
    • 1998
  • This study was performed to determine the optimum coagulant dosing amount for effective treatment of raw water. The removal rate of turbidity and the variations of water qualities according to various dosage of coagulants such as Alum, PAC and PACS were investigated. The optimum coagulant dosing amount to make the lowest turbidity of water were 35mg/ι t of Alum, 30mg/ι of PAC and 10mg/ι of PACS in case of 5 NTU of raw water turbidity, and 30mg/ι of Alum, 25mg/ι of PAC and 10mg/ι of PACS in case of 10 NTU of that, respectively. The removal rates of turbidity at 4 min. and 8 min. of settling time were 10 and 72% of Alum, 44 and 62% of PAC and 25 and 55% of PACS in case of 5 NTU, and 52 and 70% of Alum, 90 and 95% of PAC and 10 and 28% of PACS in case of 10 NTU, respectively. Judging from the settling capability of floc., the reaction time of floe. formation and removal efficiency of turbidity, PAC was evaluated as more effective coagulant than Alum and PACS. Also PAC was regarded as the most effective coagulant when the water supply was changed sharply and the fluctuation of the surface loading occured with wide and sharp in settling basin. pH and alkalinity of the water were decreased with increasing coagulants dosage. But pH and alkalinity were not decreased below 5.8 which is the standard for drinking water quality, and 10mg/ι which is the limit concentration of floc. breakage, respectively. Residual Al of the treated water was decreased with increasing coagulants dosage in case of 5 and 10NTU of raw water turbidity. $KMnO_4$ consumption of the water was decreased with increasing coagulants dosage. The reduction rate of $KMnO_4$ consumption at the optimum coagulants dosage were 39% of Alum. 18% of PAC and 11% of PACS in case of 5 NTU of raw water turbidity, and 42% of Alum, 27% of PAC and 36% of PACS in case of 10 NTU of that, respectively. Any relationship was not found between the removal rate of turbidity and KMnO$_4$ consumption. TOC of the water was a bit decreased with increasing coagulants dosage up to 30mg/ι but not changed above 30mg/ι of coagulants dosage. The degree of TOC reduction was increased in the order of Alum, PAC and PACS treatment. Zeta potential of the colloidal floe. at the optimum coagulants dosage was in the range of -20~-15mV in case of 5 NTU of raw water turbidity and 0~0.5mV in case of 10 NTU of that. respectively. Although the kinds and dosages of coagulants were different, zeta potential range were fixed under the conditions of the best coagulation efficiency.

  • PDF

Recommending Core and Connecting Keywords of Research Area Using Social Network and Data Mining Techniques (소셜 네트워크와 데이터 마이닝 기법을 활용한 학문 분야 중심 및 융합 키워드 추천 서비스)

