• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.339-346
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• 1999

This experiment was carried out to determine harvest date and cultivar effects on the agronomic characteristics, forage yield, and quality of fall sown oat (Avena sativa L.) at the forage experimental field, College of Agriculture and Life Sciences, Seoul National University, Suweon from August to November 1993. The experiment was arranged in a split plot design with three replications. The main plots were consisted of the harvesting dates, suchas early (11 October), mid(21 October), and late(1 November), the subplots were consisted of different maturities of oat cultivars, such as 'West', 'Cayuse' and 'Magnum'. The first heading date of an early maturing culivar, West, was observed on 10 October, and the heading increased up to 30% at the late harvesting date. The average dry matter (DM) content of oat cultivars increased significantly from 12.8 to 15.9% as the growing stage progressed(p<0.01). The average dry matter percentage of West, Cayuse, and Magnum was 15.4, 13.4, and 13.5%, respectively. The crude protein (CP) content of oat cultivars decreased significantly from 20.1 to 13.3% as the harvesting date was delayed(p<0.01), and the CP contents of midseason and late maturing cultivars, Cayuse and Magnum, respectively, were significantly higher than that of an early maturing cultivar West (p<0.01). The mid harvesting date showed the highest acid detergent fiber(ADF) and neutral detergent fiber (NDF) contents than the other harvesting dates, and an early maturing cultivar West had higher ADF and NDF contents than the midseason and late maturing cultivars, Cayuse and Magnum, respectively. The in vitro dry matter digestibility(IVDMD) of oat cultivar West decreased as the harvesting date was delayed, but that of Cayuse and Magnum decreased only by the mid harvesting date. Cayuse and Magnum showed 3~4% higher digestibility than West. The correlation coefficient between IVDMD and ADF content was -0.86. The average dry matter yield of oat cultivars increased from 2,901 to 5,901kg/ha as the harvesting date was delayed(p<0.01), but no significant difference was found among oat cultivars. The corrdelation coefficient between DM yield and gorwing degree days(GDD) was +0.86. The results of this study indicate that a delay in harvesting date would be recommendable for the increase of dry matter yield when fall-sown oat is grown. Especially, the DM yield of the midseason and late maturing cultivars, Cayuse and Magnum, respectively, can be increased without much change of forage quality although the harvesting date are delayed.

• Radiation Oncology Journal
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• v.26 no.3
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• pp.160-165
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• 2008

Purpose: In cases of locally advanced non-small cell lung cancer (NSCLC), concurrent chemoradiotherapy(CCRT) is the leading therapeutic modality. However, much controversy exists about the chemotherapeutic regimens and radiation methods. Materials and Methods: During concurrent chemoradiotherapy, three or four cycles of gemcitabine ($500\;mg/m^2$) and cisplatin ($30\;mg/m^2$) were administered every two weeks while 50.4 Gy of irradiation was administered in 28 fractions (once/day, 5 treatment days/week) to the tumor site, mediastinum, and the involved lymph node region. In addition, a booster irradiation dose of 18 Gy in 10 fractions was administered to the primary tumor site unless the disease progressed. Two or three cycles of consolidation chemotherapy were performed with gemcitabine ($1,200\;mg/m^2$, $1^{st}$ and 8th day) and cisplatin ($60\;mg/m^2$) every three weeks. Results: A total of 29 patients were evaluable for modality response. Response and treatment toxicities were assessed after concurrent chemoradiotherapy and consolidation chemotherapy, respectively. One patient (4%) achieved a complete response; whereas 20 patients (69%) achieved a partial response after concurrent chemoradiotherapy. Following the consolidation chemotherapy, three patients (10.3%) achieved complete responses and 21 patients (72.4%) achieved partial responses. The median follow-up period was 20 months (range $3{\sim}39$ months) and the median survival time was 16 months (95% CI; $2.4{\sim}39.2$ months). The survival rates in one, two, and three years after the completion of treatment were 62.7%, 43.9%, and 20%, respectively. Complications associated to this treatment modality included grade 3 or 4 esophagitis, which occurred in 15 patients (51.7%). In addition, an incidence of 24% for grade 3 and 14% for grade 4 neutropenia. Lastly, grade 2 radiation pneumonitis occurred in 6 patients (22%). Conclusion: The response rate and survival time of concurrent chemoradiotherapy with biweekly gemcitabine ($500\;mg/m^2$) and cisplatin ($30\;mg/m^2$) were encouraging in patients with locally advanced NSCLC. However, treatment related toxicities were significant, indicating that further modification of therapy seems to be warranted.

