• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1166-1172
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• 2018

Purpose: To investigate the efficacy, and identify predictors of success of selective laser trabeculoplasty (SLT) in open-angle glaucoma (OAG) patients after adjusting for intraocular pressure (IOP) changes in the untreated fellow eye. Methods: This retrospective chart review included 52 eyes of 52 OAG patients who underwent SLT in one eye and were followed-up for at least 1 year after the procedure. The IOP was measured before the treatment, at 1, 2, and 3 months posttreatment, and every 3 months thereafter. To account for the possible influence of IOP fluctuations on laser outcomes, post-laser IOP values of the treated eye of each patient were also analyzed, after adjusting for IOP changes in the untreated fellow eye. Success was defined as an IOP decrease ${\geq}20%$ of the pretreatment IOP. The success rate was determined based on Kaplan-Meier survival analysis and factors predictive of success were analyzed using the Cox proportional hazard model. Results: The mean pretreatment IOP was $23.17{\pm}6.96mmHg$. The mean IOP reduction was $5.59{\pm}4.78mmHg$ (29.7%) and the success rate was 65.4% at 1 year. The adjusted mean IOP reduction was $4.70{\pm}4.67mmHg$ (23.9%) and the adjusted success rate was 53.9%. Pretreatment IOP was associated with SLT success; the higher the pretreatment IOP, the greater the post-laser IOP reduction (p = 0.025). Age and mean deviation index did not show a significant association with SLT success (p = 0.066 and p = 0.464, respectively). Conclusions: SLT is a safe and effective alternative method of IOP reduction in OAG patients. Herein, pretreatment IOP was the only factor significantly associated with SLT success. IOP fluctuations of the untreated eye should be considered for a better understanding of the impact of treatment.

• Korean Journal of Remote Sensing
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• v.26 no.2
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• pp.251-262
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• 2010

In order to provide quantitative control of the standard products of Geostationary Ocean Color Imager (GOCI), on-board radiometric correction, atmospheric correction, and bio-optical algorithm are obtained continuously by comprehensive and consistent calibration and validation procedures. The calibration/validation for radiometric, atmospheric, and bio-optical data of GOCI uses temperature, salinity, ocean optics, fluorescence, and turbidity data sets from buoy and platform systems, and periodic oceanic environmental data. For calibration and validation of GOCI, we compared radiometric data between in-situ measurement and HyperSAS data installed in the Ieodo ocean research station, and between HyperSAS and SeaWiFS radiance. HyperSAS data were slightly different in in-situ radiance and irradiance, but they did not have spectral shift in absorption bands. Although all radiance bands measured between HyperSAS and SeaWiFS had an average 25% error, the 11% absolute error was relatively lower when atmospheric correction bands were omitted. This error is related to the SeaWiFS standard atmospheric correction process. We have to consider and improve this error rate for calibration and validation of GOCI. A reference target site around Dokdo Island was used for studying calibration and validation of GOCI. In-situ ocean- and bio-optical data were collected during August and October, 2009. Reflectance spectra around Dokdo Island showed optical characteristic of Case-1 Water. Absorption spectra of chlorophyll, suspended matter, and dissolved organic matter also showed their spectral characteristics. MODIS Aqua-derived chlorophyll-a concentration was well correlated with in-situ fluorometer value, which installed in Dokdo buoy. As we strive to solv the problems of radiometric, atmospheric, and bio-optical correction, it is important to be able to progress and improve the future quality of calibration and validation of GOCI.

