• Title/Summary/Keyword: transition region

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Characteristics of Korean Inshore Fishing Boats (한국(韓國) 연근해어선(沿近海漁船)의 특성(特性))

  • Keuck-Chun,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.8 no.1
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    • pp.67-94
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    • 1971
  • Korean fisheries industry holds 57,255 boats amounting to 269,079 tons in gross as of the end of 1967. The boats of the size under 30G.T., about sixty-two per cent of the total in tonnage, are utilized in coastal and their contribution to the total production of Korean fisheries industry is estimated at over seventy-five percent. Hull forms and construction method of them are partly in transition stage to the western tradition from the oriental tradition, which employs the chine-type straight-framed section, and tick and wide wooden planking fastened on naturally bent timber frames. And only about a half of them are mechanized. About fifty-seven per cent, 7,525 boats amounting to 91,751 gross tons, of the coastal and inshore fishing boats are those of the size ranging 5G.T. to 30G.T., which are engaged mostly in draft-and gill-netting, angling, longlining, anchovy seining, squid fishing and set-netting. The important fishing boats forming main structure of the inshore fishing fleets can be classified as 5G.T.-class multi-purpose boats, 10G.T.-class angling/longlining boats and 20G.T.-class drift-/gill-netters mostly utilized in the east-sea, 15G.T.-class anchovy seiner in the south-sea-sea, 20G.T.- and 28G.T.-class stow-netters in the west sea. Each of the three sea regions, east, south, and west, of Korean water has distinctly different characters from one another in topography, geology and sea aspects, and consequently in marine resources, fishing grounds and fishing tactics desired. Hence, the finishing boats in each sea region have also their own characters in hull form, structural features, deck design and equipments. In this report, analyzing the characteristics of the existing inshore fishing boats ranging 5G.T. to 30G.T. in size from view points of naval architecture and engineering, the author made an integrated investigation of their characteristics, covering size and principal dimensions, hull form, deck design, structural features and mechanization, in close connection with the natural circumstances of Korean water and local techno-socio-economic problems, and, finally, made some suggestions for the rational improvement or modernization of the inshore fishing boats. Further details of the characteristics of Korean inshore finishing boats are referred to the drawings of them compiled by the author and given in the reference[23] listed at the end of this report.

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A Research on the State of Korean Seafood Marketing at the Colonial Period - Focused on the West Coast - (일제강점기의 수산적 유수실태에 관한 고찰 -서해안 지역을 중심으로-)

  • 김수관;두정완;윤영선
    • The Journal of Fisheries Business Administration
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    • v.35 no.1
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    • pp.133-168
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    • 2004
  • The purpose of this study is to examine the state and characteristic of seafood marketing in Korean West Coast during the colonial period ruled by Japan. To accomplish the purpose, we tried to set the fisheries statistical database by reviewing of $\boxDr$Statistical Annual Report of Chosun Chongdokbu$\boxUl$ and $\boxDr$Official Report of Chosun Chongdokbu$\boxUl$. A trend analysis was carried out with the data. Also, by reviewing of articles related to the state of seafood marketing via $\boxDr$Daehan Maeil Newspaper$\boxUl$, $\boxDr$Maeil Newspaper$\boxUl$ issued at the period, we could find out some meaningful findings which backed up the statistics in realistic facts. For numbers of businessman in seafood marketing, it was clear that the number of Japanese businessmen increased more quickly than that of Korean compared with other sphere of fisheries. That means Japanese grasped Korean seafood market in a short time. In price of seafood in terms of cities, Kunsan was comparatively higher than Incheon and Mokpo. In price of seafood in terms of species, ‘Snapper’ was mostexpensive, and ‘Mackerel Pike’, ‘Anchovy’, ‘Mullet’, ‘Eel’, ‘Flatfish’ followed in that order. In price of a species in terms of ‘Yellow Croaker’, which was famous in West Sea, ‘Croaker with salt’ was more expensive than dried and fresh one. For the transition trend of number of fish market, we could ascertain that the number of market increased until 1919, however, it decreased slowly from 1932. That means Japanese government went to war against China from 1931. Of the West Coast, the number of fish market in Chungnam province was most high, but that of Chonbuk outrun from 1940. At that time, the number of fish market in West Coast reached to 34% out of that of whole country. In 1919, the proportion of seafood sales amount of West Coast neighboring provinces, such as Kyunggido, Chungnam, and Chonbuk, was 23% of whole country which rose to 28% in 1929, and 29% in 1939. Therefore, we could assure that seafood marketing was very active at that time in the region. When we consider the trend of seafood export at the main ports of West Coast, in 1910's, the export through Mokpo and Inchon port was very live but that of Kunsan was very tiny. However, in 1920's, the export amount of Inchon port did not much change, but that of Mokpo decreased, whereas, that of Kunsan increased. In the early and middle of 1910' s which was around beginning of Japanese ruling period, we realized that the imperialist Japan was very eager in political efforts to enhance the mind of seafood's quality improvement through the opening of several fisheries competitive shows and fairs.