  • Cho, In-Dong;Kim, Nam-Gyu
    • Journal of Intelligence and Information Systems
    • /
    • v.17 no.1
    • /
    • pp.127-138
    • /
    • 2011
  • The core service of most research portal sites is providing relevant research papers to various researchers that match their research interests. This kind of service may only be effective and easy to use when a user can provide correct and concrete information about a paper such as the title, authors, and keywords. However, unfortunately, most users of this service are not acquainted with concrete bibliographic information. It implies that most users inevitably experience repeated trial and error attempts of keyword-based search. Especially, retrieving a relevant research paper is more difficult when a user is novice in the research domain and does not know appropriate keywords. In this case, a user should perform iterative searches as follows : i) perform an initial search with an arbitrary keyword, ii) acquire related keywords from the retrieved papers, and iii) perform another search again with the acquired keywords. This usage pattern implies that the level of service quality and user satisfaction of a portal site are strongly affected by the level of keyword management and searching mechanism. To overcome this kind of inefficiency, some leading research portal sites adopt the association rule mining-based keyword recommendation service that is similar to the product recommendation of online shopping malls. However, keyword recommendation only based on association analysis has limitation that it can show only a simple and direct relationship between two keywords. In other words, the association analysis itself is unable to present the complex relationships among many keywords in some adjacent research areas. To overcome this limitation, we propose the hybrid approach for establishing association network among keywords used in research papers. The keyword association network can be established by the following phases : i) a set of keywords specified in a certain paper are regarded as co-purchased items, ii) perform association analysis for the keywords and extract frequent patterns of keywords that satisfy predefined thresholds of confidence, support, and lift, and iii) schematize the frequent keyword patterns as a network to show the core keywords of each research area and connecting keywords among two or more research areas. To estimate the practical application of our approach, we performed a simple experiment with 600 keywords. The keywords are extracted from 131 research papers published in five prominent Korean journals in 2009. In the experiment, we used the SAS Enterprise Miner for association analysis and the R software for social network analysis. As the final outcome, we presented a network diagram and a cluster dendrogram for the keyword association network. We summarized the results in Section 4 of this paper. The main contribution of our proposed approach can be found in the following aspects : i) the keyword network can provide an initial roadmap of a research area to researchers who are novice in the domain, ii) a researcher can grasp the distribution of many keywords neighboring to a certain keyword, and iii) researchers can get some idea for converging different research areas by observing connecting keywords in the keyword association network. Further studies should include the following. First, the current version of our approach does not implement a standard meta-dictionary. For practical use, homonyms, synonyms, and multilingual problems should be resolved with a standard meta-dictionary. Additionally, more clear guidelines for clustering research areas and defining core and connecting keywords should be provided. Finally, intensive experiments not only on Korean research papers but also on international papers should be performed in further studies.

Effects of Temperature and Light Intensity on the Growth of Red Pepper(Capsicum annuum L.) in Plastic House During Winter. II. Effects of Temperature and Light Environment on the Early Growth and Yield of Red Pepper under the Multilayered Covering in Non - heated Plastic House (동계 Plastic house내 고추(Capsicum annuum L.) 육묘시 온도와 광도가 생장에 미치는 영향 II. 무가온 다중피복 시설내 온도 및 광환경이 고추의 유묘생장 및 수량에 미치는 영향)

  • 정순주;이범선;권용웅
    • Journal of Bio-Environment Control
    • /
    • v.3 no.2
    • /
    • pp.119-127
    • /
    • 1994
  • This study was conducted to investigate the effects of temperature and light conditions on the vigor and growth responses of red pepper(Capsicum annuum L.) seedlings in the nonheated plastic houses with triple and quadruple coverings during winter. The results obtained were as follows ; 1. The growth in terms of plant height, number of leaves, leaf area and dry weight of each organ was reduced up to 50% in the triple coverings compared to quadruple ones. The greatest difference between the triple coverings and quadruple ones was the leaf area, showing two to five times larger in the quadruple ones. Therefore, the differences of the early environmental conditions during raising seedling stage was well reflected. 2. The leaf expansion in the early stage of seedling was delayed in the triple coverings and subsequently crop growth rate(CGR) significantly reduced. The specific leaf area (SLA) in the triple coverings was less than quadruple ones. The net assimilation rate (NAR) was increased in the early stage of seedlings and then reduced in the quadruple coverings. In triple ones, however, the great reduction showed at six weeks after sowing and then increased sharply. 3. The linear relationship among leaf area, total dry weight and leaf dry weight was observed in the all experimental areas, while between leaf area and crop growth rate only in the quadruple coverings, and between leaf area and net assimilation rate in both triple and quadruple ones. 4. The dry matter partitioned to the leaf increased up to six weeks after sowing in the triple coverings but reduced in the stem and root. However, the adverse results were obtained in the quadruple ones. 5. In the triple coverings, the number of branches showed the exponential increment while fruit weight showed linear increment in both triple and quadruple ones. Higher yield was obtained in the quadruple ones. 6. The shoot dry weight among the characteristics of seedlings was greatly contributed to the yield of red pepper after transplanting. Accordingly, one of the decisive criterion for good quality of red pepper seedlings was determined by the highest correlation between shoot dry weight of growing plant and fruit yield of pepper plant.