• Radiation Oncology Journal
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• v.4 no.1
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• pp.35-43
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• 1986

Study patients with head and neck carcinoma were studied retrospectively to assess the impact of treatment on survival and local control rate by stage in the Dept of Radiation Therapy, Korea University Hae Wha Hospital between March 1981 and March 1986. Prior to definite radiotherapy, patients were evaluated by physical examination and radiologic studies including chest, laryngogram and CT scan and then these patients were grouped according to the American Joint Committee (AJC) staging system. They were treated with RT alone or postoperative irradiation to the dose of 7,200 cGy/8 weeks and 6,000 cGy/7 weeks respectively. The results were obtained and as follows; 1. Overall male to female sex ratio was 3.6:1. The peak age of patients with head and neck cancer was 6th decade. 2. In all patients treated by RT, the ratio of squamous cell 1 carcinoma to non-squamous cell carcinoma was 3.5:1 (60/77 patients). 3. The incidence according to the anatomic site of primary tumor was 22 cases in the larynx, 12 cases in PNS, 7 cases in nasopharynx, 6 cases in oropharynx, and 3 cases in hypopharynx. 4. According to AJC staging system,4 cases were Stage 1,7 in Stage II, 19 in Stage III and 27 in Stage IV. 5. The overall incidence of cervical lymph node metastases was $43\%$ and subdigatric and submaxillary triangle lymph nodes were the most frequent site of metastases. 6. Local control was achieved in $48\%$ of patients treated by radio-therapy. 7. The lung was the most common site for distant metastases, comprising 4 cases among 7 cases in which distant metastases occured. 8. The overall estimated 5-year survival rate was $43\%$ in the head and neck cancer treated with radiotherapy by life-table analysis.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.163-168
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• 2009

Purpose: This study was a retrospective evaluation of the efficacy of stereotactic radiosurgery (SRS) in patients with >4 metastases to the brain. Materials and Methods: Between January 2004 and December 2006, 68 patients with $\geq$4 multiple brain metastases were included and reviewed retrospectively. Twenty-nine patients received SRS and 39 patients received whole brain radiotherapy (WBRT). Patients with small cell lung cancers and melanomas were excluded. The primary lesions were non-small cell lung cancer (69.0%) and breast cancer (13.8%) in the SRS group and non-small cell lung cancer (64.1%), breast cancer (15.4%), colorectal cancer (12.8%), esophageal cancer (5.1%) in the WBRT group. SRS involved gamma-knife radiosurgery and delivered 10~20 Gy (median, 16 Gy) in a single fraction with a 50% marginal dose. WBRT was delivered daily in 3 Gy fractions, for a total of 30 Gy. After completion of treatment, a follow-up brain MRI or a contrast-enhanced brain CT was reviewed. The overall survival and intracranial progression-free survival were compared in each group. Results: The median follow-up period was 5 months (range, 2~19 months) in the SRS group and 6 months (range, 4~23 months) in the WBRT group. The mean number of metastatic lesions in the SRS and WBRT groups was 6 and 5, respectively. The intracranial progression-free survival and overall survival in the SRS group was 5.1 and 5.6 months, respectively, in comparison to 6.1 and 7.2 months, respectively, in the WBRT group. Conclusion: SRS was less effective than WBRT in the treatment of patients with >4 metastases to the brain.

• Radiation Oncology Journal
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• v.23 no.2
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• pp.85-91
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• 2005

Purpose : This study was conducted to analyze treatment outcome and prognostic significance of World Health Organization (WHO)-defined thymic epithelial tumor (TET) subtype and to assess optimal radiation target volume in patients receiving surgery and adjuvant radiation therapy with TET. Materials and Methods: The record of 160 patients with TET, who received surgical resection at the Samsung medical Center, from December 1994 to June 2004, were reviewed. 99 patients were treated with postoperative radiation therapy (PORT). PORT was recommended when patients had more than one findings among suspicious Incomplete resection or positive resection margin or Wasaoka stage $II\~IV$ or WHO type $B2\~C$. PORT peformed to primary tumor bed only with a mean dose of 54 Gy. The prognostic factor and pattern of failure were analyzed retrospectively. Results : The overall survival rate at 5 years was $87.3\%$. Age (more than 60 years $77.8\%$, less than 60 years $91.1\%$; p=0.03), Wasaoka stage (I $92.2\%$, II $95.4\%$, III $82.1\%$, IV $57.5\%$; p=0.001), WHO tumor type (A-Bl $96.0\%$, B2-C $82.3\%$; p=0.001), Extent of resection (R0 resection $92.3\%$, R1 or 2 resection $72.6\%$, p=0.001) were the prognostic factors according to univariate analysis. But WHO tumor type was the only significant prognostic factor according to multivariate analysis. Recurrence was observed in 5 patients of 71 Masoka stage I-III patients who received grossly complete tumor removal (R0, R1 resection) and PORT to primary tumor bed. Mediastinal recurrence was observed In only one patients. There were no recurrence within irradiation field. Conclusion : WHO tumor type was the important prognostic factor to predict survival of patients with TET. This study suggest that PORT to only primary tumor bed was optimal. To avoid pleura- or pericardium-based recurrence, further study of effective chemotherapy should be investigated.

