• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1262-1270
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• 2017

Among various decoding algorithms of low-density parity-check (LDPC) codes, the min-sum (MS) algorithm and its modified algorithms are widely adopted because of their computational simplicity compared to the sum-product (SP) algorithm with slight loss of decoding performance. In the MS algorithm, the magnitude of the output message from a check node (CN) processing unit is decided by either the smallest or the next smallest input message which are denoted as min1 and min2, respectively. It has been shown that multiplying a scaling factor to the output of CN message will improve the decoding performance. Further, Zhong et al. have shown that multiplying different scaling factors (called a 2-dimensional scaling) to min1 and min2 much increases the performance of the LDPC decoder. In this paper, the simplified 2-dimensional scaled (S2DS) MS algorithm is proposed. In the proposed algorithm, we figure out a pair of the most efficient scaling factors which multiplications can be replaced with combinations of addition and shift operations. Furthermore, one scaling operation is approximated by the difference between min1 and min2. The simulation results show that S2DS achieves the error correcting performance which is close to or outperforms the SP algorithm regardless of coding rates, and its computational complexity is the lowest comparing to modified versions of MS algorithms.

• Journal of Astronomy and Space Sciences
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• v.19 no.2
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• pp.123-132
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• 2002

The electron density and temperature in the topside ionosphere are observed by the ionosphere Measurement Sensor (IMS) onboard the KOMPSAT-1, which has the sun-synchronous orbit of the altitude of 685 km and the orbital inclination of $98^{\circ}$ with a descending node at 22:50LT. Observations have been analyzed to determine the seasonal variations of the electron density and temperature in the low-latitude region. Only the night-time (22:50LT) behavior on magnetically quiet days (Kp < 4) has been examined. Observations show a strong longitudinal and seasonal variation. Generally, in the dip equator the density increases and the temperature decreases. In equinox the latitudinal distributions of the electron density and temperature are quite symmetric about the dip equator. However, the local maximum of the density and the local minimum of the temperature shift toward the Northern hemisphere in summer solstice but the Southern hemisphere in winter solstice. Such variations are due to the influences of field-aligned plasma transport induced by F region neutral wind. Compared with the IRI95 model, the observed electron density and temperature show significant differences from those predicted by the IRI95 model.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.64-69
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• 2008

The objective of experiment was to investigate the effects of planting density on growth and yield of vegetable soybean, and to clarify the optimum planting density of vegetable soybean in the middle west region of Korea. The field experiment with 4 levels of planting density was carried out at Yesan area in $2005{\sim}2006$. The days from seeding to flowering and the days from seeding to harvesting and lodging were not significantly different among planting distance. The stem length was increased as planting distance was shortened but the number of node, branch, pod per branch, pod per individual, weight of stem and pod, one hundred pod weight and rate of 2+3 seed per pod were decreased as planting density was increased. The size of vegetable soybeans was not significantly different among planting distance, but the harvest index of vegetable soybean was decreased as planting distance was shortened. Yield of vegetable soybean was increased as planting distance was decreased. However, the approriate densities for stem and pod weight per a plant, number of pod per a branch and the vegetable soybean yield of 2+3 seed per pod were different from that density. The optimal planting distance of varieties was $60{\sim}25\;cm$ in Sunheukkong and Ilpumgeomjeongkong and was $60{\sim}35\;cm$ in Galmikong.

• Korean Journal of Medicinal Crop Science
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• v.2 no.1
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• pp.26-31
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• 1994

This experiment was conducted to study the effect of growth characteristics and yield by different planting density on Ligusticum chuanxiong Hort.Number of stem, leaf and branch on main stem were plant reduced by increasing the plant density. Stem height was showed the highest at $50{\times}15cm$ planting density, but diameter did not show significant difference at different planting density. Stem number in $m^2$ of field area showed negative correlation with leaf number and branch number on main stem. The height of first branched node became longer by increasing stem number, leaf number and branch number on stem in $m^2$ of field area. Rhizome yield showed negative correlation with stem number and leaf number per plant, but showed positive with stem number in $m^2$ of field area leaf number and branch number of main stem. Root and rhizome weight per plant decreased by increasing planting density, but root and rhizome yield in $m^2$ of field area were increased by high planting density.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.215-222
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• 1996

This study was conducted to compare the growth and yield, and to determine the optimum planting date and density in two improved black soybean varieties. The two varieties were planted by driller attached a tractor on May 21 and June 19, 1993, and treated five planting densities, respectively. Yield of Gumjeongkong 1 was similer for both planting dates, but that of Suwon 157 was remarkably reduced on June 19 planting compared to May 21. There was significant differences between planting dates in stem length, number of branches, seeds per plant, seed weight and yield. Planting density, also, significantly affected on stem length, number of branches and seeds per plant. Statistically significant interactions between planting date$\times$variety and planting date$\times$planting density were found at almost all characteristics, except between variety$\times$planting density. Optimum planting date and density of Gumjeongkong 1 for high yield were June 19 and 33, 000 plants per l0a, and those of Suwon 157 were May 21 and 22, 000 plants per l0a, respectively. The coefficient of variation at different planting densities was high at stem length, number of branches, seeds per plant and yield, but low at number of main stem node, seeds per pod and 100 seed weight.

