• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.296-302
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• 1991

Compression wood and opposite wood formed in a branch of Taxodium distichum Rich. is described and compared in qualitative and quantitative anatomical aspects. The qualitative features of compression wood appeared to differ from those of opposite wood in very gradual tracheid transition from earlywood to latewood, roundish tracheid shape on cross surface, tracheid tip distortion on radial surface, and existence of intercellular spaces and helical cavities. In quantitative features, compression wood tracheids showed shorter lengths than opposite wood. The ray density and the number of uniseriate rays were greater in compression wood than in opposite wood but the height of uniseriate rays in compression wood was smaller than in opposite wood.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.2
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• pp.59-69
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• 1989

The goby genus Tridentiger of Korea is reviewed and keys to following four species of the genus Tridentiger are provided for T. trigenocephalus, T. obscurus, T. nudicervicus and T. brevispinis. Among them, T. brevispinis is reported for the first time from Korea with the descriptions and illustrations of other three species of this genus in this paper. The external features of T. brevispinis are very similar with those of T. obscurus, however T. brevispinis is distinguished from T. obscurus by having the shorter 3rd dorsal spine, lesser number of gill rakers and longer intestine length. T. obscurus lives in the river mouth and esturaies around the coast of Korea, while T. brevispinis is collected from only the fresh water area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.387-408
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• 1986

Available information on the family Gobiidae of Korea is summarized from the literatures and specimens collected during the period from 1980-1985 in the southern part of Korea. Thirty three species belonging to 23 genera were identified from 73 localities in Korea, and among them 3 species are reported for the first time from Korea with their description and illustrations: Micropercops dabryi borealis Nichols, 1930, Acentrogobius masago (Tomiyama, 1936), and Apocryptodon madurensis (Bleeker, 1849). Both Luciogobius grandis Arai and Mugilogobius abei (Jordan et Snyder) previously recorded in Korea, but not included in the list by Chong, 1977 are included in this list. Rhinogobius bedfordi is considered a junior synonym of R. brunneus. The occurrence of Acanthogobius ommaturus and Gobius caninus from Korea are open to question for lack of evident records. The family of Gobiidae of Korea includes 46 species belonging to 30 genera which are divided into four subfamilies, Eleotrinae, Gobiinae, Gobionollinae, and Tridentigerinae by Miller in 1973. A key to genera is provided together with synonymies, distributions and materials observed for the gobiid fishes of Korea.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.253-263
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• 2020

Since the birth of the Ethereum in 2015, various decentralized applications (DApp) based on blockchain smart contract technology have appeared. However, CryptoKitty's case showed instability in terms of performance and scalability in real-world service environments. To solve this, a blockchain platform that developed a high transaction per second (TPS) has appeared, but there have been no environments and services to test it. Therefore, this paper intends to design and develop a game that can record the contents of all games on the chain and verify the performance and scalability of the blockchain platform through oversized transactions. The developed game generated a total of 6.3 million blocks and 8.9 million transactions through by 682 and verified the improved performance and scalability of the existing platform. Additionally, the maximum TPS was measured at 1,309 during the test period. In the future, it is expected that performance and scalability can be compared in a realistic environment through the method presented in this paper.

• Journal of Labour Economics
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• v.34 no.2
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• pp.79-107
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• 2011

This study investigates the status of English scores in the Korean labor market. We provide an empirical explanation of how English scores affect labor performances in Korea. Specifically, we focus on the effects of TOEIC scores on college graduates' job opportunity and wage premium. Our empirical tests for TOEIC scores are implemented in three dimensions: (1) Screening effects (2) Signaling effects (3) Wage effects. The results are as follows. First, we find the positive correlation between TOEIC scores and job opportunities, which implies that TOEIC scores play an important role in employee selection process. Second, our tests give the same results when it comes to job seeker's use of TOEIC scores as signaling instrument. That is, high TOEIC scores have positive signaling effects in the labor market. However, there also exists disadvantage effect of low TOEIC scores, in that job applicants with TOEIC scores below certain level are even more disadvantageous than those with no TOEIC scores. Finally, wage premium of TOEIC scores are found, even when other variables (e.g. GPA) are controlled or we use the instrumental variable estimate.

• 한국해양학회지
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• v.15 no.2
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• pp.123-128
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• 1980

Variabilities of tidal range at Inchon were described based on observed values. Relationships between tidal ranges and harmonic costants of tide were also examined. Fortnightly variation is predominant and its range is 571.3cm. Mean of maximum spring range(ΔH/sun max/) is 887.2cm and that of minimum neap range(ΔH/sun min/) is 315.9cm. Mean tidal range(ΔH) is 634.3cm. Diurnal inequality is shown about 141cm on an average and monthly inequality is also shown about 100cm. Yearly inquality appears with a range of about 35cm, maxima in March and September, and minima in June and December. There may exist 18 1 years periodicity with a range of about 45cm. There are some relationships between ridal ranges and amplitudes of M$\_$2/ and S$\_$2/, such as ΔH=2.172 H$\_$m/, ΔH$\_$max/=3.043 H$\_$m/, ΔH$\_$min/=1.071 H$\_$m/, ΔH$\_$max/=2.198 (H$\_$m/ + H$\_$s/), and ΔH$\_$min/=1.740 (H$\_$m/ - H$\_$s/).

