• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.32-49
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• 1998

For estimation of regional myocardial blood flow with O-15 water PET, a few modifications considering partial volume effect based on single compartment model have been proposed. In this study, we attempted to quantify the degree of heterogeneity and to show the effect of tissue flow heterogeneity on partition coefficient(${\lambda}$) and to find the relation between perfusable tissue index(PTI) and ${\lambda}$ by computer simulation using two modified models. We simulated tissue curves for the regions with homogeneous and heterogeneous blood flow over a various flow range(0.2-4.0ml/g/min). Simulated heterogeneous tissue composed of 4 subregions of the same or different size of block which have different homogeneous flow and different degree of slope of distribution of blood flow. We measured the index representing heterogeneity of distribution of blood flow for each heterogeneous tissue by the constitution heterogeneity(CH). For model I, we assumed that tissue recovery coefficient ($F_{MME}$) was the product of partial volume effect($F_{MMF}$) and PTI. Using model I, PTI, flow, and $F_{MM}$ were estimated. For model II, we assumed that partition coefficient was another variable which could represent tissue characteristics of heterogeneity of flow distribution. Using model II, PTI, flow and ${\lambda}$ were estimated. For the simulated tissue with homogeneous flow, both models gave exactly the same estimates, of three parameters. For the simulated tissue with heterogeneous flow distribution, in model I, flow and $F_{MM}$ were correctly estimated as CH was increased moderately. In model II, flow and ${\lambda}$ were decreased curvi-linearly as CH was increased. The degree of underestimation of ${\lambda}$ obtained using model II, was correlated with CH. The degree of underestimation of flow was dependent on the degree of underestimation of ${\lambda}$. PTI was somewhat overestimated and did not change according to CH. We conclude that estimated ${\lambda}$ reflect the degree of tissue heterogeneity of flow distribution. We could use the degree of underestimation of ${\lambda}$ to find the characteristic heterogeneity of tissue flow and use ${\lambda}$ to recover the underestimated flow.

• Tuberculosis and Respiratory Diseases
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• v.52 no.5
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• pp.506-518
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• 2002

Background : There have been several studies showing that angiotensin II and the angiotensin converting enzyme (ACE) contribute to the activation of fibroblast including the pulmonary fibrosis, and apoptosis of the alveolar epithelium in idiopathic intersititial pneumonia. This study was performed to identify the relationship between the serum angiotensin II, ACE and the pulmonary function test (PFT), the dyspnea score, and the cell fraction of the bronchoalveolar lavage fluid(BALF). Materials and Methods : Twenty three patients with idiopathic interstitial pneumonia from March, 1999 to October, 2001 at Gachon medical school were enrolled in this study. They were divided into IPF(UIP) (16) and NSIP (7) groups. Twelve of the idiopathic interstitial pneumonia patients (UIP : 5, NSIP : 7) were diagnosed by an open lung biopsy, 11 of IPF patients were diagnosed by the American Thoracic Society (ATS) diagnostic criteria. The PFT values, dyspnea score, serum ACE and angiotensin II were measured, and a bronchoscopy was performed to obtain the BALF. Results : Of all the patients, 7 were in the normal range and 14 showed an increase in the serum level of angiotensin II. In terms of the serum ACE level, 14 patients had an increased level. The DLCO% of the angiotensin II in increased group was significantly lower than the not-increased group (p=0.021). Other factors did not correlate with the serum ACE or the angiotensin II increased group and not-increased group. Conclusion : These results suggest that an increased angiotensin II serum level may be associated with increase in the of alveolar capillary block in the progression of pulmonary fibrosis in idiopathic interstitial pneumonia.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.219-226
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• 2006

