• Journal of the Economic Geographical Society of Korea
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• v.25 no.3
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• pp.281-298
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• 2022

The COVID-19 pandemic has so far given the world a great shock and fear that cannot be compared to other infectious diseases, and local economies are experiencing a serious economic crisis accordingly. This paper examines the regional characteristics of economic recession and resilience due to the COVID-19 pandemic, focusing on the employment fluctuations in 85 cities nationwide. Although the overall trend is in line with national employment indicators, there are some differences in the shock response and the recovery of employment in individual cities. The difference between cities is somewhat greater in the resilience of the recovery stage than the resistance, which is the shock-response stage. In terms of resilience, cities in the capital area have relatively good condition compared to cities in the non-capital area. The weak resilience of large cities such as Seoul, which has a high population density, can be explained to be the effect of the COVID-19 pandemic of infectious diseases. Regarding the economic structure of the city, the ratio of service and sales workers, wholesalers and retailers, and food and lodging businesses are analyzed as valid explanatory variables for the resilience of cities.

• The Journal of Engineering Geology
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• v.32 no.1
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• pp.13-26
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• 2022

Calcite twins were analyzed in six oriented samples of the Pungchon limestone, Joseon Supergroup, to reconstruct the paleostress field. The orientations of c-axis of calcite and e twin plane were measured along with the average thickness and numbers of twins, and the widths of calcite grains. Twin strain, mean width, and intensity of twinning, and the relative magnitude and orientations of principal stresses were calculated using Calcite Strain Gauge program. Twin strain, mean width, and intensity of twinning showed ranges of 1.09-15.36%, 0.53-3.72 ㎛ and 21.0-53.1 twim/mm, respectively. Metamorphic temperatures calculated from the twins were 170-200℃, indicating that the twins developed after the Pungchon limestone was uplifted to at least half of the maximum burial depth. Results for five of the samples indicate that the calcite twins formed during two events with principal stress axes of different orientations, while the remaining sample recorded only one event that produced calcite twins. The axis of maximum compressive stress was oriented mainly WNW-ESE to ENE-WSW, and to a lesser degree NW-SE and NE-SW. Comparison of paleostress orientations measured here and in other studies indicates that most twins were produced during the Songrim orogeny. However, the Daebo orogeny and the Bulguksa orogeny also produced calcite twins in the Punchon limestone.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.129-138
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• 1990

This study investigated the relationship between the cutflow of rural population and agricultural policy by using time series method. For the analytical tools, decomposition time series methods and regression technique were employed in computing seasonal fluctuation and cyclical fluctuation of population migration. Also, this study predicted farmhouse, rural population till the 2000's by means of the mathematical methods. The analytical forms employed in forecasting farmhouse, rural population were Exponential curve, Gompertz curve and Transcendental form. The major findings of this study were identified as follows: 1) Rural population and farmhouse population began to decrease from 1965 and hastily went down since 1975. Rural population which accounted for 36.4 percent, 35.6 percent of national population respectively in 1960 diminished about two times: 17.5 percent, 17.1 percent respectively. 2) The rapid decreasing of the rural population was caused because of the outflow of rural people to the urban regions. Of course, that was also caused from the natural decreases but the main reason was heavily affected more the former than the latter. In the outflowing course shaped from rural to the urban regions, rural people concentrated on such metropolis as Seoul, Pusan, Keanggi. But these trends were diminishing slowly. On the other hand, compared with that of the 1970's the migration to Keanggi was still increasing in the 1980's. That is, people altered the way of migration from the migration to Seoul, Pusan to the migration to the out-skirts of Seoul. 3) The seasonal fluctuation index of population migration has gone down since the June which the request of agricultural labor force increases and has turned to be greatly wanted in the March as result of decomposition time series method. As result of cyclical analysis, the cyclical patterns of migration have greatly 7 cycle. 4) As result of forecasting the rural and farmhouse population, rural and farmhouse population in the 2000 will be about 9,655(thousand/people) and 4,429(thousand/people) respectively. Thus, it is important to analyze the probloms that rural and farmhouse population will decrease or increase by the degree. But fairly defining the agricultural into a industry that supply the food, this problem - how much our nation need the rural and farmhouse population - is greatly significant too. Therefore, the basic problems of the agricultural including the outflows of rural people are the earning differentials between rural and urban regions. And we should regard the problems of the gap of relative incomes between rural and urban regions as the main task of the agricultural policy and treat the agricultural policy in the viewpoint of developing economic equilibrium than efficiency by using actively the natural resources of the rural regions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.251-264
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• 1992