• Journal of Korea Port Economic Association
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• v.34 no.3
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• pp.17-52
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• 2018

The purpose of this paper is to measure the clustering change and analyze empirical results. Additionally, by using k-means, hierarchical, and mixed models on Asian container ports over the period 2006-2015, the study aims to form a cluster comprising Busan, Incheon, and Gwangyang ports. The models consider the number of cranes, depth, birth length, and total area as inputs and container twenty-foot equivalent units(TEU) as output. Following are the main empirical results. First, ranking order according to the increasing ratio during the 10 years analysis shows that the value for average linkage(AL), mixed ward, rule of thumb(RT)& elbow, ward, and mixed AL are 42.04% up, 35.01% up, 30.47%up, and 23.65% up, respectively. Second, according to the RT and elbow models, the three Korean ports can be clustered with Asian ports in the following manner: Busan Port(Hong Kong, Guangzhou, Qingdao, and Singapore), Incheon Port(Tokyo, Nagoya, Osaka, Manila, and Bangkok), and Gwangyang Port(Gungzhou, Ningbo, Qingdao, and Kasiung). Third, optimal clustering numbers are as follows: AL(6), Mixed Ward(5), RT&elbow(4), Ward(5), and Mixed AL(6). Fourth, empirical clustering results match with those of questionnaire-Busan Port(80%), Incheon Port(17%), and Gwangyang Port(50%). The policy implication is that related parties of Korean seaports should introduce port improvement plans like the benchmarking of clustered seaports.

• Journal of Korea Port Economic Association
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• v.32 no.1
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• pp.29-58
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• 2016

The purpose of this paper is to show the clustering trend and the comparison of empirical results and is to choose the clustering ports for 3 Korean ports(Busan, Incheon and Gwangyang Ports) by using the bootstrapped DEA(Data Envelopment Analysis) and game Cross-efficiency models for 38 Asian ports during the period 2003-2013 with 4 input variables(birth length, depth, total area, and number of cranes) and 1 output variable(container TEU). The main empirical results of this paper are as follows. First, bootstrapped DEA efficiency of SW and LT is 0.7660, 0.7341 respectively. Clustering results of the bootstrapped DEA analysis show that 3 Korean ports [ Busan (6.46%), Incheon (3.92%), and Gwangyang (2.78%)] can increase the efficiency in the SW model, but the LT model shows clustering values of -1.86%, -0.124%, and 2.11% for Busan, Gwangyang, and Incheon respectively. Second, the game cross-efficiency model suggests that Korean ports should be clustered with Hong Kong, Shanghi, Guangzhou, Ningbo, Port Klang, Singapore, Kaosiung, Keelong, and Bangkok ports. This clustering enhances the efficiency of Gwangyang by 0.131%, and decreases that of Busan by-1.08%, and that of Incheon by -0.009%. Third, the efficiency ranking comparison between the two models using the Wilcoxon Signed-rank Test was matched with the average level of SW (72.83 %) and LT (68.91%). The policy implication of this paper is that Korean port policy planners should introduce the bootstrapped DEA, and game cross-efficiency models when clustering is needed among Asian ports for enhancing the efficiency of inputs and outputs. Also, the results of SWOT(Strength, Weakness, Opportunity, and Threat) analysis among the clustering ports should be considered.

• The Korean Journal of Malacology
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• v.27 no.2
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• pp.131-141
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• 2011

Boring caracteristics, boring rate, and predation, rates on the valves of the seed and adult clams of Meretrix petechialis by Glossaulax didyma didyma in the shellfish aquafarm and the indoor rearing aquarium were investigated by various morphometric data. The investigations were carried out from June to September, 2007. The morphology of drilled holes on the valves of M. petechialis showed the crater type as seen in the spats of Ruditapes philippinarum and M. lusoria. The sizes of the outer diameters of holes were greater than the inner diameters of the holes on the valves of M. petechialis in the shellfish aquafarm and the indoor aquarium at the laboratory. On the whole, the sizes of the holes on the valves of the seeds of M. petechialis was smaller than those bored holes on the adult valves. The location of the bored holes on the valves of the seeds varied widely with the the sizes of the individuals of M. petichialis, while most of holes on the valves of adult clams were located near the umbo position of the valves of the clams in the shellfish aquafarm and the indoor aquarium at the laboratory. On the whole, the outer and inner diameters of the bored holes increased with increase of shell lengths of the clams in the shellfish aquafarm and the indoor rearing aquarium at the laboratory. The authors could confirm experimentally the boring snail, G. didyma didyma, drilled the seeds and adult clams of M. petechialis. In the experiments for 15 days (three times repeated) in the indoor rearing aquarium at the laboratory, the mortality of dead shells to total shells of M. petechialis by boring snail Glossaulax didyma didyma was totally average 41.5%, and percent of drilled shells to total dead shells of clams by the boring snail was average 47.1%. Of total shells, percent of drilled shells to total shells of clams by the boring snail was totally average 19.3%. Predation of G. didyma didyma were greater at night than the day time. Average 0.5 seed and adult individuals of M. petewchialis were consumed per G. didyma didyma, per day. Predation varied with shell lengths of M. petechialis and shell widths of G. didyma didyma.