• Journal of Broadcast Engineering
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• v.24 no.1
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• pp.118-131
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• 2019

In order to provide 8K UHD contents of terrestrial broadcasting with a large capacity, the terrestrial broadcasting system has various problems such as limited bandwidth and so on. To solve these problems, UHD contents transmission technology has been actively studied, and an 8K UHD broadcasting system using terrestrial broadcasting network and communication network has been proposed. The proposed technique is to solve the limited bandwidth problem of terrestrial broadcasting network by segmenting 8K UHD contents and transmitting them to heterogeneous networks through hierarchical separation. Through the terrestrial broadcasting network, the base layer corresponding to FHD and the additional enhancement layer data for 4K UHD are transmitted, and the additional enhancement layer data corresponding to 8K UHD is transmitted through the communication network. When 8K UHD contents are provided in such a way, user can receive up to 4K UHD broadcasting by terrestrial channels, and also can receive up to 8K UHD additional communication networks. However, in order to transmit the 4K UHD contents within the allocated bit rate of the domestic terrestrial UHD broadcasting, the compression rate is increased, so a certain level of image deterioration occurs inevitably. Due to the nature of UHD contents, video quality should be considered as a top priority over other factors, so that video quality should be guaranteed even within a limited bit rate. This requires packet scheduling of content generators in the broadcasting system. Since the multiplexer sends out the packets received from the content generator in order, it is very important to make the transmission time and the transmission rate of the process from the content generator to the multiplexer constant and accurate. Therefore, we propose a variable transmission scheduler between the content generator and the multiplexer to guarantee the image quality of a certain level of UHD contents in this paper.

• Radiation Oncology Journal
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• v.18 no.1
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• pp.32-39
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• 2000

Purpose :The incidence of adenocarcinoma of the uterine cervix is low. Traditionally, Low Dose Rate (LDR) brachytherapy has been used as a standard modality in the treatment for patients with carcinoma of the uterine cervix. The purpose of this report is to evaluate the effects of the High dose rate (HDR) brachytherapy in the patients with adenocarcinoma of the uterine cervix compared with the LDR. : From January 1971 to December 1992, 106 patients of adenocarcinoma of uterine cervix were treated with radiation therapy in the Department of Radiation Oncology, Yonsei University with curative intent. LDR brachytherapy was carried out on 35 patients and 71 patients were treated with HDR brachytherapy. In LDR Group, 8 patients were in stage I, 18 in stage II and 9 in stage III. External radiation therapy was delivered with 10 MV X-ray, daily 2 Gy fractionation, total dose 40$\~$46Gy (median 48 Gy). And LDR Radium intracavitary irradiation was peformed with Henschke applicator, 22$\~$59 Gy to point A (median 43 Gy). In HDR Group, there were 16 patients in stage 1, 38 in stage II and 17 in stage III. The total dose of external radiation was 40$\~$61 Gy(median 45 Gy), daily 1.8$\~$2.0 Gy. HDR Co-60 intracavitary irradiation was peformed with RALS (Remote Afterloading System), 30 $\~$ 57 Gy(median 39 Gy) to point A, 3 times a week, 3 Gy per fraction. Conclusion : The 5-year overall survival rate in LDR Group was 72.9$\%$, 61.9$\%$, 45.0$\%$ in stage I, II, III, respectively and corresponding figures for HDR were 87.1$\%$, 58.3$\%$, 41.2$\%$, respectively (p>0.05). There was no statistical difference in terms of the 5-year overall survival rate between HDR Group and LDR Group in adenocarcinoma of the uterine cervix. There was 11$\%$ of late complication rates in LDR Group and 27$\%$ in HDR Group. There were no prognostic factors compared HDR with LDR group. The incidence of the late complication rate in HDR Group stage II, III was higher than that in LDR Group(16.7$\%$ vs. 31.6$\%$ in stage II, 11.1$\%$ vs. 35.3$\%$ In stage III, p>0.05). Although the incidence of radiation induced late complication rate was higher in HDR Group stage II and III patients than that in the LDR Group, statistical significance was not detected and within acceptable level. Conclusion : There was no difference in terms of 5-year survival rate and failure pattern in the patients with adenocarcinoma of the uterine cervix treated with HDR and LDR brachytherapy. Even late complication rates were higher in the HDR group It was an acceptable range. This retrospective study suggests that HDR brachytherapy seems to replace the LDR brachytherapy in the adenocarcinoma of the uterine cervix. However, further studies will be required to refine the dose rate effects.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.510-514
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• 2007