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A Study on the Plan-type of Pit-dwelling site in Joseon dynasty - Focusing on the Pit-dwelling of Seoul·Gyeonggi region - (조선시대 수혈주거지의 평면유형 연구 -서울·경기지역 수혈주거지를 중심으로-)

  • Seo, Ji-Eun;Hong, Seung-Jae
    • Journal of architectural history
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    • v.24 no.3
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    • pp.43-56
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    • 2015
  • Researches on the pit dwellings in the Joseon Dynasty era have been constantly conducted in the archeology field since the beginning of the 2000s. Most of the related researches in the past have been on the classification and chronological record of dwelling types in archeology, but architectural researches on the dwelling history that is connected from the prehistoric age to the Joseon Dynasty era are insufficient. There are no big differences between the excavated pit dwellings of the Joseon Dynasty era and those of the prehistoric age, so pit dwellings were considered to have been used as dwellings for common people until the Joseon dynasty era. This fact is confirmed by the frequency and density of pit dwellings. In this research, what space composition of the pit dwellings that are equipped with the Korean floor heating system is shown according to the plan types was examined and the development and transition process from pit dwellings to Folk houses were analyzed and their correlations with the Folk houses of the Joseon Dynasty era were examined. The Folk house form did not start with the form of the house on the ground but originate from the introduction of Ondol, the Korean floor heating system, to pit dwellings. As the Korean floor heating system is used, the room and kitchen space are composed in the pit dwelling, and the kitchen is expanded to the one that separates the fireplace for cooking to avoid heating that is unnecessary for the summer season. As the size of the dwelling was getting bigger, the division of the space is made by the pillars that support the interior space. Also, the dwelling is expanded into a single row house and a double row house according to the progress direction of Ondol. In other words, the pit dwellings in the Joseon Dynasty era develops with making up diverse floors through the combination and expansion of Ondol and kitchen according to the dweller's convenience and life style and surrounding environment. This research is significant in the sense that it helps understand the formation and development process of our traditional Folk houses and fills the gap between the pit dwellings, which have been dealt with inadequately, and traditional Folk houses in the Korean dwelling history.

Optical Properties of Cdlnsub 2Ssub 4 and Cdlnsub 2Ssub 4 : $CdIn_2S_4$$CdIn_2S_4 : Co^{2+}$Single Crystals ($CdIn_2S_4$$CdIn_2S_4 : Co^{2+}$ 단결정의 광학적 특성)

  • Choe, Seong-Hyu;Bang, Tae-Hwan;Kim, Hyeong-Gon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.5
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    • pp.296-302
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    • 1999
  • $CdIn_2S_4 and CdIn_2S_4 : Co^{2+}$ singlecrystals of thenormal spinel structure were grown by the C.T.R. method. The optical energy band structure of these compounds had a indirect band gap at the fundamental optical absorption band edge. The direct and the indirect energy gaps are found to be 2.325 and2.179eV for $Cdln_2S_4$ , and 2.303 and 2.169eV for $CdIn_2S_4 and CdIn_2S_4 : Co^{2+}$ at 5K, respectivly. The fundamental absorption band edge of these single crystals shift to a shorter wavelength region with decreasing temperature, and the temperature dependence of the optical energy gaps in these compounds satisfy Varshni equation. The Varshni constants$\alpha and \beta$ of the direct energy gap are given by $13.39{\times}10_{-4}eV/K$ and 509 K for $Cdln_2S_4$ and $29.73{\times}10_{-4} eV/K$ and 1398K for $CdIn_2S_4 and CdIn_2S_4 : Co^{2+}$. The Varshni constants ${\alpha}and {\beta}$ of the indirect energy gap are given by 9.68${\times}10^{-4}$ eV/K 308K for $Cdln_2S_4$ and $13.33{\times}10_{-4}eV/K$ and 440K for $CdIn_2S_4 : Co^{2+}$ respectivly. The impurity optical absorption peaks due to cobalt dopant are observed in $CdIn_2S_4 : Co^{2+}$ single crystal. These impurity optical absorption peaks can be attributed to the electronic transitions between the split energy levels of $Co_{2+}$ ions located at $T_d$ symmetry site of $Cdln_2S_4$ host lattece.

