• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.477-484
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• 1999

This study was conducted to investigate the effect of forest road on the suspended sediment yield into a stream in the small forest watershed. The samples of suspended sediment yield were collected at surveying points A and B in mountains watersheds unaffected by forest road, and at surveying point C affected by forest road. When hourly change of suspended sediment concentration was investigated, it showed the highest increase along the forest road, and the peak of suspended sediment concentration due to the watershed characteristics of each surveying point occurred before or at the same time with, the peak of discharge. This may be due to the time lag in which stagnated unstable suspended sediment moved strongly upon rainfall. Although suspended sediment load varied depending upon rainfall factors and surveying period, suspended sediment load per unit watershed flowed out 4.1 times more at the point C than at the point A and B. The suspended sediment load on 18~19 September, 1998, strongly affected by rainfall factors, was 4.179g/sec/㏊ at the point C, and 0.343g/sec/㏊ and 0.147g/sec/㏊ at the point A and B, respectively. This load was 12 times higher at the point C than at the point A and 28 times higher than at the point B.

• KSBB Journal
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• v.21 no.4
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• pp.292-297
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• 2006

One of the steps in angiogenesis is the degradation of the underlying basement membrane via proteases. Endothelial cells release proteinases to degrade the extracellular matrix for their sprouting in vivo. In this study, we examined the effect of water extracts of Phellinus linteusis(Phellinus extracts) and combination of Phellinus extracts and fibroblast growth factor(FGF-2) on cultured porcine pulmonary artery endothelial cells(PPAECs). Phellinus extracts induced sprouting of PPAECs, which was inhibited by MMPs and plasmin inhibitors, and induced the secretion of matrix metalloproteinase-3(MMP-3) and plasmin. At high concentration of Phellinus extracts($200{\sim}400{\mu}g/mL$), the active MMP-2 secretion was induced. It is therefore, suggested that Phellinus extracts induces the sprouting of cultured endothelial cells by means of increased active MMP-2 and plasmin secretion. Also, combination with Phellinus extracts and FGF-2 produced an enhanced effect on sprouting and secretion of active MMP-2, and MMP-3 and plasmin from PPAECs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5737-5744
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• 2013

This study was performed to identify the association between the menarche experience and mental health in middle school girls aged 14. The subjects were selected using data from the 8th Korean Youth Risk Behavior Web-based Survey (KYRBWS-V), which included 5,991 girls in 1st grade of middle school. Data were analyzed using the PASW 18.0 program for frequency analysis, t-test, chi square and logistic regression analysis. As to results, we found 4,473 girls who had experienced menarche (mean age, 12.8 0.9 years) and 1,518 girls hadn't experienced menarche. In the logistic regression analysis between the menarche experience and mental health behaviors, the odds ratio (OR) [95% confidence interval (CI)] for perceived stress (OR=1.39, 1.20-1.62, p<0.001), perceived depression (OR=1.25, 1.10-1.42, p<0.05), suicide thinking (6OR=1.60, 1.38-1.87, <0.001), suicide planning (OR=1.66, 1.33-2.81, p<0.001) and suicide trial (OR=1.42, 1.09-1.86, p<0.05) were higher in the menarche experience group than in the menarche non-experience group. Our results indicate, a viable association between the menarche experience and mental health in the 1st grade of middle school girls, and suggests that the menarche experience is an important factor influencing adolescent girls' mental health.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.1
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• pp.9-13
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• 2002

It is well known that the maximum amplitude of accommodation decreases with increasing age.(Presbyopia). With single vision lenses presbyopia can be corrected only for one viewing distance. With progressive power lenses presbyopia can be corrected for all viewing distances. But there are some other changes in the visual system with age which can not be corrected by spectacle lenses. Pupillary diameter decreases and the light transmission of the ocular media decreases. Therefore old people need more light, they need better illumination. Cone density in the retina decreases, this is only one example for changes in the sensory system. These changes in the visual system cause changes in visual functions. At the age of 80 visual acuity has decreased to half. Contrast sensitivity for gratings decreases mainly for high spatial frequencies very important is the increase of stray light in the ocular media and therefore the increase of glare. Veiling luminance increases by a multiple of approximately 4, Dark adaptation gets slower and light sensitivity is approximately 2 log units (factor 100) less when the eye is completely dark adapted. Also colour vision gets worse, especially at low luminances. Elderly people have problems with visual tasks which require divided attention between foveal and peripheral vision. An example is the measurement of the useful field of view. This useful field of view be expanded (improved) by visual training.