This study was carried on cool and RT(room temperature) storage of unhulled rice. In RT storage of an analysis of coefficient relation, high significant positive coefficients were observed in toyo index and breakdown, setback and protein content. high significant negative coefficients were showed setback and breakdown, breakdown and protein content. In cool storage of an analysis of coefficient relation, high significant positive coefficients were observed in toyo index and amylose content and gelatinization start temperature and protein content and high significant negative coefficients were showed toyo index and whiteness, toyo index and gelatinization start temperature, gelatinization start temperature and amylose content. In RT storage of a path coefficient analysis, a highest positive direct influence was observed in amylose content and a highest negative direct influence was protein content. Positive indirect influence was high revealed breakdown and protein content and negative indirect influence was gelatinization start temperature and Mg/K ratio. In cool storage of a path coefficient analysis, a highest positive direct influence was whiteness and a highest positive indirect influence was gelatinization start temperature. Positive indirect influence was high revealed gelatinization start temperature and amylose content, negative indirect influence was whiteness and gelatinization start temperature. In RT storage of Multiple regression equation of Toyo index based on physicochemical properties of unhulled rice, a highest coefficient of determination was revealed among five facters of whiteness, protein content, Mg/K ratio, amylose content and gelatinization start temperature. In cool storage of Multiple regression equation of toyo index based on physicochemical properties of unhulled rice, highest coefficient of determination was revealed among five facters of moisture content, amylose content, gelatinization start temperature, breakdown and setback.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.49-60
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• 2002

Receive dynamic focusing with an array transducer can provide near optimum resolution only in the vicinity of transmit focal depth. A customary method to increase the depth of field is to combine several beams with different focal depths, with an accompanying decrease in the frame rate. In this Paper. we Present a simultaneous multiple transmit focusing method in which chirp signals focused at different depths are transmitted at the same time. These chirp signals are mutually orthogonal in a sense that the autocorrelation function of each signal has a narrow mainlobe width and low sidelobe levels. and the crossorelation function of any Pair of the signals has values smaller than the sidelobe levels of each autocorrelation function. This means that each chirp signal can be separated from the combined received signals and compressed into a short pulse. which is then individually focused on a separate receive beamformer. Next. the individually focused beams are combined to form a frame of image. Theoretically, any two chirp signals defined over two nonoverlapped frequency bands are mutually orthogonal In the present work. however, a tractional overlap of adjacent frequency bands is permitted to design more chirp signals within a given transducer bandwidth. The elevation of the rosscorrelation values due to the frequency overlap could be reduced by alternating the direction of frequency sweep of the adjacent chirp signals We also observe that the Proposed method provides better images when the low frequency chirp is focused at a near Point and the high frequency chirp at a far point along the depth. better lateral resolution is obtained at the far field with reasonable SNR due to the SNR gain in Pulse compression Imaging .

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.1
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• pp.17-27
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• 2023

Weeds are one of the factors that reduce crop yield through nutrient and photosynthetic competition. Quantification of weed density are an important part of making accurate decisions for precision weeding. In this study, we tried to quantify the density of weeds in images of maize fields taken by unmanned aerial vehicle (UAV). UAV image data collection took place in maize fields from May 17 to June 4, 2021, when maize was in its early growth stage. UAV images were labeled with pixels from maize and those without and the cropped to be used as the input data of the semantic segmentation network for the maize detection model. We trained a model to separate maize from background using the deep learning segmentation networks DeepLabV3+, U-Net, Linknet, and FPN. All four models showed pixel accuracy of 0.97, and the mIOU score was 0.76 and 0.74 in DeepLabV3+ and U-Net, higher than 0.69 for Linknet and FPN. Weed density was calculated as the difference between the green area classified as ExGR (Excess green-Excess red) and the maize area predicted by the model. Each image evaluated for weed density was recombined to quantify and visualize the distribution and density of weeds in a wide range of maize fields. We propose a method to quantify weed density for accurate weeding by effectively separating weeds, maize, and background from UAV images of maize fields.