• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.345-359
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• 1989

This study was conducted to estimate genetic variation of Pinus densiflora in Kyungpook province which shows morphological variation between northern and southern types. Six isozymes sueh as IDH, ME, PGI, ADH, GOT and LAP was analyzed using megagametophyte tissue of seeds by electrophoresis and 16 populations of Pinus densiflora and 5 of Pinus thunbergii were tested. The results obtained were as follows ; 1. In P. densiflora, 13 Loci were found in 6 isozymes and 8 loci of them were polymorphic, having 24 alleles, while in Pinus thunbergii, there were 18 alleles detected from 6 loci among the same number of loci as in Pinus densiflora. 2. The genotypic frequency in Pinus densiflora vary slightly among populations for some isozymes, but most of them satisfied the law of Hardy-Weinherg equilibrium, while some populations such as Youngil for ADH and LAY, Youngyang for ADH and Bonghwa for LAY did not follow the law and showed high fixation index values and homozygosities higher than expected. 3. The variation among populations based on the genetic distance was small except populations of Youngju, Baegam, Gyungju and Sangju, however they could be clustered by three groups : northern Kyungpook group including Mt. Taebak, inland Kyungpook group represented by Sungju, Eusung and Kumleung population and coastal Kyungpook group represented by Baegam and Gyungju population. 4. No significant difference was found in 6 isozymes between northern and southern types of Pinus densiflora which was morphologically different. 5. The frequency of heterozygous loci per tree was higher in Pinus densiflora especially for ME-A and A DH-B, while that of homozygous loci was higher in Pinus thunbergii except for ADH-B, LAY-B and PGI-B locus.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.429-437
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• 2019

This study was conducted to examine the effect of humidification and shading during cutting propagation on growth and development of strawberry (Fragaria x ananassa Duch.) 'Maehyang' plants at a propagation stage. The runner cuttings were stuck on Nov. 23, 2017 in propagation benches set in a Venlo-type glasshouse. Four shading treatments, no shading (control, C), 55% shading with white lawn (W55), 55% black shading net (B55), or 100% black plastic film (B100) with either an intermittent fog system (H) or without fog system. The shading and fog systems were removed 2 weeks after sticking of strawberry cuttings. A nutrient solution for strawberry, which was developed by Yamazaki, was supplied once a day with electrical conductivity (EC) $1.6dS{\cdot}m^{-1}$ and pH 5.8. Growth parameters such as plant height, longest root, crown diameter, leaf chlorophyll, leaf area and fresh and dry weight were measured at 7 days and 26 days after sticking. There was no significant difference in growth of above-aerial part of strawberry. The overall growth of the strawberry roots was better grew by providing fog than that not provide fog. The root fresh weight and root dry weight after 26 days after sticking of strawberry cutting was the best in the treatment that provided fog system without shading (CH). The longest root after 26 days after sticking of strawberry cutting was the best in the treatments that provided fog system with either 55% white lawn (W55H) and 55% black shading net (B55H). These results suggest that morphogenesis of these plants were affected by humidification and shading types. In a broader perspective, these results can be used to optimize studies of other crops grown from cuttings.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.669-676
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• 2017

To understand the relationship between environmental factors and phytoplankton community structures and why early outbreaks of Cochlodinium polykrikoides occur in the inner bay of Korea, short-term investigations were conducted at 17 stations in the eastern part of the South Sea of Korea, with sessions every two weeks from July 7 to August 24, 2016. The water temperature increased from $22.3^{\circ}C$ in the first survey to $28.4^{\circ}C$ in the fourth survey, which was a rise of about $6.01^{\circ}C$. Salinity was relatively high at Stns. 8 13 in the inner bay. In the first survey, rainfall of about 150 mm was observed, so nutrients were supplied at a high level and a high concentrate of Chl. a was observed. Cryptophyta (Crpytomonas spp.) represented 58.3 % of the community, followed by Bacillariophyta at 33.8 %. In particular, at Stn. 5, Dinophyta Prorocentrum spp. accounted for a very high percentage, 32.2 %. In the second survey, low phytoplankton populations were observed, and Bacillariophyta (Chaetoceros spp.) accounted for 61.0 %. At Stn. 4, Skeletonema spp. showed high populations but did not appear at other stations even at a low density. In the third and fourth surveys, phytoplankton populations were very low. Bacillariophyta represented 78.0 % in the third study and 73.3 % in the fourth. Interestingly, although the appearance of C. polykrikoides was investigated at the beginning of the red tide in the coastal area, they were not observed inshore, implying that the likelihood of inflow by the germination of resting cysts was low for the inner bay during this study period. In addition, environmental characteristics such as salinity and nutrient presence were significantly different between sampling stations due to the existence of a semi-closed bay in the southern sea, resulting in dominant phytoplankton species and community composition differing in these short-term investigations.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.789-792
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• 2010