• Environmental and Resource Economics Review
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• v.23 no.1
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• pp.1-19
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• 2014

Weather seems to influence industries in a variety of ways. On a day-to-day basis, it is the most volatile external factor influencing consumer and market behavior. And, because weather is constantly changing, industries must deal with a continuously shifting array of opportunities and risks. This study aims to examine how climate and weather changes and information, as external environmental factors, have affected the Korean industries, particularly marine shipping and logistics. To find out the economic value of marine weather information, we use measurable results of VVOS(Vessel and Voyage Optimization Services) in the ocean shipping, which the marine weather software tool can save fuel costs up to 4%. When the fuel saving is same as VVOS's performance, the saving of Korean flag ship is estimated about 62 billion won and the saving of total flag ship is estimated about 519 billion won. However, coastal shipping companies have been struggling with the heavy weather factors, such as wave height, wave period and wind. Major findings are that wind and wave height have a significant negative effect on cargo transport, while wave period has a significant positive effect on cargo transport. And to conclude, when we use efficiently the marine weather information, we can increase cargo transport and save fuel costs etc.

• Journal of Distribution Science
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• v.14 no.6
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• pp.107-118
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• 2016

Purpose - Over 90% of Domestic logistics industry is small enterprise and they are experiencing growth stagnation due to price-based competition structure rather than constructing logistics service of high added value. In order to get over this situation and pursue the development of logistics industry, strengthening its competitiveness, through inter-enterprise cooperative network build-up, would be a key alternative. Therefore, in this study, an index for measuring inter-enterprise cooperation level of Joint logistics business will be developed as a typical collaborative business model in logistics industry. Moreover, a strengthening competitiveness method suggests a developmental step and a key management index to mature in logistics industry. Research Design, Data, Methodology - This study is an index development research for measuring inter-enterprise cooperation level of logistics industry. Such a level was measured by performing a survey by targeting enterprises that participated in Joint logistics business. The targeting enterprises are typical cooperative models in logistics industry. Measurement items were developed which were based on the presented items in existing research. Question items were composed of selection type questions as answering Yes/No. They measures implementation status of corporate activity and detailed activity items measuring qualitative level. Total samples were based on 116 enterprise samples including 90 logistics enterprises and 26 shippers. In addition, by evaluating the importance for Joint logistics business recognition with personnel working level, the weight of measuring variable was extracted. This study has built an assessment tools (LPCI) on Joint logistics business cooperation level in a situation where there are no previous studies on joint logistics business, this study is meaningful for other studies. Results - As a result of analyzing LPCI presented in this study, the score of logistics enterprise was represented as 59.9 points based on full score of 100 points and that of shippers as 47.2 points and cooperation level among enterprises participated in Joint logistics business was revealed to be very low. In particular, as a result of measuring the importance between logistics enterprise and shippers, the difference by each measurement standard was represented among those enterprises. This difference is considered to be a key factor that cooperative operational conformity between logistics enterprises and shippers is represented to be low. Conclusions - As most joint logistics business, being promoted at present, is sharing facility and information with joint logistics business, it is hard to find such a joint logistics business in reality based on cooperative business model in main cooperation agents. Therefore, competitiveness of logistics industry could be strengthened by promoting joint logistics business based on their mutual cooperation among enterprises. In other words, it is to secure sustainable competitiveness of joint logistics business together with creation of new market by inter-enterprise cooperation based on integration of basic logistics business.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.809-815
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• 1997

A series of experiments were conducted to study effects of osmolality and $Ca^{2+}$ on sperm motility in marbled sole, Limanda yokohamae. Spermatozoa were immotile when the milt was mixed with solutions (electrolyte or non-electrolyte) of lower osmolality than the average seminal plasma osmolality (351 mOsm/kg), but became motile after mixing milt with an hyperosmotic solution. However, with the osmolality above 1,639 mOsm/kg spermatozoa ceased their movement. When the milt was suspended in the $Ca^{2+}$ free artificial seawater (ASW) containing ethylenglycoltriamine (EGTA), the percentage of motile spermatozoa decreased in proportion to the increase of EGTA. Most spermatozoa were quiescent in a medium containing 3 mM EGTA. The motility of spermatozoa prevented by 3 mM EGTA was recovered by the subsequent addition of $Ca^{2+}$ over the concentration of 0.25 mM. Effects of calmodulin antagonist, trifluoperazin (TFP) on spermatozoa were examined to elucidate the possible functions of calmodulin in sperm motility. TFP immobilized spermatozoa 5n ASW at the concentration of 0.5 M. These findings suggest that calcium is an effective external factor in the initiation process of sperm motility.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.823-833
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• 1997

To clarify the annual reproductive cycle of the banded catfish, Pseudobagrus fulvidraco (Richardson), the seasonal changes in histological aspect of gonad and liver were examined. The adult fish was raptured from the upper stream of Young-San river, Chunnam in each month from May 1992 to June 1993. Based on the annual changes in GSI (gonadosomatic index), HSI (hepatosomatic index), CF (condition factor) and histological aspects of the gonads, the annual reproductive cycle were classified into 5 periods as follows: 1) Growing phase (from April to early May): The value of GSI increased and the size of oocytes in perinucleolus stage in oocytes increased gradually. Spermatogonia were developed actively from the epithelial tissues of seminiferous tubules. 2) Maturing phase (from Hay to early June): GSI levels increased rapidly in both sex. Oocytes at various developmental stages were observed. Appearance of active spermatogenesis were observed. 3) Mature and spawning phase (from June to August): High values of GSI remained static and oocytes accumulated significant quantitis of yolk globules. 4) Degenerating phase (from September to November): GSI levels decreased and ovaries were filled mostly with oocytes at the perinucleolus stage. Hepatic cells accumulated significant amounts of lipid droplets. 5) Resting period (from December to March) : Low values of GSI were kept and the size of oocytes at the perinucleolus stage did not increase. Spermatogenesis was not observed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.2
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• pp.106-117
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• 2006

