• Journal of Environmental Impact Assessment
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• v.13 no.4
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• pp.197-211
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• 2004

Visibility impairment was known as an indicator of the increased air pollution. In many previous studies, it is known that both directly emitted fine particles mainly from vehicles and secondary aerosols from photochemical reactions could contribute to this visibility impairment in addition to the meteorological condition. Furthermore, the visibility showed different change patterns according to the geographical condition. In order to research into the influence of these factors on visibility, this study analyzed the visibility at 15:00, observed from 1990 to 2001 in Seoul, Ganghwa, Susan, Gwangju, Jeju. As a result, the visibility was increased in Seoul except the rainfall period, but in Susan, Gwangju, Jeju, it decreased with the relative humidity (RH). Especially, in Seoul, the number of low visibility days was larger than other sites and variations of the visibility were sensitive to the concentration of air pollutants, such as TSP, $NO_2$, $O_3$. The visibility impairment was mainly observed in meteorological condition of RH<50% and relatively stationary front. Therefore it is inferred that photochemical smog could lead to the low visibility in Seoul. On the other hands, in Ganghwa and Susan, when RH was 60~70%, the low visibility observed under the influence of the transports of air pollutants from nearby cities as well as humid air mass from coastal region. And in Jeju, sea fog and humid air mass caused the visibility impairment when the RH was larger than 80%. Finally, during the observational period, some cases of low visibility phenomena were simultaneously observed in the vast region including Seoul, Susan, Ganghwa. It not only includes the visibility aggravation by Asian Dust, but also could be caused by the movement and diffusion of flying dust or secondary aerosols. Moreover, the result shows that these phenomena could be mainly influenced by meteorological factors covering the wide regions.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.6
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• pp.57-68
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• 2021

The purpose of this study is to investigate the effect of location satisfaction of innovative start-ups, located in capital and non-capital areas, on the intention of relocation. The analysis was based on the data of a survey of 231 innovative start-ups that were founded less than 7 years ago. 10 factors related to the aspects of business management, network building, and business environment were considered as location satisfaction of start-ups. The dependent variable was whether innovative start-ups plan to relocate. First, it was confirmed that in the case of innovative start-ups in capital area, the intention to relocate was found to decrease when the location satisfactions related to the promptly provision of products and services to consumers and ease of supplying labor were increased. Second, in the case of innovative start-ups in non-capital area, it was found that the intention to relocate was found to decrease when the location satisfactions related to creating a network, convenient transportation and free and creative start-up environment were increased. In addition, it was found that the higher the sales of start-ups in non-capital area, the lower their intention to relocate while the higher firm age of start-ups in non-capital area, the higher their intention to relocate. This study has an academic contribution to examining the relationship between between the location satisfactions of start-ups and the intention to relocate, which has been rarely addressed in Korea, and to shedding light on the difference in capital and non-capital areas. Furthermore, this study has policy implications since it suggests factors that the government should consider for geographical agglomeration of start-ups.

• Journal of Preventive Medicine and Public Health
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• v.39 no.1
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• pp.30-38
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• 2006

Objectives: We examined whether the neighborhood socioeconomic position predicts the smoking rates after adjusting for individual socioeconomic position indicators. Methods: Data were obtained from the 2001 Seoul Health Indicators Survey. The neighborhood socioeconomic position was the residential distribution of the high class (power elites), as measured by the location quotients (LQ) for each administrative dong (district). A high LQ denotes a high neighborhood socioeconomic status. The individual socioeconomic position included education, occupation and income. Age-adjusted smoking rates according to the LQ level were computed with the direct method. The total number of subjects in this study (26,022 men and 28,007 women) was the reference. A multilevel logistic regression analysis was conducted with the individuals at the first level and the neighborhoods at the second level to estimate the odds ratios of smoking with 95% confidence intervals. Results: For men, the age-adjusted smoking rates increased with a decrease in the LQ. For women, the relationship between the age-adjusted smoking rate and the LQ was not clear. The odds of smoking for both genders were greater among those subjects with lower incomes and lower education. The manual occupational class had greater odds of smoking than the non-manual class for the males, while the odds ratio of smoking among females with a manual occupation tended to be lower than those females with a non-manual occupation. For the males, the LQ levels independently predicted smoking after adjustment for individual income. However, this relation between the LQ and smoking in males was explained by full adjustment for the individual socioeconomic position indicators (education, occupation and income). Conclusions: A low level of neighborhood socioeconomic position was associated with higher smoking rates among the men residing in Seoul. This association between the neighborhood socioeconomic position and smoking in men was explained by the individual socioeconomic position. Anti-smoking efforts to reduce geographical inequality in smoking should be directed at reducing the smoking rates between the individuals with different socioeconomic backgrounds in the metropolitan city of Seoul, South Korea.