Major impacts of climate change expert that soil erosion rate may increase during the $21^{st}$ century. This study was conducted to assess the potential impacts of climate change on soil erosion by water in Korea. The soil loss was estimated for regions with the potential risk of soil erosion on a national scale. For computation, Universal Soil Loss Equation (USLE) with rainfall and runoff erosivity factors (R), cover management factors (C), support practice factors (P) and revised USLE with soil erodibility factors (K) and topographic factors (LS) were used. RUSLE, the revised version of USLE, was modified for Korean conditions and re-evaluate to estimate the national-scale of soil loss based on the digital soil maps for Korea. The change of precipitation for 2010 to 2090s were predicted under A1B scenarios made by National Institute of Meteorological Research in Korea. Future soil loss was predicted based on a change of R factor. As results, the predicted precipitations were increased by 6.7% for 2010 to 2030s, 9.5% for 2040 to 2060s and 190% for 2070 to 2090s, respectively. The total soil loss from uplands in 2005 was estimated approximately $28{\times}10^6$ ton. Total soil losses were estimated as $31{\times}10^6$ ton in 2010 to 2030s, $31{\times}10^6$ ton in 2040 to 2060s and $33{\times}10^6$ ton in 2070 to 2090s, respectively. As precipitation increased by 17% in the end of $21^{st}$ century, the total soil loss was increased by 12.9%. Overall, these results emphasize the significance of precipitation. However, it should be noted that when precipitation becomes insignificant, the results may turn out to be complex due to the large interaction among plant biomass, runoff and erosion. This may cause increase or decrease the overall erosion.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.1
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• pp.83-93
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• 2016

Objectives : The Center for Epidemiologic Studies Depression scale-Revised is a recently revised scale which has been reported as a valid tool for the assessment of depressive symptoms. It encompasses cardinal symptoms of depression described in the Diagnostic and Statistical Manual of Mental disorders, fourth edition. In this study, we assessed the reliability, validity and psychometric properties of the Korean version of the CESD-R(K-CESD-R). Methods : Forty-eight patients diagnosed as major depressive disorder, dysthymia, depressive disorder NOS according to the DSM-IV criteria using Mini International Neuropsychiatric Interview and 48 healthy controls were enrolled in this study. They were assessed with K-CESD-R, K-MADRS, PHQ-9, KQIDS-SR, STAI to check cross-validation. Statistical analyses were performed using calculation of Cronbach's alpha, Pearson correlation coefficient, Principal Component Analysis, ROC curve and optimal cut-off value. Results : The Cronbach's alpha of K-CESD-R was 0.98. The total score of K-CESD-R revealed significantly high correlations with those of K-MADRS, PHQ-9, KQIDS-SR(r=0.910, 0.966 and 0.920, p<0.001, respectively). Factor analysis showed two factors account for 76.29% of total variance. We suggested the optimal cut-off value of K-CESD-R as 13 according to analysis of the ROC curve which value sensitivity and specificity both equally. Conclusions : These Results showed that the K-CESD-R could be a reliable and valid scale to assess depressive symptoms. The K-CESD-R is expected as a useful and effective tool for screening and measuring depressive symptoms not only in outpatient clinic but also epidemiologic studies.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.1
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• pp.28-42
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• 2016

Objectives : The author tried to find out reasons why and how hysteria(and conversion disorder) patient numbers, which were so prevalent even a few decades ago, have decreased and the phenotype of symptoms have changed. Methods : The number of visiting patients diagnosed with conversion disorder and their phenotype of symptoms were investigated through chart reviews in a psychiatric department of a University hospital for the last 12 years. Additionally, the characteristics of conversion disorder patients visiting the emergency room for last 2 years were also reviewed. Those results were compared with previous research results even if it seemed to be an indirect comparisons. The research relied on Briquet P. and Charcot JM's established factors of the vicissitudes of hysteria(and conversion disorder) which has been the framework for more than one hundred and fifty years since hysteria has been investigated. Results : The author found decreased numbers and changes of the phenotype of the hysteria patients(and conversion disorder) over the last several decades. The decreased numbers and changes of the symptoms of those seemed to be partly due to several issues. These issues include the development of the diagnostic techniques to identify organic causes of hysteria, repeated changes to the symptom descriptions and diagnostic classification, changes of the brain nervous functions in response to negative emotions, and the influence of human evolution. Conclusions : The author proposed that the evolutionary brain discord reaction theory explains the causes of disappearance of and changes to symptoms of hysteria(conversion disorder). Most patients with hysteria(conversion disorder) have been diagnosed in the neurological department. For providing more appropriate treatment and minimizing physical disabilities to those patients, psychiatrists should have a major role in cooperating not only with primary care physicians but with neurologists. The term 'hysteria' which had been used long ago should be revived and used as a term to describe diseases such as somatic symptom disorder, functional neurological symptoms, somatization, and somatoform disorders, all of which represent almost the same vague concept as hysteria.