We measured the concentrations of organic matter and metallic elements (Al, Fe, Cr, Mn, Ni, Cu, Zn, As, Cd, Pb and Hg) in the surface sediments of Masan Harbor (in the southern sea, Korea) to evaluate the geochemical characters of sediment and the pollutions by organic matter and metallic elements. The mean grain size of the surface sediments in the study area ranged from $5.6{\phi}$ to $7.8{\phi}$, indicating silt sediment. The water content of the surface sediments exceeded 60% except at some stations. The contents of ignition loss (IL), total organic carbon (TOC) and total nitrogen (TN) ranged from 7.2-14.3%, 1.2-3.2%, and 0.10-0.28%, respectively. Based on the C/N ratios, the organic matter in the surface sediments of Masan Harbor may originate from terrigenous sources including fluvial inputs (mainly sewage in urban areas). The chemical oxygen demand (COD) and acid volatile sulfide (AVS) ranged from $11.3-29.9\;mgO_2/g\;dry$ and 0.20-4.47 mgS/g dry, respectively, and low concentrations were observed near a shipping route. In addition, the concentrations of metallic elements showed large spatial variations in Masan Harbor and the distributions of metallic elements were also comparable to those of organic matter. This implies that the distributions of organic matter and metallic elements in the surface sediments of Masan Harbor are mainly controlled by biogenic matter and artificial action (mainly dredging). In addition, we calculated the enrichment facto. (EF) and geoaccumulation index (Igeo) in order to evaluate pollution by metallic elements. The enrichment of metallic elements relative to Al was three to eighteen times higher at the study sites, compared to levels in the Earth's crust except for Fe, Ni and Mn. In addition, the Igeo class indicated that the surface sediments in the study area were moderately to strongly polluted in terms of metallic elements.

• The Korean Journal of Rehabilitation Nursing
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• v.1 no.1
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• pp.51-60
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• 1998

The result of studying papers about management of lower back pain published in domestic and foreign nursing and medical magazines in these 10 years is as follows ; 1. General characteristic of lower back pain ; 1) In sex distribution, there were more men than women in 5 papers and more women than men in 4 papers among 9 papers surveryed. 2) In age distribution, thirties to forties of patients had more lower back pain as surveyed by general hospitals and fifties to sixties of patients had more lower back pain as surveyed by oriental medical hospitals. 3) In cause factor, there were 50 to 65% of sprain, 32 to 44% of herniated intervertebral disc and 13 to 29% of degenerative changes. 4) In symtom distribution, there were 26 to 57% of lower back pain, 42 to 65% of lower back pain with radiating pain and 34 to 99% of paravertevral muscle spasm. 5) In period of pain management distribution, 18 to 40% of patients experienced pain for less than 6 months and 59 to 82% of them experienced pain for more than 6 months in 3 papers among 4 papers. 6) In surveying the treatment, 66 to 88% of patients had conservative treatment and there were treatments of general hospital, oriental medicine, self remedy and traditional practice in conservative treatment. 7) In job distribution, 12 to 50% of them were housekeepers, 23 to 31% office workers, 4.6 to 36% blue color workers and 11 to 15% students. 2. As psychological character lower back pain paients had anxiety, depression, anger-hostility, phobic anxiety, neurasthenia, hypochondriasis, and interpersonal sensitivity. 3. To distinguish the cause of lower back pain, plain lumbar roentgenogram, straight leg rasing test, eletromyelogic findings, somatosensory evoked potentials CT and MRI were performed. 4. To relieve lower back pain. epidural adhesiolysis, epidulal injection of local anesthetic in mixture with steroid, lumbar spinal root block, low level laser therapy, acupuncture like transcutaneous nerve stimulation(AL TENS), topical capsaicin and lumbar orthotics were used in medical field, and relaxation technique was used in nursing field. 5. Mckenzie's extension exercise and William's flexsion exercise for lower back pain were used in medical field and Yoga exercise was applied in nursing field. 6. The more school education and self efficacy were high, the better they had active coping lower back pain positively and the less self efficacy was the more they had serious pain. As a result of studying the paper there have been very little research for lower back pain in nursing fields of Korea and foreign countries. Because 60 to 80% of population expeience lower back pain at least more than once, it is necessary to develop the study and clinical practice for management of lower back pain.