  • PDF

A Study on the Efficient Measurement of Airborne Asbestos Concentrations at Demolition Sites of Asbestos Containing Buildings, etc. in Seoul (서울시내 석면함유 건축물 철거 현장 등에서의 효과적인 공기 중 석면농도 측정을 위한 연구)

  • Lee, Jinhyo;Lee, Suhyun;Kim, Jeongyeun;Kim, Jihui;Chung, Sooknye;Kim, Jina;Oh, Seokryul;Kim, Iksoo;Shin, Jinho;Eo, Soomi;Jung, Kweon;Lee, Jinsook
    • Journal of Korean Society of Occupational and Environmental Hygiene
    • /
    • v.24 no.2
    • /
    • pp.113-121
    • /
    • 2014
  • Objectives: This study is intended to seek credible and efficient measurements on airborne asbestos concentrations that allow immediate action by establishing complementary data through comparative analysis with existing PCM and KF-100 method real-time monitoring equipment in working areas in Seoul where asbestos-containing buildings are being demolished, including living environment surroundings. Materials: We measured airborne asbestos concentrations using PCM and KF-100 at research institutes, monitoring networks, subway stations and demolition sites of asbestos-containing buildings. Through this measurement data and KF-100 performance testing, we drew a conversion factor and applied it via KF-100. Finally we verified the relationship between PCM and KF-100 with statistical methods. Results: The airborne asbestos concentrations by PCM for the objects of study were less than the detection limit(7 fiber/$mm^2$) in three (20%) out of 15 samples. The highest concentration was 0.009 f/cc. The airborne asbestos concentrations by PCM in laboratories, monitoring networks, subway stations and demolition sites of asbestos-containing buildings were respectively $0.002{\pm}0.000$ f/cc, $0.004{\pm}0.001$ f/cc, $0.009{\pm}0.001$ f/cc, and $0.002{\pm}0.000$ f/cc. As a result of KF-100 performance testson rooftops, the conversion factor was 0.1958. Applying the conversion factor to KF-100 for laboratories, the airborne asbestos concentrations ratio of the two ways was nearly 1:1.5($R^2$=0.8852). Also,the airborne asbestos concentration ratio of the two ways was nearly 1:1($R^2$=0.9071) for monitoring networks, subway stations, and demolition sites of asbestos-containing buildings. As a result of independent sample t-tests, there was no distinction between airborne asbestos concentrations monitored in the two ways. Conclusions: In working areas where asbestos-containing buildings are being demolished, including living environment surroundings, quickly and accurately monitoring airborne asbestos scattered in the air around the working area is highly important. For this, we believea mutual interface of existing PCM and a real-time monitoring equipment method is possible.

Pollutant Contents with Particle Size Distribution in Bridge Road Drainage Sediment (교량도로 배수받이 퇴적물질의 입경별 오염물질 함량)

  • Lee, Jun-Ho;Cho, Yong-Jin;Bang, Ki-Woong
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.29 no.12
    • /
    • pp.1360-1365
    • /
    • 2007
  • The purpose of this study is to present the basic data for nonpoint pollutant loads from bridge road drainage sediments using the results to analyze organic matter and heavy metals from the four bridge drainage sampling sites with sediments of different particle size ranges. The sediment sample was collected from the bridge road drainage and the masses of nine sediments fractions were obtained after drying the separated sediment in an over at $85^{\circ}C:>2,000{\mu}m$, $1,000\sim2,000{\mu}m$, $850\sim1,000{\mu}m$, $425\sim850{\mu}m$, $212\sim425{\mu}m$, $125\sim212{\mu}m$, $90\sim125{\mu}m$, $75\sim90{\mu}m$, $<75{\mu}m$. The sediment extract was analyzed water quality constituents, including chemical oxygen demand(COD), total nitrogen(T-N), total phosphorus(T-P), heavy metals and particle size distribution. The results indicate that most of particle size ranges of the bridge road sediments was $125\sim425{\mu}m$, and portion of $<75{\mu}m$ was low. But most of the pollutants are associated with the finer fractions of the load sediments. As the results of analysis, the range and average values of COD, T-N, T-P, Fe, Cu, Cr, and Pb were $177\sim198.8$ mg/kg(77.6 mg/kg), $23\sim200$ mg/kg(83 mg/kg), T-P $18\sim215$ mg/kg(129 mg/kg), and $1,508\sim5,612$ mg/kg(3,835 mg/kg), $9.2\sim69.3$ mg/kg(49 mg/kg), $19.1\sim662.2$ mg/kg(214 mg/kg), and $28.4\sim251.4$ mg/kg(114 mg/kg), respectively. The relationship between sediment size and pollutants concentration have an inverse proportion. The removal of road sediments with frequently could be reduced the significant nonpoint pollutant load, because of the bridge road sediment contains considerable micro-particles and heavy metals.

