• Journal of Biosystems Engineering
• /
• v.23 no.5
• /
• pp.439-444
• /
• 1998

Effects of the number of spans, orientation and latitude on the transmissivities of direct and diffuse solar radiation in multispan glasshouse were analyzed using a computer simulation model (Kim and Lee, 1997). The number of spans did not affect the transmissivity of diffuse solar radiation, ranging 60∼61%. The transmissivities of direct solar radiation were 55∼64% for E-W orientation and 47∼70% for N-S orientation in ten multispan glasshouse. There was no effect of the latitude on the transmissivity of direct solar radiation in domestic regions. Differences in the transmissivity of direct solar radiation between single-span and multispan glasshouse were significant for E-W orientation during winter season; however, those were relatively small for N-S orientation throughout the year. Transmissivity of direct solar radiation decreased with the increasing number of spans for E-W glasshouse, whereas those for N-S glasshouse was hardly affected by the number of spans.

• Solar Energy
• /
• v.9 no.3
• /
• pp.13-24
• /
• 1989

Direct and diffuse components of solar radiation were measured inside and outside a single-span plastic greenhouse. To analyze the direct solar radiation inside the plastic greenhouse, the cross-section of the greenhouse was assumed to be circular. Then the direct solar radiation transmitted into the greenhouse was calculated theoretically, and compared with the experimental measurements. The results are summarized as follows: (1) The transmissivities of total solar radiation were about 65% on cloudy days and 50% on clear days. For cloudy days, the transmissivity of the total solar radiation was regarded as the transmissivity of sky diffuse radiation. (2) The ratio of the inside effective scattered component of direct solar radiation to the diffuse radiation was 60-65%. (3) It appeared that the seasonal variation of the transmissivity of total solar radiation was adversely affected by the transmissivity of direct solar radiation and the effective scattered coefficient. But the effect of the transmissivity of direct solar radiation was dominant factor. (4) Computer simulation showed that the inside direct solar radiation was decreased as the floor of the plastic greenhouse was higher. (5) The predicted value of the inside direct solar radiation was 3.3% to 29.0% higher than the measured value.

• Journal of Bio-Environment Control
• /
• v.6 no.3
• /
• pp.176-182
• /
• 1997

A simulation model for the analysis of the transmissivity of direct and diffuse solar radiation In glasshouse was developed. This model would be applicable to investigate the influences of time of year, orientation and slope of glasshouse, dimensions of the frames used, and latitude of the site on the transmissivity of direct and diffuse solar radiation in single-span or multispan glasshouse. The transmissivity of diffuse solar radiation was 60.4％ for the single-span glass-house. It was independent of both orientation and time of year, During the winter season, the transmissivity of direct solar radiation was 67~69％ for the E-W orientation single-span glasshouse, which was 14~16％ higher than that for the S-N orientation. Oppositely the transmissivity of direct solar radiation for the S-N orientation was higher than that for the E-W orientation. during the autumn season. There was no influence of the latitude In the country on the transmissivity of direct solar radiation.

• Journal of the Korean Solar Energy Society
• /
• v.34 no.1
• /
• pp.105-116
• /
• 2014

The objective of this study was to compare and analyze of radiation environment between downtown and suburban area by observation of short, diffuse and long-wave radiation during summer season. The followings are main results from this study. 1) The trends of long-wave radiation is increasing from May to August and the variation of daily range is decreased. It is confirmed that the temperature was closely relevant to long wave radiation. 2) During observation period, suburban area is higher than downtown the value of direct solar radiation. 3) There are much direct solar radiation in suburban area than downtown. But, it was measured much more horizontal solar radiation at the downtown area. From the this result, we can conclude that diffuse radiation play a important role at horizontal solar radiation.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.23 no.2
• /
• pp.134-140
• /
• 2021

Global solar radiation consists of direct and diffuse radiations. Both components are necessary for not only atmospheric science and solar energy domains but also agricultural applications. In this study, the data of direct and diffuse radiations are uploaded to Github. It was observed in Naju during May 2019 to November 2020. Using this data, the previous empirical equations using the relation between clearness index and diffuse ratio were validated. All coefficients of determination (R²) and RMSE were similar as 0.79~0.80 and 0.13~0.15. However, to get the lower RMSE, other non-linear approaches will be required with more observation data.

• Radiation Oncology Journal
• /
• v.25 no.4
• /
• pp.278-282
• /
• 2007

Purpose: Diffuse pigmented villonodular synovitis (PVNS) is an uncommon aggressive synovial proliferative disorder of unknown etiology affecting the joint linings. Though a histologically benign inflammatory process, because of its aggressive growth with bone destruction or recurrence, it is frequently suggested to occur as a low malignant neoplasm. Optimal treatment is surgery, but the local recurrence rate after radical synovectomy for diffuse PVNS is relatively high due to the infiltrative growth pattern. External beam radiotherapy with moderate doses or intra-articular instillation of radioactive isotopes may improve the likelihood of local control and long-term function in patients with incompletely resected or recurrent diffuse PVNS. I report one case of diffuse PVNS of the right knee joint treated with arthroscopic synovectomy and external beam radiotherapy is presented.