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.1-8
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• 2017

The U.S. NRC establishes a radiological criteria with regard to restricted or unrestricted use of nuclear plant site after decommissioning in NUREG-1757. According to this, a nuclear plant site can be released in a restricted way or unrestricted way only if a licensee demonstrates that the dose criteria is fulfilled after the site decontamination and remediation. In order to prove compliance with the radiological criteria of site release, LTP(License Termination Plan) must include the site release criteria, site characterization, final survey plan with major radionuclides and DCGL(Derived Concentration Guideline Levels), etc. Based on the decommissioning case of Rancho Seco nuclear power plant in the United States, this paper analyzed a method of setting the DCGL that can be applied to Kori NPP Unit 1 which will be permanently disabled in 2017.

• Korean Journal of Food Science and Technology
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• v.5 no.4
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• pp.240-248
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• 1973

Reduction of penta-O-acetyl-myo-inosose-2 by catalytic hydrogenation and with sodium-amalgam was carried out in alcohol solution of pH $3{\sim}4$. The former reduction product was axial-alcohol, and the latter equatorial-alcohol. On reduction of penta-O-acetyl-DL-epi-inosose-2 with sodium borohydride and sodium-amalgam in the previous condition, ax.-alcohol and eq.-alcrhol have been obtained. The synthesis of various inositol-p-hydroxybezoate are described. The esters have been characterized by paper chromatography and saponification, and their antimicrobial activities on some microbes were tested for the application of food industry. As the result, it was found that the antimicrobiol activity of epi-inositol ester was superior to its analogues.

• Animal Systematics, Evolution and Diversity
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• v.7 no.2
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• pp.179-188
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• 1991

In order to determine the taxonomic status of Apodemus agrarius chejuensis from Cheju island in Korea, three hundred and eleven samples of eight subspecies of striped field mice (subspecies, agrarius, ningpoensis , pallidior, chevrieri, insulaemus, manchuricus, coreae, and chejuensis of A. agrarius Pallas) in Asia, collected from Turkey , China, Taiwan, , Manchuria, and Koarea, were used. Four external and 27 cranial characters were measured and their measurements were utilized for multivariate analyses such as cluster, principal component, and discriminant analyses. Four forms were revealed . A largest-size from was chejuensis, whereas a large-size form was cheverieri. A medium -size from and a small-size from were coreae and other five subspecies (agrarius , ningpoensis, pallidior, insulaemus, and manchuricus) , respecitvley, but their differences were clinal. A discontinuous gap was revealed between chejuensis (a largest-size from) and six subspecies ( a medium-size from and a small-size form) Although chejuensis appeared to be a distinct species, it is concluded that molecular analyses are necessary in order to describe it as a new species.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.412-412
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• 2011

CI(G)S계 태양전지는 화합물 반도체로서, 우수한 광 전류 변환 효율을 보이며, 광조사 등에 의한 열화가 없어 유망한 태양전지로 인정받고 있다. CI(G)S계 태양전지를 구성하는 흡수층을 제조하는 방법은 진공 기반의 공증착법 및 스퍼터-셀렌화법이 대표적이며, 액상의 전구체 물질을 도포하고 이를 고온 열처리하는 용액공정법도 최근 많은 연구가 이루어지고 있다. 진공 증착법은 고효율의 흡수층을 제조할 수 있고 상용화에 적합한 방법이다. 그러나 고가의 진공 장비를 이용하는 진공증착법은 원가 절감 관점에서 한계를 지니고 있어, 미래의 저가 공정 실현을 위해 용액 기반 흡수층 제조법도 다양한 접근법으로 연구되고 있으며 현재까지는 진공공정에 비해 상대적으로 낮은 변환효율이 큰 문제점으로 인식되고 있다. 용액 공정에서 전구체 물질의 코팅법으로는 spray법, spin coating법, drop-casting법, doctor-blade법 등이 있으며, 이들 중 양산 공정에 실용화되기 가장 적합한 것으로 보이는 방법으로는, 화합물 나노입자 페이스트를 기재 상에 doctor blade 법으로 코팅한 후에 이를 열처리하여 흡수층을 제조하는 방법을 들 수 있다. 이러한 방법은 균일한 흡수층을 저비용으로 제조할 수 있는 장점은 있지만, 전구체로 사용하는 화합물 나노입자들이 화학적 및 열적으로 매우 안정한 물질이므로, 최종 흡수층에서 큰 결정을 얻기 어렵고, 그 결과 효율이 낮아지는 단점이 있다. 따라서, 치밀하고 조대한 grain 형성을 위하여 CISe 균일한 나노입자를 합성하고 셀레늄을 포함하는 용액을 추가로 도포하여 열처리 공정에서 Se의 손실을 막아 입자를 성장시키는 방법과 In-Se 균일한 나노입자를 합성한 후 Cu, Se이 포함된 용액을 도포하여 코어-쉘 (InSe/CuSe)을 제작하고 이를 Se 분위기하 열처리 하여 흡수층의 결정성을 증진시키고자 하였다. 또한 다양한 방법으로 제작한 CuInSe2 나노입자로 잉크를 제작하여 닥터블레이드 공정을 적용하여 박막을 제작하고 소자 적용성을 평가하였다.