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Suggestions for Safety Improvement of CNG Bus Based on Accident and Failure Analysis (CNG버스 사고원인 분석에 근거한 안전성 향상 방안에 대한 연구)

  • Yoon, Jae-Kun;Yoon, Kee-Bong
    • Journal of the Korean Institute of Gas
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    • v.12 no.2
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    • pp.69-76
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    • 2008
  • Three failure cases of CNG composite vessels were reported since after January 2005. The 1st and 2nd accidents were indebted to vessel defect and installation mistake. The 3rd was caused by gas leak at pipe connections. In this paper various aspects were studied based on information of the three failure analysis, which must be improved for better safety of the CNG bus system. Overpressure region caused by vessel explosion was theoretically predicted and also assessed by PHAST program. Explosion of 120 l vessel under 20 MPa is equivalent to 1.2 kg TNT explosion. The predicted value by PHAST was more serious than theoretical one. However, actual consequence of explosion was much less than both of the predicted consequences. Since the CNG vessel was designed by the performance based design methodology, it is difficult to verify whether the required process and tests were properly conducted or not after production. If material toughness is not enough, the vessel should be weak in brittle fracture at early in the morning of winter season since the metal temperature can be lower than the transition temperature. If autofrettage pressure is not correct, fatigue failure due to tensile stress during repeated charging is possible. One positive aspect is that fire did not ocurred after vessel failure. This may be indebted to fast diffusion of natural gas which hindered starting fire.

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Optical transition dynamics in ZnO/ZnMgO multiple quantum well structures with different well widths grown on ZnO substrates

  • Li, Song-Mei;Kwon, Bong-Joon;Kwack, Ho-Sang;Jin, Li-Hua;Cho, Yong-Hoon;Park, Young-Sin;Han, Myung-Soo;Park, Young-Sik
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.121-121
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    • 2010
  • ZnO is a promising material for the application of high efficiency light emitting diodes with short wavelength region for its large bandgap energy of 3.37 eV which is similar to GaN (3.39 eV) at room temperature. The large exciton binding energy of 60 meV in ZnO provide provides higher efficiency of emission for optoelectronic device applications. Several ZnO/ZnMgO multiple quantum well (MQW) structures have been grown on various substrates such as sapphire, GaN, Si, and so on. However, the achievement of high quality ZnO/ZnMgO MQW structures has been somehow limited by the use of lattice-mismatched substrates. Therefore, we propose the optical properties of ZnO/ZnMgO multiple quantum well (MQW) structures with different well widths grown on lattice-matched ZnO substrates by molecular beam epitaxy. Photoluminescence (PL) spectra show MQW emissions at 3.387 and 3.369 eV for the ZnO/ZnMgO MQW samples with well widths of 2 and 5 nm, respectively, due to the quantum confinement effect. Time-resolved PL results show an efficient photo-generated carrier transfer from the barrier to the MQWs, which leads to an increased intensity ratio of the well to barrier emissions for the ZnO/ZnMgO MQW sample with the wider width. From the power-dependent PL spectra, we observed no PL peak shift of MQW emission in both samples, indicating a negligible built-in electric field effect in the ZnO/$Zn_{0.9}Mg_{0.1}O$ MQWs grown on lattice-matched ZnO substrates.

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A Small-Angle Neutron Scattering Study for Sizes and Structures of Micelles and Vesicles Formed in Aqueous Solutions of Mixed Surfactants ADS/OTAC (ADS/OTAC 혼합 계면활성제 수용액에서 형성된 마이셀과 층막구형체의 크기 및 구조에 대한 작은 각 중성자 산란 연구)

  • Kim, Hong-Un;Lee, Jin-Kyu;Lim, Kyung-Hee
    • Applied Chemistry for Engineering
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    • v.16 no.2
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    • pp.231-237
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    • 2005
  • The sizes and structure of micelles and vesicles formed in ammonium dodecyl sulfate (ADS)/octadecyl trimethyl ammonium chloride (OTAC) mixed aqueous solutions were analyzed by small-angle neutron scattering. In micellar regions of pure ADS and OTAC aqueous solution, the spherical micelles were formed at given concentrations and their sizes were 40 and $61{\AA}$, respectively. The structure transition of pure micelles occurred above 300 mM due to the constancy of the intermicellar distance above 250 mM. The coexisting region of mixed micelles and vesicles in phase diagram of mixed system was also assured. It was investigated that vesicle formed spontaneously took a bilayer structure. The lamellar thickness of vesicles decreased with increasing concentration of vesicle samples. However, the size could not be determined for mixed micelle and vesicle above 100 nm due to limitation of low q ranges. Finally, The 9 mM solution of ADS mole fraction 0.9 (${\alpha}$=0.9) showed bilayer structure compared to phase diagram classified into mixed micelle.