The wastes (the needle leaves and branches) produced from thinning the forest were fermented under an anaerobic condition (pine silage) to utilize as a forage source of ruminants. An in situ trial was conducted with two ruminally fistulated Korean native cows by 4 replicates (2 bags per cow), and in vivo digestibility of pine silage was estimated with five Korean native steers by 5 replicates in incomplete double turn-over design. In order to investigate feed efficiency and carcass traits, forty eight Korean native bulls were assigned to four treatments (0%, 25%, 50%, 75% of pine silage) with a completely randomized design in 12 pens accommodating 4 animals per pen. The amounts of concentrate and roughage allowed to experimental animals were in the range of 2.5% and 0.6% of body weight, respectively. Animals had freely accessed to mineral block and water in stanchion barn.An in situ crude protein digestibility of the roughage sources when suspended for 48 hrs in the rumen was higher for feeding the pine silage than the rice straw, whereas NDF digestibility was vice versa. No differences between the treatments were observed in in vivo digestibilities of dry matter, crude protein and NDF. Daily body weight gain was significantly (P<0.01) higher for the pine silage substitutions compared with the rice straw feeding except for the 25% silage feeding. The pine silage feeding did not affect feed efficiency.In carcass traits, marbling score tended to be higher for the 50% pine silage treatment than the other treatments while back fat thickness tended to be the thinnest for the rice straw feeding. From these results, it may be recommended to substitute pine silage, as a forage source, for rice straw by 50 percent.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.277-282
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• 2017

This study was conducted to evaluate on agronomic characteristics, forage quality and dry matter (DM) yields of mugwort (Artemisia princeps Pamp.) collected different region at Seongju in Kyeongbuk from 2014 to 2015. The experiment was arranged in randomized complete block design with three replications. Mugwort was planted on $17^{th}$ March, 2014 and harvested on $13^{th}$ September, 2014 and on $25^{th}$ May and $9^{th}$ September, 2015. DM yields of Dalsung(1), Seongju B.(1), Dalsung(2) and Sajuarissuk were 17.3, 16.8, 16.7 and $16.7(MT\;ha^{-1})$, respectively and the DM yields of those were higher (p<0.05) than the other mugworts in 2014. In 2015, DM yields of Dalsung(1), Dalsung(2), Seongju B.(1), and Sajuarissuk were 19.5, 19.3, 18.4 and $18.4(MT\;ha^{-1})$, respectively and DM yields of those were higher (p<0.05) than the others. DDM(digestable dry matter) content of mugworts was a range of 56.4 to 60.8% and that of Sajabalssuk, 60.8% was the highest. Seongju B.(1) 58.8% was higher than Seongju B.(2) 56.4% but there were no difference among the Dalsung(1) 58.4%, Dalsung(2) 58.1%, Sajuarissuk 57.7% and Yeongcheon. The result of this study indicated that Dalsung(1), Dalsung(2), Sajuarissuk and Seongju B.(1) would be recommendable for forage production.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.1
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• pp.16-22
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• 2014

Purpose: The purpose of this study was to assess the marginal and mesial fitness of zirconia single copings and 3-unit fixed partial dentures (FPDs) manufactured with an identical model. Materials and Methods: An epoxy model in which the maxillary right 2nd premolar is lost and maxillary 1st premolar and 2nd molar are formed as abutments was manufactured and scanned by using a laser scanner. A ten units of zirconia single copings were manufactured for maxillary 1st premolar and 2nd molar, respectively and the same number of 3-unit FPDs were manufactured. For the measurements of fitness, the manufactured silicone replicas were divided into four parts and the fitness were measured by digital microscope at measurement points (P1, P2, P3, P4 and P5) of each plane. The measured gaps were classified into three categories: marginal gap (MG, P1), axial gap (AG, average of P2 and P3), occlusal gap (OG, average of P4 and P5). Results: The ranges of MG, AG and OG for single copings were 18.47 - 40.54 ${\mu}m$, 39.73 - 73.61 ${\mu}m$ and 116.90 - 134.69 ${\mu}m$, respectively. The ranges of MG, AG and OG for 3-unit FPDs were 45.95 - 87.44 ${\mu}m$, 23.78 - 57.00 ${\mu}m$ and 99.89 - 131.06 ${\mu}m$, respectively. Conclusion: The result of the study shows that the MGs for 3-unit FPDs were higher than those of single copings, though they are within the range of clinical acceptance, indicating that the use of more homogeneous zirconia block and modification of sintering processes are needed to ensure the prevention of increase of gap in 3-unit FPDs.