• Journal of Ecology and Environment
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• v.44 no.3
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• pp.126-142
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• 2020

Background: Most of the Pinus densiflora forests, occupying the largest area, have been restored in South Korea since the 1970s. As young pioneer forests, the succession process is under way. Since the forests are distributed nationwide and are vulnerable to disturbances, the process may differ depending on the geography and/or site conditions. Therefore, we reviewed the direction, the seral communities, and the late-successional species of progressive and disturbance-driven succession nationwide in the cool-temperate zone through meta-analysis and empirical observations. Main text: As a result of a meta-analysis of the direct succession and vertical structure, we found that the P. densiflora forest is in a directionally progressive succession, changing to the broadleaved forest after forming a mixed forest with its overwhelming successor, Quercus species (particularly Q. mongolica and Q. serrata). In dry stands in a relative sense, the Quercus species was favored occupying over 80% of the abundance of the succeeding species. Therefore, in dry stands, it is presumed that Quercus-dominated stage would last for a long time due to the current dominance and long life span, and eventually, it settles as Quercus-broadleaved forest with a site change. Contrary to this, it is presumed that in mesic stands where Quercus species do not occur or have low abundance, the late-successional broadleaved species settle early to form a co-dominant forest with multiple species. Due to geographical limits, the species composition of the two late-successional forests is different. Disturbances such as insect pests and fire retrogressed vulnerable P. densiflora forest for a while. However, it was mostly restored to the Quercus forest and is expected to be incorporated in the pathway of the dry stand. Conclusions: We revealed the succession process of P. densiflora forests according to geography and moisture and found that stand moisture had a decisive effect on the species and abundance of the successor. Although the P. densiflora forest is undergoing structural changes, the forest is still young; so within a few decades, physiognomy is not likely to change. Therefore, the decrease in the forest area may be due to other causes such as disturbances and forest conversion rather than due to succession.

• Journal of muscle and joint health
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• v.4 no.1
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• pp.48-60
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• 1997

This study was undertaken to identify the musculotendinous problems and contributing factors to those problems In students majoring in musical instruments in Korea. The data were collected from March 2, 1996 to March 31, 1996 from 261 music students in various geographical areas. The data were analyzed for descriptive statistics, t-test, chi-square using SPSS $PC^+$ program. The results of this study were as follows : 1. In a questionnaire survey of 261 music students, one hundred twenty five(47.9%) reported having had various musculotendinous symptoms. Twenty seven students among the those who had previous symptoms(21.9%) reported the present symptoms. 2. The experience rates of musculotendinous problems in keyboard players, string players and woodwind players were 50.3%, 48.2%, 33.3% respectively. 3. Most of the students practiced most intensively during their high school years and the musculotendinous symptoms began at the same period. 4. Pain, tenderness and stiffness were the most common symptoms, while paresthesia and motor dysfunction were rare. This indicates that most players had muscle tendinous overuse, while small number had nerve entrapment and motor dysfunction. 5. In past and present symptoms, string players experienced musculotendinous symptoms mainly in both sides of shoulders, lumbar area, left finger, and left wrist, while keyboard players experienced more symptoms in the right wrist, shoulder, fingers than left side. 6. The major contributing factors to the symptoms were weight of instrument, types of instruments, types of daily activities, duration of practice, and playing technique. 7 The most frequent treatment modalities for the symptoms were acupuncture or moxibustion, other alternative therapy such as heat compress and massage. Through this study it was found that the musculotendinous problems might be increased along with their career, due to lack of knowledge about preventive measures and patterns of health behavior seeking alternative modalities rather than professional consultation. Therefore, preventive measures that focus on playing habits such as duration of practice, frequency of rest and position while playing should be developed and taught to the students, their parents, and music educators. Doctors who are interested in this area should attempt to correct the position and posture while playing of the posture. And measures for reduction of loading of instrument weight should also be developed.

• Journal of Conservation Science
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• v.23
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• pp.81-93
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• 2008

The analysis of ancient DNA (aDNA) in paleogenetics has become an increasingly important subject of archaeological, anthropological, biological as well as public interest. In this study, paleogenetic analyses were carried out on the human skeletal remains from a historical cemetery site in Myeongam-ri, Asan, Korea. Archaeological records show that this particular location had been used as a habitation or mortuary site as early as the Bronze Age and up until the Joseon Dynasty. Human remains of twenty individuals out of forty-nine tombs from the Goryeo to Joseon Dynasty were selected for the analysis of this study. In order to identify the genealogy of the population and traditional burial pattern of the cemetery, we conducted comparative analyses of the hyper variable regions (HVRs) in mitochondrial DNA (mtDNA) of each sample. A number of cautious steps were taken at all experimental stages in order to avoid erroneous recombination by the segmental and modern contaminations derived from the researchers. We sequenced segmental amplicons of HVRs andassigned relevant haplogroups according to the sequence polymorphism on the basis of the known mtDNA database. The result shows that diverse haplogroups were unexpectedly present in the small population group of the Myeongam-ri site. This diversity appears to be related to the geographical conditions and archaeological properties of the Myeongam-ri site.