Radiological Safety Assessment for KAERI Incineration Plant on the Basis of Trial Burn Results (시험소각결과에 기준한 한국원자력연구소 소각시설의 방사학적 안전성 평가)

  • Yang, Hee-Chul;Kim, Bong-Hwan;Kim, Chang-Hee;Park, Won-Man;Jeong, Myung-Soo
    • Journal of Radiation Protection and Research
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    • v.23 no.2
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    • pp.109-114
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    • 1998
  • Radiological safety for the conventional operation of Demonstration-Scale Incineration Plant (DSIP) was assessed on the basis of the results of trial burns using the simulated and real radioactive wastes. Radiation dose assessments for routine releases on an annual basis as well a several severe accidental releases on a short-term basis (2h) revealed that there would be no significant environmental impact when low-level waste Is incinerated in DSIP. For semivolatile radioactive cesium species, expected emission concentrations slightly exceeded 10% of maximum permissible concentration. Removal characteristics of the bag filter for condensed-phase cesium species was investigated by the trial burns of simulated waste with inactive cesium tracer. In the off-gas before passing through bag filter, distributions of condensed cesium species in the transition size ranging between the diffusional and inertial region are less than 5%. The overall collection efficiency of the bag filter for cesium species was higher than 99.9%, showing enough decontamination capability as a primary filter for the low-temperature dry off-gas system in radwaste incineration plant.

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Improvement and Evaluation of Resident Satisfaction Degree on Rural Village Development Project by Rural Territory (지역유형을 고려한 농촌마을종합개발사업의 주민평가 및 개선방안)

  • Choi, Young-Wan;Park, Jeong-Won;Yoon, Yong-Cheol;Kim, Young-Joo
    • Journal of agriculture & life science
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    • v.45 no.6
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    • pp.227-235
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    • 2011
  • This research had selected current rural village development projects with the representative meaning of rural regional development projects in order to analyze results of projects and various policies of the government to enhance the quality of resident life and to develop rural regions. For the analysis, this research had selected 2 districts of the case study in Gyeongnam-province and Jeonnam-province, respectively. In the result of the satisfaction analysis on the projects, it was considerably difficult to analyze satisfaction degree by using a clear distinction of each region type when promoting overall project. However, this research confirmed that there were some differences about residents' understanding of the project and satisfaction degree in the process of projects according to the regional characteristics (rural and mountain areas). In general, two districts' residents of rural areas expressed relatively more negative feedbacks in process of the project compared to two district residents of mountain areas. This research suggested that it is needed to have residents' understanding of the project, a restoration of village community spirit to help each other and to cooperate, fostering a desirable leader, establishing effective village regulations, transition into an open and inclusive attitude, promoting rural village development project, and realization of the operating method in order to have an amicable project process in the future.

Efficient Methodology in Markov Random Field Modeling : Multiresolution Structure and Bayesian Approach in Parameter Estimation (피라미드 구조와 베이지안 접근법을 이용한 Markove Random Field의 효율적 모델링)

  • 정명희;홍의석
    • Korean Journal of Remote Sensing
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    • v.15 no.2
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    • pp.147-158
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    • 1999
  • Remote sensing technique has offered better understanding of our environment for the decades by providing useful level of information on the landcover. In many applications using the remotely sensed data, digital image processing methodology has been usefully employed to characterize the features in the data and develop the models. Random field models, especially Markov Random Field (MRF) models exploiting spatial relationships, are successfully utilized in many problems such as texture modeling, region labeling and so on. Usually, remotely sensed imagery are very large in nature and the data increase greatly in the problem requiring temporal data over time period. The time required to process increasing larger images is not linear. In this study, the methodology to reduce the computational cost is investigated in the utilization of the Markov Random Field. For this, multiresolution framework is explored which provides convenient and efficient structures for the transition between the local and global features. The computational requirements for parameter estimation of the MRF model also become excessive as image size increases. A Bayesian approach is investigated as an alternative estimation method to reduce the computational burden in estimation of the parameters of large images.