A Study on the Nursing Needs and Satisfactions of Early Postpartum Women (초기 산욕부의 간호요구도와 만족도에 관한 연구)

  • Yoo, Youn-Ja;Lee, Eun-Ju
    • Women's Health Nursing
    • /
    • v.5 no.3
    • /
    • pp.389-409
    • /
    • 1999
  • This study was carried out to identify the differences between nursing needs and levels of satisfaction of postpartum women during the early postpartum period. The goal of this study was to obtain needed to develope the nursing quality for postpartum women. The subjects were 87 postpartum women who had vaginal delivery at 2 general hospital and 2 maternity hospital in the Ulsan City. The period for the data collection was from June 1 to 29, 1999. The data was gathered using an 98 items questionnaire which was a modified version of a questionnaire the developed by Y. J. Chun. Results found are as follows : 1. The general characteristics of the subjects : The majority of subjects were 25-29 yrs. (57.5%), high school and college graduates(96.5%), unemployed(75.9%), middle ranged economics(93.1%), had no religion(43.7%), male baby(52.9%), birth weight 3-3.5Kg(49.4%), wanted pregnancy(96.6%), no abortion history(50.6%), had antenatal care(89.7%), had prenatal education(32.2%), postnatal education(42.5%), intended breast feeding (46.0%), had resonable self confidence about self(20.7%), infant care(36.8%) and nuclear family pattern(82.3%). 2. The level of nursing needs of overall nursing care(3.93) and the levels of satisfaction(3.86) was relatively high. The nursing needs by category of nursing care, the highest need was in the emotional and psychological care(4.09), and the lowest need was in physical need(3.73). The satisfactions by category of nursing care, the highest satisfaction was in emotional and psychological care(4.11) and the lowest satisfaction was in education in self care(3.64). The significant differences between nursing needs and satisfactions were found on education in infant care(p=.005), and education in self care(p=.020). 3. Among items of physical care, 'accurate medication and treatment(4.21)', 'control of postpartum hemorrhage(4.13)', 'pain control and care of episiotomy wound (4.12)' and 'regular observation of postpartum conditions(4.09)' showed high nursing needs. 'Accurate medication and treatment(4.31)', 'regular observation of postpartum condition(4.24)', 'control of postpartum hemorrhage(4.22)' and 'pain control and care of episiotomy wound(4.12)' showed high satisfaction levels. 4. Among items of emotional and psychological care, 'personal treatment(4.32)', kind and faithful care(4.30)', 'detailed explanation on the treatment or nursing care(4.25)', 'adequate draping during the care and treatment(4.23)' and detailed explanation on a doubt(4.13)', showed high nursing needs, 'personal treatment(4.52)', 'kind and faithful care(4.45)', 'detailed explanation on a doubt(4.24)', 'detailed explanation on the treatment or nursing care(4.21)' and 'adequate draping during the care and treatment(4.18)' showed high satisfaction of nursing care. Difference between the level of nursing needs and satisfaction was significant except item of 'early contacts with their baby and breast feeding'. 5. Among items of environmental care, the highest level of need and satisfaction were on the items of 'neat bedding and clothes(4.05, 4.21)' and 'room cleansing or care of room(4.01, 4.28)'. Differences between the level of nursing care and satisfaction were 'room cleansing of care of room'. 6. Among items of educational needs on self care, 'sitz bath method(4.22)', 'high risk symptoms to immediate clinic visits(4.13)', 'the timing of tub bath(4.05)' and 'good secretion of breast milk(4.03)', showed high nursing needs, 'sitz bath method(4.22)' showed high satisfaction of nursing care. Differences between the level of nursing care and satisfaction were 'the timing of hair shampoo', 'the timing of tub bath', ' the method of pad change', 'postpartum exercise', 'good secretion of breast milk', 'maintenance of breast figure', 'contraindicated drugs in postpartum women', 'kegel exercise' and 'breast self examination'. 7. Among items of educational needs on infant care, 'immunization of infants(4.36)', 'symptoms of sickness to immediate clinic visits(4.28)'. 'safety and emergency care(4.28)', 'umbilical care(4.26)', 'feeding times and intervals(4.24)', 'normal growth and development of infant(4.24)' and 'infection control(4.22)', showed high level of nursing care, 'immunization of infants(4.21)', 'feeding times and intervals(4.17)', were high satisfaction items showed significant differences between the level of nursing care and satisfaction. 8. Relationship between nursing needs and levels of satisfaction among postpartum women were as follows : 1) Physical area : There were no significant differences in the level of nursing needs, but satisfaction levels were significantly different among 'working mothers', 'baby's weights', 'baby's sex', 'planning of feeding' and 'routes of receiving postpartum informations'. 2) Emotional and psychological area : The level of nursing needs were significantly different in the area of 'confidence in self care'. Satisfaction levels were significantly different among 'baby's sex', 'baby's weights', 'the confidence of infant care' and 'working mother'. 3) Environment area : There were on significant differences in the level of nursing needs, but satisfaction levels were significantly different among 'maternal age' and 'baby's weights'. 4) Education in self care : The level of nursing needs were significantly different among 'parity history' and 'type of family formation'. Satisfaction levels were significantly different among 'working mother', 'baby's sex', 'antenatal care', 'postpartum education', 'planning of feeding', 'routes of receiving postpartum informations'. 5) Education in infant care area : The level of nursing needs were significantly different among 'parity history'. Satisfaction levels were significantly different among 'baby's sex', 'receiving postpartum education or not' and 'working mother'.