• Radiation Oncology Journal
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• v.14 no.3
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• pp.201-209
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• 1996

Purpose : To assess the efficacy of high dose rate - intracavitary radio-therapy (HDR-ICR) in the radiotherapy of FIGO stage IB squamous cell carcinoma of uterine cervix and to determine the optimum dose combination scheme of external radiotherapy and ICR to achieve acceptable local control without severe complication. Materials and Methods : One hundred and sixty two patients with FIGO stage Ib squamous cell carcinoma of uterine cervix who received definitive radiotherapy between May 1979 and December 1990 were retrospectively analyzed. All the patients received external radiotherapy combined with HDR-ICR. External dose of 40-46 Gy in 4.5-5 weeks was given to whole pelvis(median 45 Gy) and ICR dose of 30-39 Gy in 10-13 times was given to the point A. Midline shielding was done after 20-45 Gy of external radiotherapy(median 40 Gy) Summation of external dose Plus ICR dose to the point A range were 64.20-95.00 Gy. and mean was 83.94 Gy. We analyzed the local control rate, survival rate, and late complication rate. Rusults : Initial complete response rate was $99.4\%$ for all patients. Overall 5-year survival rate was $91.1\%$ and 5-year disease free survival rate was $90.9\%$. Local failure rate was $4.9\%$ and distant failure rate was $4.3\%$. Tumor size was the only significant prognostic factor. When tumor size greater than 3cm, 5-rear survival rate was $92.6\%$ and less than 3cm, that was $79.6\%$. Late complication rate was $23.5\%$ with $18.5\%$ of rectal complication and $4.9\%$ of bladder complication. Mean rectal dose summation of external midline dose plus ICR rectal point dose was lower in the patients without rectal complication(74.88 Gr) than those with rectal complication (78.87 Gy). Complication rate was increased with low rate of improvement of survival rate when summation of external midline dose plus point A or point R dose by ICR was greater than 70-75 Gy. Conclusion : The definitive radiation therapy using high dose rate ICR in FIGO stage IB uterine cervical cancer is effective treatment modality with good local control and survival rate without severe complication.

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.477-484
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• 2006

The purposes of this study were to compare the apical terminus width of simulated curved root canal prepared with three NiTi file systems used by undergraduates for evaluation the effects of flute angle and pitch or radial land on reducing screw-in effect and to determine more safe NiTi file system for inexperienced operators. Fifty inexperienced undergraduate students prepared 150 simulated curved root canals in resin blocks with three NiTi file systems ; ProFile$^{(R)}$, Hero Shaper$^{(R)}$, K3$^{TM}$. The electric motor set at a speed of 300 rpm and torque of 30 in a 16 : 1 reduction handpiece was used. The simulated root canal was prepared to ISO #25 sizes with each file system. The scanned images of pre- and post-instrumented canal of resin block were superimposed. To evaluate the screw-in effect of three NiTi file systems, apical terminus width of root canal was measured from superimposed images and statistical analysis was performed. There were significant differences in three NiTi flle systems. ProFile$^{(R)}$ had significantly smaller width than Hero Shaper$^{(R)}$ and K3$^{TM}$"" (P < 0.05), but no significant difference was observed between K3$^{TM}$ and Hero Shaper$^{(R)}$. Under the condition of this study, active file system (Hero SHaper$^{(R)}$, K3$^{TM}$) with variable pitch and helical angle had more screw-in effect than passive file system (ProFile$^{(R)}$) with constant pitch and helical angle. It seems that the radial lands play more important role in reducing screw-in effect.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.453-458
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• 2001