Distribution of indicator species of copepods and chaetognaths were studied as an indicator species of water mass in the southeastern area of the Yellow Sea. Undinula darwini, Lucicutia flavicornis, Pleuromamma gracilis, Euchaeta resselli, Euchaeta plane and Sagitta enflata were found to be reliable indicator species for determining warm water mass. Of these species, E. plana and E. rusrelli have a weak tolerance on the low temperature. Sagitta crassa was indicator species of neritic waters; Sagitta bedoti was that of mixing waters. Centropages abdominalis represented neritic cold waters. In February, U darwini, L. flavicornis, P. gracilis, E. russelli, E. plana and S. enflata occurred in the western waters of Cheju-Do where warm waters over $14^{\circ}C$ occupied. Centropages abdominalis occurred in the northern area beyond Chindo with water temperature less than $10^{\circ}C$. E. plana, E. russelli and S. bedoti were found at the regions between Cheju-Do and Chindo where the water temperature was $12- 14^{\circ}C$ corresponding to the mixing waters. Based on cluster analysis and T-S diagram in February three different water masses were identified from the south to the north. In August, water masses were analyzed at two different layers, 0-20m and 20m- bottom layers, separated by bhermocline depth. In 0-20m layer, E. plana and E. russelli were found from the western waters of Cheju-Do to Daehuksando. In 20m- bottom layer, E. russelli and E plena occurred at the northwestern waters of Cheju-Do with the water temperature warmer than $12^{\circ}C.\;C.$ abdominalis was found at the northern area beyond Chindo. Based on the cluster analysis and T-S diagram in August three different water masses at 0-20m and 20m-bottom layers were identified from the coast to the offshore. C. abdominalis was found at the adjacent water of Chindo at 0-20m layer and the northern area beyond Chindo at 20m~bottom layer. This fact suggested that the cold water mass existed at tile adjacent waters of Chindo in summer.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.576-587
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• 2015

This paper presents a quantitative evaluation of water permeability in concrete with cold joint considering mineral admixture and loading conditions. Concrete samples with OPC (Ordinary Portland Cement) and GGBFS(Ground Granulated Blast Furnace Slag) are prepared considering 0.6 of W/C ratio and 40% of replacement. 30% and 60% loading levels for compression and 60% loading level for tension are induced to concrete samples. In compression conditions, the permeability in control case shows $2.41{\times}10^{-11}m/s$ in OPC concrete, and it changes to $2.07{\times}10^{-11}m/s$ (30% of peak) and $2.36{\times}10^{-11}m/s$ (60% of peak). The results in GGBFS concrete shows the same trend, which yields $2.17{\times}10^{-11}m/s$ (control), $1.65{\times}10^{-11}m/s$ (30% of peak), and $1.96{\times}10^{-11}m/s$ (60% of peak), respectively. In tensile conditions, the permeability increases from $2.37{\times}10^{-11}m/s$ (control) to $2.67{\times}10^{-11}m/s$ (60% of peak) while that in GGBFS concrete increases from $2.17{\times}10^{-11}m/s$ (control) to $2.24{\times}10^{-11}m/s$ (60% of peak). Permeability coefficients decreases in 30% of compressive level but increases in 60% level, while results in tensile level increases rapidly. This shows pore structure in concrete is condensed and with loading and permeability increases due to micro-cracking. Permeability evaluation considering the effects of loading conditions, cold joint, and GGBFS is verified to be important since water permeability greatly changes due to their effects.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.601-615
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• 2013