• Food Science and Preservation
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• v.25 no.1
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• pp.44-51
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• 2018

The purpose of this study is to present the results as basic data for establishing proper storage conditions and distribution conditions of actual farms at point of increasing concern about hygiene and palatabiltiy of consumers to food. In this study, three farmhouses of dried persimmons prepared using different storage conditions were selected in Sangju (Korea). The dried persimmons were stored for 90 days. Changes in temperature and humidity were measured with a temperature and humidity recorder under each storage condition, and physicochemical analysis and sensory evaluation were performed. The average temperatures of farmhouse A, B and C were approximately $-22--23^{\circ}C$, $-19--18^{\circ}C$ and $-25^{\circ}C$ respectively. The humidities of A, B and C were 62-63%, 59-60%, and 66-67%, respectively, and the moisture contents of all farmhouses increased during the storage period, with farmhouse B showing the most rapid increase. Free sugars increased, except for those from farmhouse C. Persimmons from farmhouse B showed the greatest changes in chewiness and hardness. The values of $a^*$ and $b^*$ were significantly decreased in persimmons from farmhouse B, and the color difference value of farmhouse B was dramatically increased. Sensory evaluation showed that the color preference tended to decrease compared with the initial value. Only farmhouse B showed decreased overall acceptability. Moreover, farmhouse B had the highest storage temperature and lowest humidity. Therefore, our results showed that storage at a low temperature and high humidity was important for manufacturing high-quality dried persimmons.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.448-454
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• 2021

This study was conducted to the effect of low air temperature and light intensity conditions on yield and quality of tomato at the early stage of growth in Korea. Inplastic greenhouses, low temperature and low temperature with shade treatments were performed from 17 to 42 days after plant. Tomato growing degree days were decreased 5.5% due to cold treatment during the treatment period. Light intensity decreased 74.7% of growing degree days due to shade. After commencing treatments, the plant growth decreased by low temperature and low radiation except for height. Analysis of the yield showed that the first harvest date was the same, but the yield of the control was 3.3 times higher than low temperature with shade treatment. The cumulative yields at 87 days after transplanting were 1734, 1131, and 854 g per plant for control, low temperature, and low temperature with shade, respectively. The sugar and acidity of tomatoes did not differ between treatment and harvesting season. To investigate the photosynthetic characteristics according to the treatment, the carbon dioxide reaction curve was analyzed using the biochemical model of the photosynthetic rate. The results showed that the maximum photosynthetic rate, J (electric transportation rate), TPU (triose phosphate utilization), and R_d (dark respiration rate) did not show any difference with temperature, but were reduced by shading. Vcmax (maximum carboxylation rate) was decreased depending on the low temperature and the shade. Results indicated that low temperature and light intensity at the early growth stage can be inhibited the growth in the early stage but this phenomenon might be recovered afterward. The yield was reduced by low temperature and low intensity and there was no difference in quality.

