• Journal of Korea Port Economic Association
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• v.33 no.3
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• pp.139-154
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• 2017

As competition in domestic and overseas ports intensify, new and small domestic ports are realizing certain limitations to independently secure competitiveness. This study collected data over 60 months with five modifications for container and general cargo volume around Gyeongin Port. Short-period (12 months) cargo volume was forecasted, which revealed the need for a middle-to-long-term development plan. First, the hinterland logistics complex of Gyeongin Port is expected to contribute to the coastal maritime facility through the quasi-public system for fishery product transportation and passenger services. It proposes to achieve this by opening channels to and from China for precision machinery, home network systems, LEDs, and machine industry items. second, specializing the ultra-light cargo transport route, and connecting the coastal island areas of the 5 West Sea Islands to Ara Waterway (Integrated Fishery Product Center of the 5 West Sea Islands). Third, on the basis of organic cooperation of government? local government ? port, the incentive and pre-circular support system would be required, and lastly, it shall carry out the adjustment of functions in nearby ports and specialization strategy simultaneously through the integrated operation of the ports in the capital areas.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.623-636
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• 2012

Roundabout is an intersection that allows vehicles to pass through the intersection by circulating the circular traffic island at the center of the intersection. In this study, a comparative analysis was conducted on roundabout at five locations in order to deduce the operational result and financial effect of roundabout and signal intersection. As for the operational result, it was found that roundabout showed improvement effect in the average delay per vehicle compared to that of signal intersection by minimum of 65.6% and maximum of 91.77%. it was found that roundabout showed financial cost-saving effect in the traffic congestion cost compared to that of signal operation by minimum of 58.59% and maximum of 81.69% per year. It can be known from these analysis results that roundabout has significant operational effects under certain amount of traffic volume by allowing vehicles to pass through the intersection in a continuous way without much waiting time and stoppage from signal control.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.52-52
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• 2011

나노필라멘트는 단면직경이 수백 나노미터에서 수십 나노미터 수준인 초극세 장섬유를 말하며, 해도형 복합방사로 얻어진 섬유를 알칼리 감량을 통해 해성분을 용출하여 도성분에 해당하는 나노필라멘트를 얻는다. 이러한 나노필라멘트사는 초극세와 마찬가지로 단위중량당 표면적이 크고, 작은 굴곡반경 및 낮은 굴곡 반발성으로 인하여 일반 합성섬유에 비하여 고가성 및 새로운 기능성을 부여하는 제품에 응용 될 수 있다. 특히 나노필라멘트를 이용한 편물제품으로 경편물은 wiping cloth 등 산업용도에 적용되며, 환편물은 인조피혁 등 의류용으로 사용된다. 나노필라멘트 편물은 원사섬도, 편물의 조직, 밀도 및 중량 등에 따라 분할율과 용출 특성이 상이하므로 후가공 공정에 있어서 감량공정은 매우 중요하다. 또한 나노필라멘트와 같은 세사의 경우 일반사보다 비표면적이 증가하여 동일한 염색조건에서 옅은 색상을 나타낸다. 이로 인해 같은 색상을 위하여 보다 많은 염료를 투입해야 하며, 결과적으로 견뢰도 문제가 발생할 우려가 있다. 이 연구에서는 해도형 나노필라멘트 PET 원사와 일반 PET사를 복합한 2종의 편물을 이용하여 알칼리감량특성 및 3가지 분산염료에 대한 염색성과 견뢰도를 조사하였다. 알칼리 처리조건에 따른 감량률을 측정함으로써 각 편물의 이론 감량률에 도달하는 지점을 확인하고, SEM사진 분석을 통하여 해도사의 감량정도 및 분할특성을 확인하였다. 나노필라멘트 편성물은 염료농도가 증가함에 따라 지속적으로 K/S 값이 증가하였으나, 전체적으로 낮은 K/S값을 얻었다. 또한 염색온도가 110에서 $100^{\circ}C$로 증가함에 따라 K/S값이 감소하였는데, 이는 고온에서 분산염료가 나노필라멘트로부터 일반 PET사로 이염이 더 많이 발생하였기 때문이라고 생각된다. 세탁견뢰도의 경우 양호 또는 우수하였으나, 일광견뢰도의 경우 1등급으로 매우 낮아 이를 개선하기 위한 노력이 향후 진행되어야 할 것이다.