This study was conducted to compare the community structure and biodiversity of arthropods between conventional and organic red pepper fields. A total of 36 species of 24 families belonging to 10 orders from collected 28,718 arthropods; 6,901 individuals from conventional field and 21,871 individuals from organic field. A number of species comprising arthropod community was same in both fields as 32 species. Species richness of Diptera was the highest in conventional field and that of Hymenoptera and Colembolla was the highest in organic field. Abundance of Frankliniella intonsa was the highest regardless of farming method. Helicoverpa assulta was dominant in conventional field, and Homidia mediaseta, Diptera sp. 4 and Pardosa astrigera were dominant in organic field. Diversity of community on the ground was higher in organic field and statistically different. Similarity of arthropod community showed difference with 34.07% on the ground and 26.95% in the plant above ground. In the ecologically functional guild: species richness of general, pest and parasitoid of natural enemy groups in the plant above ground were statistically different and pest and parasitoid groups were higher in organic field, abundance of predator group of natural enemy on the ground was 2 times higher in organic field and statistically different and diversity of general and parasitoid groups in the plant above ground were statistically different. In the relative occupancy rate, pest group was the highest in conventional field and decomposer group was the highest in organic field. The results of present study is considered to provide useful information of arthropod community for developing efficient insect pest management in organic farming.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.191-197
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• 2018

This study investigated the influence of starch extraction (ST-EX) solutions on the extraction yield and characteristics of Chinese yam (CY) starches from domestic Dioscorea batatas. Ascorbic acid (VitC), $Na_2S_2O_3$, $NaHCO_3$, and $Na_2CO_3$ were used as ST-EX solutions (0.4%, w/v). The extracted CY starches were examined for ST-EX yield, chemical composition, size distribution, X-ray diffraction, solubility, swelling power, gelatinization, and pasting viscosity. The highest ST-EX yield was obtained from $NaHCO_3$, followed by VitC. Lower protein content, relative crystallinity, and gelatinization enthalpy were found in CY starches from alkaline ST-EX solutions ($NaHCO_3$ and $Na_2CO_3$). Size distribution and gelatinization temperature did not generally differ for CY starches from the different ST-EX solutions. Pasting viscosities increased in the order from $Na_2CO_3$ > $Na_2S_2O_3$ > $NaHCO_3$ > VitC ST-EX solutions. Thus, VitC may be most appropriate to extract CY starch from Dioscorea rhizomes, considering its ST-EX yield, total starch content, and variation in pasting viscosity.

• Journal of Chest Surgery
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• v.29 no.12
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• pp.1329-1336
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• 1996

From January, 1994 to January. 1996, mitral valve replacement was performed in 27 patients. Among these, 17 patients underwent mitral valve replacement(MVR) with preservation of the annulo-papillary continuity(PAPCMVR) (-Group I), and 10 patients underwent conventional methods of excision of all the chordae(Group II). The operative technique for PAPCM VR consists of the division of the anterior leaflet into anterior and posterior segments, shifting and reattachment of the divided segments to the mitral ring of the respective commissural areas. This retrospective study has been designed to evalute the postoperative left ventricular function in the two groups. In the group 1, LVEF(Left Vnetricular Ejection Fraction : %) was 52 $\pm$ 3 preoperatively And 50$\pm$3 postoperatively, LVESI Vent icular End Systolic Volume Index/mL/m2) wIns 59 :6 and 51 $\pm$ 7, LVEDI Ventricular End Diastolic Volume Index/mL/m2) was 124$\pm$ 11 and 91 :8. In the group II, LVEF was 56$\pm$1 and 47:), LVESVI 62$\pm$12 and 61$\pm$15, LVEDVI 133$\pm$27 and 104$\pm$17. : the variation of the LVEF in these two group was statistically different(p(0.05). A comparison of left ventricular function data between Group I(n: 17) and Group II(n: 10) revealed better results in echocardiographic LVEF(p<0.05), LVEDVI(p<0.01) in the former group. The mean functional class(UYHA) was 2.6 preoperative and improved to 1.0 postoperatively In group 1, and 2.8 and to 1.0 in group II. We conclude that maintenance of continuity between the mitral annulus and papillary muscles is expected to have a beneficial effect on postoperative left ventricular performance.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.355-366
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• 2008

The composition and abundance of mesozooplankton were studied from the five stations on the Bulgap stream near Yeonggwang, Jeollanamdo, Korea. Mesozooplankton samples were collected bimonthly in April, July, August, October, and December 2006 and February 2007. Total 44 taxa of mesozooplankton occurred with the highest abundance (31$\sim$53,230 indiv. m$^{-3}$) in October, and the fewest (16$\sim$97 indiv. m$^{-3}$) in December. Diversity index is the highest in July (1.072) and the lowest in October (0.386). The two copepod species, Pseudodiaptomus inopinus and Macrocyclops albidus were dominant during the study periods. A brackishwater species, P. inopinus occurred in the Bulgap stream during from August 2006 to February 2007. This species was the most dominant species (53,010 indiv. m$^{-3}$) in the stations that usually have low salinities (0.1$\sim$14.0 psu). M. albidus was predominated during from April to August 2006 in the freshwater stations.