The Rural Development Administration (RDA) of Korea now operates a system called Rice Variety Selection Tests (RVST), which are now being implemented in eight Agricultural Research and Extension Services located in eight province RVST's objective is to provide accurate yield estimates and to select well-adapted varieties to each province. Systematic evaluation of entries included in RVST is a highly important task to select the best-adapted varieties to specific location and to observe the performance of entries across a wide range of test sites within a region. The rice yield data in RVST for ordinary transplanting in Kangwon province during 1997-2000 were analyzed. The experiments were carried out in three replications of a random complete block design with eleven entries across five locations. Additive Main effects and Multiplicative Interaction (AMMI) model was employed to examine the interaction between genotype and environment (G$\times$E) in the biplot form. It was found that genotype variability was as high as 66％, followed by G$\times$E interaction variability, 21％, and variability by environment, 13％. G$\times$E interaction was partitioned into two significant (P＜0.05) principal components. Pattern analysis was used for interpretation on G$\times$E interaction and adaptibility. Major determinants among the meteorological factors on G$\times$E matrix were canopy minimum temperature, minimum relative humidity, sunshine hours, precipitation and mean cloud amount. Odaebyeo, Obongbyeo and Jinbubyeo were relatively stable varieties in all the regions. Furthermore, the most adapted varieties in each region, in terms of productivity, were evaluated.

• Radiation Oncology Journal
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• v.24 no.1
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• pp.37-43
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• 2006

Purpose: We wanted to determine the clinical characteristics and prognosis according to the VEGF expression in stage II cervical carcinoma patients treated with definitive radiotherapy. Materials and Methods: We enrolled 31 patients who were diagnosed with cervical cancer from 1995 to 2003 at Samsung Medical Center and their paraffin block tissue samples were available for study. The median age of the patients was 65 years. The mean tumor size was 4.1 cm $(range:\;1.2{\sim}8.2cm)$. Seven patients (22.6%) were suspected of having pelvic lymph node metastasis. An external beam irradiation dose of 45-56.4 Gy was administered to the whole pelvis with a 15 MV linear accelerator, and an additional 24 Gy was given to point A by HDR intracavitary brachytherapy. VEGF staining was defined as positive when more than 10% of the tumor cells were stained. The median follow-up duration was 58 months. Results: A positive VEGF expression was observed in 21 patients (67.7%), There was no significant correlation between the VEGF expression and pelvic lymph node metastasis, tumor size and the response of radiotherapy. During follow-up, 7 patients had recurrence. The complete response rate was not significant between the VEGF(-) and VEGF(+) tumors. However, the VEGF(+) tumors showed a significantly higher recurrence rate in comparison with the VEGF(-) tumors (p=0.040), The three year disease-free survival rates were 100% and 66.7%, respectively, for patients with VEGF(-) or VEGF(+) tumor (p=0.047), Conclusion: The VEGF expression was a significant factor for recurrence and disease-free survival. However, the significance of the VEGF expression is still controversial because of the various definitions of VEGF expression and the mismatches of the clinical data in the previous studies.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.3-16
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• 2008

A Wireless Sensor Network (WSN for short) is a wireless network consisting of distributed small devices which are called sensor nodes or motes. Recently, there has been an extensive research on WSN and also on its security. For secure storage and secure transmission of the sensed information, sensor nodes should be equipped with cryptographic algorithms. Moreover, these algorithms should be efficiently implemented since sensor nodes are highly resource-constrained devices. There are already some existing algorithms applicable to sensor nodes, including public key ciphers such as TinyECC and standard block ciphers such as AES. Stream ciphers, however, are still to be analyzed, since they were only recently standardized in the eSTREAM project. In this paper, we implement over the MicaZ platform nine software-based stream ciphers out of the ten in the second and final phases of the eSTREAM project, and we evaluate their performance. Especially, we apply several optimization techniques to six ciphers including SOSEMANUK, Salsa20 and Rabbit, which have survived after the final phase of the eSTREAM project. We also present the implementation results of hardware-oriented stream ciphers and AES-CFB fur reference. According to our experiment, the encryption speeds of these software-based stream ciphers are in the range of 31-406Kbps, thus most of these ciphers are fairly acceptable fur sensor nodes. In particular, the survivors, SOSEMANUK, Salsa20 and Rabbit, show the throughputs of 406Kbps, 176Kbps and 121Kbps using 70KB, 14KB and 22KB of ROM and 2811B, 799B and 755B of RAM, respectively. From the viewpoint of encryption speed, the performances of these ciphers are much better than that of the software-based AES, which shows the speed of 106Kbps.