• Animal Systematics, Evolution and Diversity
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• v.21 no.1
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• pp.81-91
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• 2005

A new species of draconematid nematode, Paradraconema jejuense n. sp., is described from the shallow sublittoral coarse sediments of Jeju Island, Korea. Paradraconema jejuense n. sp. is most similar to P. antarcticum Allen and Noffsinger, 1978 in having similar habitus (long slender body) and amphideal fovea (doubled elongate spiral in male and circular spiral in female), but is distinguished by the following characteristics: larger number of posterior sublateral adhesion tubes (10 in male and 11-12 in female) and subventral adhesion tubes (16 in male and 17-18 in female), fewer cephalic acathiform setae on rostrum (a pair of small cephalic acathiform setae in both sexes), the absence of eye-spots, and the presence of a differentiated lateral field in mid-body region. This is the first taxonomic report on Paradraconema species from Korea.

• Microbiology and Biotechnology Letters
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• v.52 no.1
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• pp.102-104
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• 2024

Massilia sp. KACC 81254BP, isolated from a landfill on Jeju Island, Republic of Korea, possesses the capability to degrade polyhydroxyalkanoates (PHAs). The genomic analysis of strain KACC 81254BP consists of a circular chromosome comprising 5,028,452 base pairs with a DNA G+C content of 64.6%. This complete genome consists of a total of 4,513 genes, including those encoding the PHA degradation enzyme (PhaZ). This study offers valuable genomic insights into the enzymes responsible for degrading polyester plastics.

• Economic and Environmental Geology
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• v.44 no.2
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• pp.135-152
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• 2011

Nitrate concentrations in springs at the southern slope of Jeju Island were predicted using multiple linear regression (MLR) of spatial variables including hydrogeological parameters and land use characteristics. Springs showed wide range of nitrate concentrations from <0.02 to 86 mg/L with a mean of 20 mg/L. Spatial variables were generated for the circular buffer when the optimal buffer radius was assigned as 400 m. Selected regression models were tested using the p values and Durbin-Watson statistics. Explanatory variables were selected using the adjusted $R^2$, Cp (total squared error) and AIC (Akaike's Information Criterion), and significance. In addition, mutual linear relations between variables were also considered. Small portion of springs, usually <10% of total samples, were identified as outliers indicating limitations of MLR using circular buffers. Adjusted $R^2$ of the proposed models was improved from 0.75 to 0.87 when outliers were eliminated. In particular, the areal proportion of natural area had the greatest influence on the nitrate concentrations in springs. Among anthropogenic land uses, the influence of nitrate contamination is diminishing in the following order of orchard, residential area, and dry farmland. It is apparent quality of springs in the study area is likely to be controlled by land uses instead of hydrogeological parameters. Most of all, it is worth highlighting that the contamination susceptibility of springs is highly sensitive to nearby land uses, in particular, orchard.

• Journal of Korean Society of Transportation
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• v.31 no.6
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• pp.43-52
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• 2013

A roundabout is a form of circular intersection in which traffic travels counterclockwise around a central island and in which entering traffic must yield to circulating traffic. It has been known that a roundabout provides substantially better operational and safety characteristics than other intersections including rotaries. Recently, a roundabout has started to be constructed due to its efficiency, safety, and other advantages of a roundabout comparing other intersections in Korea. However, there has been no guideline to be used to decide appropriate intersection types considering given conditions of the intersections. To solve this problem, the guideline with traffic volume to choose the suitable intersection types was developed based on analysis results using the SIDRA software which is generally used to analyze operational effects of roundabouts. It was found that a roundabout is more efficient than signalized intersection when the traffic volume is between 125 and 450 veh/h on one lane road and roundabout is not recommended when there are more than 30% left turn traffic. The optimal traffic volume provided in this research will be usefully used in planing and designing roundabouts in Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.3
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• pp.301-311
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• 1999