• Proceedings of the Korean System Dynamics Society
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• 2003.08a
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• pp.83-108
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• 2003

한 산업에서 인력 수급을 전망하는 것은 인력의 수요자인 기업의 측면에서는 안정적인 인력 확보 전략을 수립하기 위해서, 공급자인 산업 종사자들에게 있어서는 자신들이 앞으로 진출해야할 산업의 매력도를 파악하기 위해서, 그리고 정부 차원에서는 관련 산업에 있어서 중복 투자의 방지와 효율적이고 균형 된 산업 발전을 위한 정책 수립을 위해서 매우 중요하다. 그러나 이러한 인력 수급 전망들은 종종 잘못된 시장 분석으로 인하여 인력의 과소 공급 또는 과잉 공급이라는 의도하지 않은 결과를 가져오는 경우가 있다. 이는 전체적인 시각에서 시장의 구조적 특성을 분석하기보다는 현상을 조사하는 수준에 머물거나 현재의 상황 또는 단일 산업만을 고려할 뿐 시간의 흐름에 따른 동태적 변화와 지연된 피드백의 효과, 그리고 관련 산업간의 유기적 연관관계를 반영하지 못한 채 단기적이고 단선적인 관점에서 인력 수급을 전망하는데 그 원인이 있다고 볼 수 있다. 특히, 다른 산업과의 연관 관계가 복잡하고 인력의 수요의 급증에도 불구하고 산업에서 요구하는 인력을 양성하기까지 많은 시간이 소요되는 첨단 산업 및 신생 산업에서의 경우 이러한 현상은 더욱 두드러지게 나타날 수 있다. 이러한 관점에서 본 논문은 변수간의 상호 동태적인 관계와 시간의 흐름에 따른 행태를 분석하는 데 용이한 SD 방법론에 기초하여 최근 빠르게 성장하고 있는 정보보호산업에서의 동태적인 인력 수급 모델을 구현하여 향후 국내 정보 보호 인력의 수급 행태가 어떻게 전개될 것인지를 분석해 보았으며 이를 통하여 동태적 시각에서 인력 수급 불균형 현상의 원인을 파악하고 문제 해결을 위한 대안을 제시하고자 한다.채취하여 임신진단키트(제네디아프로테 트, 녹십자)를 이용하여 임신여부를 1차적으로 확인하였다. 과배란을 유기한 13두의 공란우중 9두(69.2%)가 과배란 반응을 나타내었으며, 회수된 수정란 51개중 이식가능수정란은 38개(74.5%) 였다. 발정동기화를 유도한 수란우 40두중에서 35두(87.5%)가 발정이 동기화되었으며, 그 중 황체검사를 통하여 30두의 수란우에 수정란을 이식하였다. 수정란이식후 13일(발정주기 21일)에 혈액을 이용한 임신진단에서 농가별 수태율은 각각 37.5%, 70.0%, 60.0% 및 71.4% 로서 평균 60.0%를 나타내었다.서 39$^{\circ}C$, 5% $CO_2$ 배양기에 48시간 배양하면서 생존여부를 판단하였다. 실험 2에서 확장배반포배 수정란이 25.3%의 생존율을 나타내었으며, 실험 1과 실험 3에서는 수정란의 형태와 관계없이 생존성을 확인할 수 없었다. 이상의 결과로 보아 glycerol 완만동결에서는 확장배반포기 수정란 이상이 보존가능한 것으로 추정되나 더 추가적인 연구가 요구된다.c kinase 활성의 변동은 정소 내 간충조직, 세정관 상피의 증식 및 기능적 분화 과정을 매개하는 생리적 활성분자 수용체 하위의 신호전달 과정에 Src-Csk loop에 의한 조절가능성을 확인할 수 있었다.rugrene의 향기성분이 주요 성분군으로 확인되었다. 2. 생강나무에서 생강의 향기를 발산하는 성분으로는 $\beta$-myrcene, o-terpinolene, phellandrone, ι-limonene, $\beta$-eudes