• Radiation Oncology Journal
• /
• v.35 no.4
• /
• pp.317-324
• /
• 2017

Purpose: This study evaluated outcomes of radiotherapy (RT) after chemotherapy in limited-stage head-and-neck diffuse large B-cell lymphoma (DLBCL). Materials and Methods: Eighty patients who were treated for limited-stage head-and-neck DLBCL with CHOP (n = 43) or R-CHOP (n = 37), were analyzed. After chemotherapy, RT was administered to the extended field (n = 60) or the involved field (n = 16), or the involved site (n = 4). The median dose of RT ranged from 36 Gy in case of those with a complete response, to 45-60 Gy in those with a partial response. Results: In all patients, the 5-year overall survival (OS) and disease-free survival (DFS) rates were 83.9% and 80.1%, respectively. In comparison with the CHOP regimen, the R-CHOP regimen showed a better 5-year DFS (86.5% vs. 73.9%, p = 0.027) and a lower rate of treatment failures (25.6% vs. 8.1%, p = 0.040). The volume (p = 0.047) and dose of RT (p < 0.001) were significantly reduced in patients treated with R-CHOP compared to that in those treated with CHOP. Conclusion: The outcomes of RT after chemotherapy with R-CHOP were better than those of CHOP regimen for limited-stage head-and-neck DLBCL. In patients treated with R-CHOP, a reduced RT dose and volume might be feasible without increasing treatment failures.

• Journal of The Korean Astronomical Society
• /
• v.22 no.2
• /
• pp.141-160
• /
• 1989

In order to derive time dependence of the atmospheric diffuse light, which consists of the airglow continuum emission and diffusely scattered radiations of the intergrated starlight, the diffuse Galactic light, and the zodiacal light, we have analyzed the meridian scan observations of the sky brightness at $5,080\;{\AA}$ and $5,300\;{\AA}$. Amplitude of the time-variation becomes larger for lower elevation, and maximum amplitude is found to be about $50\;S_{10}(V)_{G2V}$ at elevation $10^{\circ}$. The atmospheric diffuse radiation attains maximum brightness at around midnight, and afterward it decreases slowly with time. The time-variations for the two wavelengths are similar to each other. The observed brightness distribution of the diffuse light along the zenith distance is fitted to an empirical relation of two parameters. By making the two parameters time-dependent, we describe the spatial and time variations of the atmospheric diffuse light. This enables us to make time dependent correction for the atmospheric diffuse component in the reduction of zodiacal light brightness.

• Radiation Oncology Journal
• /
• v.20 no.4
• /
• pp.303-308
• /
• 2002

Purpose : To determine the optimal radiation dose in a localized non-Hodgkin's lymphoma of the head and neck in the treatment setting for combined chemoradiotherapy. Materials an Methods :Fifty-three patients with stage I and II diffuse large ceil non-Hodgkin's lymphoma of the head and neck, who were treated with combined chemoradiotherapy between 1985 and 1998 were retrospectively reviewed. The median age was 49 years, and the male-to-female ratio was approximately 1.6. Twenty-seven patients had stage 1 disease and 26 had stage II. Twenty-three patients had bulky tumors $(\geq5\;cm)$ and 30 had non-bulky tumors (<5 cm). The primary tumors arose mainly from an extranodal organ $(70\%)$, most cases involving Waldeyer's ring $(90\%)$. All patients except one were initially treated with $3\~6$ cycles of chemotherapy, which was followed by radiotherapy. Radiation was delivered either to the primary tumor area alone $(9\%)$ or to the primary tumor area plus the bilateral neck nodes $(91\%)$ with a minimum dose of 30 Gy $(range\;30\~60\;Gy)$. The failure patterns according to the radiation field were analyzed, and the relationship between the dose and the in-field recurrence was evaluated. Results : The 10-year overall survival and the 10-year disease free survival rates were similar at $75\%\;and\;76\%$, respectively. A complete response (CR) after chemotherapy was achieved in 44 patients $(83\%)$. Subsequent radiotherapy showed a CR in all patients. Twelve patients $(23\%)$ had a relapse of the lymphoma after the initial treatment. Two of these patients had a recurrence inside the radiation field. No clear dose response relationship was observed and no significant prognostic factors for the in-field recurrences were identified because of the small number of in-field recurrences. However, for patients with tumors <5 cm in diameter, there were no in-field recurrences after a radiation dose 30 Gy. The 2 in-field recurrences encountered occurred in patients with a tumor $\geq5\;cm$. Conclusion .A dose of 30 Gy is sufficient for local control in patients with a non-bulky (<5 cm), localized, diffuse large cell non-Hodgkin's lymphoma when combined with chemotherapy. An additional boost dose in the primary site is recommended for patients with bulky tumors $(\geq5\;cm)$.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.11a
• /
• pp.595-598
• /
• 2005

The thermal performance of glass evacuated tube solar collectors are numerically and experimentally investigated. Four different shapes of solar collectors are considered and the performances of these solar collectors are compared. Dealing with a single collector tube, the effects of not only the shapes of the absorber tube but also the incidence angle of solar irradiation (beam radiation) on thermal performance of the collector are studied. However the solar irradiation consists of the beam radiation as well as the diffuse radiation. Also, the interference of solar irradiation and heat transfer interaction between the tubes exist in an actual solar collector. These effects are considered in this study experimentally and numerically the accuracy of the numerical model is verified by the experimental results. The result shows that the thermal performance of the absorber used a plate fin and U-tube is the best.