• 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.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.112-131
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• 2011

This article reports the results of scientific analysis using SEM-EDX, XRD, TG/DTA, performed on 5 green glaze samples of the brick and roofing tile excavated from the Sacheonwang temple site in Gyeongju in order to verify the chemical compositions and melting temperature. The glaze samples on 2 clay statues have similar chemical composition (PbO 74~81%, $SiO_2$ 14~18%) and melting temperature range ($970{\sim}1070^{\circ}C$), whereas the 2 tiles of goblin's face and 1 rhomb brick have different characteristics. Sample SC 003 (made of PbO 63~67%, $SiO_2$ 25~28%), one of the tiles of goblin's face, shows low melting temperature range (below $970^{\circ}C$), and sample SC 004 (composed of PbO 64~70%, $SiO_2$ 19~25% and melting point $970{\sim}1070^{\circ}C$), the other tile of goblin's face, shows different chemical characteristics compared with 2 clay statues. The green glaze on rhomb brick shows different composition compared with all the others from Sacheonwang temple site in that it does not show any impurity elements other than the main components (PbO 87~88%, $SiO_2$ 12~13%) with very low melting temperature range ($750{\sim}770^{\circ}C$). Surprizingly, the chemical and optical characteristics of this green-glaze on rhomb brick are very similar to that on the bricks from Yeongmyo temple site, Gyeongju. The above results indicate that raw material and manufacturing method are not same for 5 green-glaze samples from Sacheonwang temple site and therefore suggests that further study on the provenance of raw material such as lead isotope analysis is necessary. Our work will provide basic data for future reproduction study of green glazed brick of Sacheonwang temple site, Gyeongju and will also serve as a reference data for the study of raw material and manufacturing method of green glaze from other sites of cultural assets.

• Korean Journal of Heritage: History & Science
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• v.44 no.1
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• pp.182-195
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• 2011

Old big tree transcends the simple meaning of trees as they are the natural monuments that embody the people's history and culture of this land. The Cultural Heritage Administration of Korea (CHA) defines and protects old big tree based not only on the size of the tree but also on its definitive cultural and natural factors such as value, implications, and originality. This research aims to identify and analyze the habitation and measurements, the soil conditions, as well as the protective facilities of 14 old big tree spread throughout the Gangwondo. The research examined the soundness of the arboreal form, the degree of damage on the bark, as well as the quantity of leafs levels to evaluate the overall condition of growth and development. Then, the tree height, the eastwest and south-north width of the crown, the sternum circumference, and the root circumference were recorded to identify the measurements of the selected old big tree. Also, the research analyzed 9 elements such as soil texture, pH levels, and organic contents in order to determine the scientific characteristics of soil upon which the trees draw nutrition. Finally, the research evaluated supporting pillars, lightning rods, iron pulling-facilities, as well as notice boards to study the protective facilities of old big tree. The research procedures revealed that 78.57% of the old big tree identified as natural monuments in the Gangwondo have average to above average habitation conditions. Also, the average tree height reaches 18.80m above ground while the average root circumference measures 7.34m. Moreover, the results of the scientific analyses conducted on the soil elements determined that most chemical values were within the defined levels, with the exception of phosphoric acid levels falling within the hyper-nutritious range. Finally, although most of the protective facilities did support the habitation of the Old big tree, there were some supporting pillars and iron pulling-facilities that actually damaged the trees. This research means to provide foundational reference data for the analysis of the habitation and management conditions of natural monument old big tree within the Gangwondo. A follow-up topic led by the results of this research is the identification and analysis of correlating environmental elements that affect the habitation of the old big tree.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.40-49
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• 2019

Coarse woody debris (CWD), which is a component of the forest ecosystem, plays a major role in forest energy flow and nutrient cycling. In particular, CWD isolates carbon for a long time and is important in terms of slowing the rate of carbon released from the forest to the atmosphere. Therefore, this study measured the physiochemical characteristics and respiration rate ($R_{CWD}$) of CWD for Larix kaempferi and Pinus rigida in temperate forests in central Korea. In summer 2018, CWD samples from decay class (DC) I to IV were collected in the 14 forest stands. $R_{CWD}$ and physiochemical characteristics were measured using a closed chamber with a portable carbon dioxide sensor in the laboratory. In both species, as CWD decomposition progressed, the density ($D_{CWD}$) of the CWD decreased while the water content ($WC_{CWD}$) increased. Furthermore, the carbon concentrations did not significantly differ by DC, whereas the nitrogen concentration significantly increased and the C/N ratio decreased. The respiration rate of L. kaempferi CWD increased significantly up to DC IV, but for P. rigida it increased to DC II and then unchanged for DC II-IV. Accordingly, except for carbon concentration, all the measured characteristics showed a significant correlation with $R_{CWD}$. Multiple linear regression showed that $WC_{CWD}$ was the most influential factor on $R_{CWD}$. $WC_{CWD}$ affects $R_{CWD}$ by increasing microbial activity and is closely related to complex environmental factors such as temperature and light conditions. Therefore, it is necessary to study their correlation and estimate the time-series pattern of CWD moisture.