• Korean Journal of Head & Neck Oncology
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• v.20 no.2
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• pp.135-142
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• 2004

Objectives: The purpose of this study was to evaluate for prognostic significance of VEGF expression and tumor angiogenesis in papillary carcinomas of the thyroid. Materials and Methods: The materials were 79 cases of papillary thyroid carcinomas, and age, sex, tumor size, multiplicity of tumor, capsular invasion, lymph node metastasis, recurrence, TNM stage, DeGroot stage and AMES scale were evaluated. An immunohistochemical stains for CD 34 to estimate microvessel density (MVD), and VEGF were done. MVD was defined as an average count of vessels per ${\times}400$ power field in the most vascularized area. VEGF expression was interpreted as 1+ and 2+ according to staining intensity and percentages of positive cells. Results: Mean score of MVD was $39.7{\pm}16.9.$ MVD were significantly higher in cases with capsular invasion (p=0.0001), lymph node metastasis (p=0.0001), TNM stage III (p=0.0022), DeGroot stage III (p=0.0163) and high risk group by AMES scale (p=0.0001). VEGF 2+ expression rate was significantly increased in cases with capsular invasion and lymph node metastasis (p=0.0006, p=0.0013), and in cases with TNM stage III, DeGroot stage III and high risk group by AMES scale (p=0.0236, p=0.0003, p=0.0293). In VEGF 2 + expression group, MVD was significantly higher than in VEGF 1 + group (p=0.0008), and MVD showed positive relation to VEGF 2 + expression (r=0.4616). Conclusion: VEGF expression and high MVD were significantly correlated to capsular invasion, lymph node metastasis, TNM stage III, DeGroot stage III and high risk group by AMES scale. The expression of VEGF and high MVD could be considered to be one of prognostic factor in papillary thyroid carcinomas.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.4
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• pp.59-70
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• 2003

Spatial data base system provides many query types and most of them are required frequent disk I/O and much CPU time. k-NN search is to find k-th closest object from the query point and up to now, several k-NN search methods have been proposed. Among these, MINMAX distance method has an aim not to access unnecessary node by adapting pruning technique. But this method accesses more disks than necessary while pruning unnecessary nodes. In this paper, we propose new k-NN search algorithm based on density of object. With this method, we predict the radius to be expected to contain k-NN objects using density of data set and search those objects within this radius and then adjust radius if failed. Experimental results show that this method outperforms the previous MINMAX distance method. This algorithm visit less disks than MINMAX method by the factor of maximum 22% and average 7%.

• The KIPS Transactions:PartC
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• v.17C no.3
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• pp.291-298
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• 2010

In wireless sensor networks, energy is the most important consideration because the lifetime of the sensor node is limited by battery. The clustering is the one of methods used to manage network energy consumption efficiently and LEACH(Low-Energy Adaptive Clustering Hierarchy) is one of the most famous clustering algorithms. LEACH utilizes randomized rotation of cluster-head to evenly distribute the energy load among the sensor nodes in the network. The random selection method of cluster-head does not guarantee the number of cluster-heads produced in each round to be equal to expected optimal value. And, the cluster head in a high-density cluster has an overload condition. In this paper, we proposed both a token based cluster-head selection algorithm for guarantee the number of cluster-heads and a cluster selection algorithm for uniform-density cluster. Through simulation, it is shown that the proposed algorithm improve the network lifetime about 9.3% better than LEACH.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.29-32
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• 2014

Background and Objective: Lung cancer is one of the malignant diseases which most seriously threat humansurvival and development. This study aimed to assess osteopontin (OPN) expression in non-small cell lung cancer (NSCLC) and any relationship with clinicopathological features. Methods: Immunohistochemistry was used to determine OPN expression and microvascular density (MVD) in 120 cases of NSCLC also undergoing clinical assessment. Results: Moderately positive expression of OPN was found in 34.6% (41/120) and strong expression in 47.5% (57/120) of the NSCLCs; OPN expression in carcinomas was higher than in pericarcinoma tissues (P<0.05). While no obvious association was observed with NSCLC patient age, gender, maximum diameter of the tumor and pathological type, OPN expression was more commonly detected in poorly differentiated carcinoma tissue and lymph node metastasis as well as at advanced clinical stage (P<0.05); OPN expression in cancer tissue was positively correlated with MVD (r = 0.839, P = 0.000). Conclusion: OPN plays an important role in promoting tumor angiogenesis and progress of NSCLCs and has the possibility to become the new target for therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4549-4552
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• 2013

The incidence of gastric cancer worldwide, and in particular in developing countries, has shown a marked increase. Poor prognosis of gastric cancer patients occurs due to the rapid metastasis of the disease via the lymphatic and blood vessels. The aim of this study was to investigate the expression and the clinical significance of D2-40 and CD34 in human gastric cancer. D2-40 and CD34 expression wasdetected in 1,072 cases of Chinese patients with gastric carcinoma using immunohistochemistry. The lymphatic vessel density (LVD) and microvessel density (MVD) were calculated and analyzed and the correlation with the clinicopathological factors and prognosis was determined. The LVD and MVD of the gastric cancer cases were significantly higher compared to those of normal tissues (P < 0.05). The expression of D2-40-LVD and CD34-MVD in the malignancies were positively related to the age, tumor size, invasion depth, lymphatic metastasis and pathological tumor-node-metastasis (pTNM) (P < 0.05); However, no statistically significant difference was identified between them with the patient gender (P > 0.05). Up-regulation of D2-40 and CD34 expression was significantly correlated with the poor survival rate in univariate and multivariate analyses. The LVD marked by D2-40 and the MVD marked by CD34 were positively correlated to the clinicopathological factors of the malignancies and may play important role in the development and progression of gastric cancer.