  • PDF

Vertical Ozone Distribution over Seoul: Ozonesonde Measurements During June 6~9, 2003 (서울지역 연직 오존 분포: 2003년 6월 6~9일 오존존데 관측)

  • Hwang, Mi-Kyoung;Kim, Yoo-Keun;Oh, In-Bo;Song, Sang-Keun;Lim, Yun-Kyu
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.24 no.2
    • /
    • pp.196-205
    • /
    • 2008
  • Variability in vertical ozone and meteorological profiles was measured by 2Z electrochemical concentration cells (ECC) ozonesonde at Bangyi in Seoul ($37.52^{\circ}N$, $127.13^{\circ}E$) during June $6{\sim}9$, 2003 in odor to identify the vertical distribution of ozone and its relationship with the lower-atmospheric structure resulted in the high ozone concentrations near the surface. The eight profiles obtained in the early morning and the late afternoon during the study period clearly showed that the substantial change of ozone concentrations in lower atmosphere(${\sim}5\;km$), indicating that it is tightly coupled to the variation of the planetary boundary layer (PBL) structure as well as the background synoptic flow. All profiles observed early in the morning showed very low ozone concentrations near the surface with strong vertical gradients in the nocturnal stable boundary layer due to the photochemical ozone loss caused by surface NO titration under very weak vertical mixing. On the other hand, relatively uniform ozone profiles in the developed mixing layer and the ozone peaks in the upper PBL, were observed in the late afternoon. It was noted that a significant increase in ozone concentrations in the lower atmosphere occurred with the corresponding decrease of the mixing height in the late afternoon on June 8. Ozone in upper layer did not vertically vary much compared to that in PBL but changed significantly on June 6 that was closely associated with the variation of synoptic flows. Interestingly, heavily polluted ozone layers aloft (a maximum value of 115 ppb around 2 km) were formed early in the morning on 6 through 7 June under dominant westerly synoptic flows. This indicates the effects of the transport of pollutants on regional scale and consequently can give a rise to increase the surface ozone concentration by downward mixing processes enhanced in the afternoon.