• Journal of Aquaculture
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• v.20 no.4
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• pp.232-238
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• 2007

The distribution of stock density and larvae of Atrina pectinata was examined in Deukryang Bay. Sampling of adult stock was seasonally conducted from 29 stations in the bay in May, August, and November 1995 and February 1996. And the larvae were sampled with interval of 3 to 7 days from 12 stations from July to October 1996. Seasonal abundance of the adult in number and in biomass were the highest in August ($18\;inds./m^2$) and in November ($2,790\;g/m^2$), respectively, at G1 station located in the most inner bay. In frequency distribution of shell height, the mode in May appeared in 10-14 cm group with 62%, and that of the other seasons in $15{\sim}19\;cm$ group. The larvae were also distributed mainly at G1 as the adult were. The larval abundance showed a periodical cycle which seemed to be related to lunar cycle. The highest abundance of the larvae occurred on August 16 with $8\;inds./m^3$, and then decreased continuously. With regard to frequency distribution of larval shell height, the larvae less than $200\;{\mu}m$ occurred from July to October. And the mode in July appeared in small size group ($200{\sim}249\;{\mu}m$) with 38%. These results mean that A. pectinata spawned from July to October, mainly middle July to middle August. The larval distribution showed the same geographical tendency to adult distribution. Both the adult and the larvae mainly distributed in the most inner bay and west area of Deukryang island, where was shallower, warmer, and higher primary productivity than the entrance area of the bay and east area of the island. However, larval abundance of A. pectinata in this study was so low compared to adult biomass. The reason for this unusual phenomenon should be understood with the detail research in future.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.86-93
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• 2015

Recently, the development of Maritime Service Portfolios (MSPs) for the safe navigation of ship has been discussed internationally. For the successful service of the MSPs, first of all, studies for the standardization about the structure and data structure of MSPs should be preceded. Also, it is necessary to evaluate and assess whether the services are effective for safe navigation, and provided data and portrayal methods are proper. However, because great dangers will be accompanied when untested MSPs about their effectiveness and safety are applied in real ship navigation, it is necessary that effectiveness and safety of the MSPs should be proven under various navigational conditions and environments by simulation. In this paper, we propose a 3D navigation simulation system using desktop PC environment, which is proper for evaluating the effectiveness of MSPs. The system consists of three modules which are simulation scenario editor, 3D visualization of navigational environment and 2D navigational equipment. The scenario editor module provides an environment setting for simulation, such as properties, routes and positions of vessels and aids to navigations. It also provides functions to create a scenario for the simulation to operate. Additionally, the 3D visualization module provides 3D navigational environment which shows interplay between geographical and navigational environment based on the created scenario. The 2D navigational equipment module provides visualization functions of various navigational equipment, shows the interaction between ship's navigational equipment and ship's environment. The simulation scenario, in which various kinds of ships are routing in the port, is created by the developed simulation system, and experimented whether this developed system is appropriate to evaluate and assess the MSPs developed by the International Maritime Organization.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.1-21
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• 2021

Panax species have gained numerous attentions because of their various biological effects on cardiovascular, kidney, reproductive diseases known for a long time. Recently, advanced analytical methods including thin layer chromatography, high-performance thin layer chromatography, gas chromatography, high-performance liquid chromatography, ultra-high performance liquid chromatography with tandem ultraviolet, diode array detector, evaporative light scattering detector, and mass detector, two-dimensional high-performance liquid chromatography, high speed counter-current chromatography, high speed centrifugal partition chromatography, micellar electrokinetic chromatography, high-performance anion-exchange chromatography, ambient ionization mass spectrometry, molecularly imprinted polymer, enzyme immunoassay, 1H-NMR, and infrared spectroscopy have been used to identify and evaluate chemical constituents in Panax species. Moreover, Soxhlet extraction, heat reflux extraction, ultrasonic extraction, solid phase extraction, microwave-assisted extraction, pressurized liquid extraction, enzyme-assisted extraction, acceleration solvent extraction, matrix solid phase dispersion extraction, and pulsed electric field are discussed. In this review, a total of 219 articles published from 1980 to 2018 are investigated. Panax species including P. notoginseng, P. quinquefolius, sand P. ginseng in the raw and processed forms from different parts, geographical origins, and growing times are studied. Furthermore, the potential biomarkers are screened through the previous articles. It is expected that the review can provide a fundamental for further studies.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.295-302
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• 2014

Mottled skates, Beringraja pulchra, mainly found in the Yellow Sea were caught by otter trawl at 30 stations from 2002 to 2013 to identify the distribution patterns and ecology of the fish in the eastern Yellow Sea. A total of 442 individuals of mottled skate were caught at the 112 hauls of the total 892 hauls. The fish was widely distributed in the entire survey area in spring and autumn, and mainly caught in the northern offshore in summer and in the southern part in winter. The under-yearlings of the mottled skate were mainly caught in the offshore in spring and autumn. The mottled skates were found at the temperature ranges of $3.8{\sim}14.5^{\circ}C$, and the salinity of 31.2~34.2. The catch data of the fish suggested that water temperature be a critical factor for the distribution with the optimal ranges of $5{\sim}14^{\circ}C$. Salinity and water depth were not critical as much as the water temperature for the distribution of the mottled skates in the Yellow Sea. Also, the annual fluctuations of the fish catch were reviewed using the catch data from korea fisheries cooperative and national statistics from 1991 to 2009.