• Journal of Korea Port Economic Association
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• v.37 no.1
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• pp.31-70
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• 2021

The purpose of this paper is to measure the clustering change and analyze empirical results, and choose the clustering ports for Busan, Incheon, and Gwangyang ports by using Hierarchical clustering(single, complete, average, and centroid), Silhouette, and 2SCE[the Second Stage(Type II) cross-efficiency] matrix clustering models on Asian container ports over the period 2009-2018. The models have chosen number of cranes, depth, birth length, and total area as inputs and container TEU as output. The main empirical results are as follows. First, ranking order according to the efficiency increasing ratio during the 10 years analysis shows Silhouette(0.4052 up), Hierarchical clustering(0.3097 up), and 2SCE(0.1057 up). Second, according to empirical verification of the Silhouette and 2SCE models, 3 Korean ports should be clustered with ports like Busan Port[ Dubai, Hong Kong, and Tanjung Priok], and Incheon Port and Gwangyang Port are required to cluster with most ports. Third, in terms of the ASEAN, it would be good to cluster like Busan (Singapore), Incheon Port (Tanjung Priok, Tanjung Perak, Manila, Tanjung Pelpas, Leam Chanbang, and Bangkok), and Gwangyang Port(Tanjung Priok, Tanjung Perak, Port Kang, Tanjung Pelpas, Leam Chanbang, and Bangkok). Third, Wilcoxon's signed-ranks test of models shows that all P values are significant at an average level of 0.852. It means that the average efficiency figures and ranking orders of the models are matched each other. The policy implication is that port policy makers and port operation managers should select benchmarking ports by introducing the models used in this study into the clustering of ports, compare and analyze the port development and operation plans of their ports, and introduce and implement the parts which required benchmarking quickly.

• Journal of Cadastre & Land InformatiX
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• v.48 no.2
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• pp.79-98
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• 2018

The purpose of this study is to suggest a model analysing spatio-temporal characteristics of the civil complaints for the officially assessed land price based on big data mining. Specifically, in this study, the underlying reasons for the civil complaints were found from the spatio-temporal perspectives, rather than the institutional factors, and a model was suggested monitoring a trend of the occurrence of such complaints. The official documents of 6,481 civil complaints for the officially assessed land price in the district of Jung-gu of Incheon Metropolitan City over the period from 2006 to 2015 along with their temporal and spatial poperties were collected and used for the analysis. Frequencies of major key words were examined by using a text mining method. Correlations among mafor key words were studied through the social network analysis. By calculating term frequency(TF) and term frequency-inverse document frequency(TF-IDF), which correspond to the weighted value of key words, I identified the major key words for the occurrence of the civil complaint for the officially assessed land price. Then the spatio-temporal characteristics of the civil complaints were examined by analysing hot spot based on the statistics of Getis-Ord $Gi^*$. It was found that the characteristic of civil complaints for the officially assessed land price were changing, forming a cluster that is linked spatio-temporally. Using text mining and social network analysis method, we could find out that the occurrence reason of civil complaints for the officially assessed land price could be identified quantitatively based on natural language. TF and TF-IDF, the weighted averages of key words, can be used as main explanatory variables to analyze spatio-temporal characteristics of civil complaints for the officially assessed land price since these statistics are different over time across different regions.

• Phonetics and Speech Sciences
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• v.11 no.3
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• pp.9-21
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• 2019

This study aimed to compare the prosodic characteristics of North Korean defectors and South Koreans in three types of sentences (declarative, interrogative, and negative) in two reading tasks (short and dialogue) through acoustic analysis and auditory-perceptual evaluation. In addition, this study examined the relationship between the auditory-perceptual evaluation scores and self-assessment questionnaires on intonation for North Korean defectors. The participants were 15 North Korean defectors and 15 Korean speakers with standard Seoul accents. For statistical analysis, three-way mixed ANOVA and multivariate analysis were performed within the three types of sentences in the reading tasks through acoustic analysis and the Mann-Whitney U Test for auditory-perceptual evaluation. Pearson's product-moment correlation coefficients were also used to identify the correlations between the results of the self-assessment questionnaire on intonation and the auditory-perceptual evaluation. The North Korean defectors were found to have a significantly lower pitch range and auditory-perceptual evaluation score than South Koreans in reading tasks. Moreover, there was a significant correlation between their auditory-perceptual evaluations and self-assessment questionnaires on intonation. The study findings suggest that North Korean defectors, who face many challenges with intonation, showed a tendency to think that their intonation differed from the standard Korean intonation and showed better auditory evaluation results for interrogative sentences.