The investigation to evaluate the possible effects of fish behaviour on acoustic target strength was carried out during the 1997 and 1998 hydroacoustic-demersal trawl surveys in the southern waters of Korea.The swimming speed and the target strength of individual, acoustically resolved fished swimming through the sound beam were measured using the split-beam tracking method on board R/V Kaya.The results obtained can be summarized as follows:1. The alongship and athwartship angles between -3dB poionts of a hull mounted 38 kHz split beam tranducer used in these surveys was >$3.76^{\circ}\;and\;6.74^{\circ}$ respectively, and the equal energy contour obtained from the measured beam pattern showed approximately the circular pattern. 2. The swimming speed measured off the south coast of Sorido in 23 January 1997 ranged 0.10 to 0.80 m/s with the average swimming spped of 0.36 m/s, and the target strength ranged -64.8 to -31.7 dB with the average target strength of -52.7 dB. The most dominant species sampled in this survey area were Japanese scaled sardine, Sardinella zunasi and Konoshiro gizzard shad, Konosirus punctatus, respectively.3. The swimming speed measured off the east coast of Kojedo in 24 March 1997 ranged 0.10 to 1.10 m/s with the average swimming speed of 0.40 m/s, and the target strength ranged -64.8 to -51.5 dB with the average target strength of -59.2 dB. The most dominant species sampled in this survey area were Swordtip squid, Photololigo edulis, Konoshiro gizzard shad and Japanese flying squid, Toddarodes pacificus, respectively and the swimming activity of these species seems to be controlled at speeds between 0.20 and 0.60 m/s. 4. The swimming speed measured the south coast of Kojedo in 25 March 1997 ranged 0.10 to 1.40 m/s with the average swimming speed of 0.51 m/s and the target strength ranged -64.3 to -47.7 dB with the average target strength of -55.1 dB. The most dominant species sampled in this survey area were Swordtip squid, Blotchy sillage, Sillago maculata and japanese scaled sardine, respectively and the swimming activity of these species seems to be controlled at speeds between 0.20 and 0.70 m/s.5. The swimming speed measured during morning twilight in the southeastern water of Cheju Island in 11 July 1998 ranged 0.20 to 1.0 m/s with the average swimming speed of 0.53 m/s, and the target strength ranged -65.0 to -47.0 dB with the average target strength of -57.1 dB. The most dominant species sampled in this survey area were Swordtip squid, Black scraper, Thamnaconus modesutus and japanese flying squid, respectively and the tile angle ranged$ +28^{\circ}\;to\;+2^{\circ}$ with the average tilt angle of -8.1$^{\circ}$ showing the downward migration.

• Journal of Conservation Science
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• v.33 no.3
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• pp.181-188
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• 2017

A total of 16 precious archaeomagnetic dating data were obtained from various historic sites including fired soils from eight archaeological sites on Jeju Island. We researched the measurement results of 12 pieces of data from before the Common Era (BCE), and four pieces of data from after the Common Era. First, the BCE data could be divided into three groups (A, B, and C) based on the difference in the archaeomagnetic data. By comparing the data accumulated in other parts of Korea and referring to the archaeological years, the order of the groups was as follows: A group (Bronze Age~Early Iron Age) ${\rightarrow}$ B group (Early Iron Age when the circular rim eomtodae pottery was excavated) ${\rightarrow}$ C group (Early Iron Age when triangulated rim jeomtodae pottery was excavated), with A group being the earliest data group and C group being the latest data group. In addition, the data after the Common Era could be used to determine the archaeomagnetic dating of the archaeological sites. Through the archaeomagnetic dating of Jeju's archaeological sites for the BCE period, the relative order of the relics was determined, and for the period after the Common Era, the absolute age of the historic sites was obtained. They are expected to be used diversely in the chronological study of Jeju.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.615-627
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• 2021

The Baekildo fault, a dextral strike-slip fault developed in Baekil Island, Goheung-gun, controls the distribution of tuffaceous sandstone and lapilli tuff and shows a complex fracture system around it. In this study, we examined the spatial variation in the geometry and connectivity of the fracture system by using circular sampling and topological analysis based on a detailed fracture trace map. As a result, both intensity and connectivity of the fracture system are higher in tuffaceous sandstone than in lapilli tuff. Furthermore, the degree of the orientation dispersion, intensity, and average length of fracture sets vary depending on the along-strike variation in structural position in the tuffaceous sandstone. Notably, curved fractures abutting the fault at a high angle occur at a fault bend. Based on the detailed observation and analyses of the fracture system, we conclude as follows: (1) the high intensity of the fracture system in the tuffaceous sandstone is caused by the higher content of brittle minerals such as quartz and feldspar. (2) the connectivity of the fracture system gets higher with the increase in the diversity and average length of the fracture sets. Finally, (3) the fault bend with geometric irregularity is interpreted to concentrate and disturb the local stress leading to the curved fractures abutting the fault at a high angle. This contribution will provide important insight into various geologic and structural factors that control the development of fracture systems around faults.