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Review of applicability of Turbidity-SS relationship in hyperspectral imaging-based turbid water monitoring (초분광영상 기반 탁수 모니터링에서의 탁도-SS 관계식 적용성 검토)

  • Kim, Jongmin;Kim, Gwang Soo;Kwon, Siyoon;Kim, Young Do
    • Journal of Korea Water Resources Association
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    • v.56 no.12
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    • pp.919-928
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    • 2023
  • Rainfall characteristics in Korea are concentrated during the summer flood season. In particular, when a large amount of turbid water flows into the dam due to the increasing trend of concentrated rainfall due to abnormal rainfall and abnormal weather conditions, prolonged turbid water phenomenon occurs due to the overturning phenomenon. Much research is being conducted on turbid water prediction to solve these problems. To predict turbid water, turbid water data from the upstream inflow is required, but spatial and temporal data resolution is currently insufficient. To improve temporal resolution, the development of the Turbidity-SS conversion equation is necessary, and to improve spatial resolution, multi-item water quality measurement instrument (YSI), Laser In-Situ Scattering and Transmissometry (LISST), and hyperspectral sensors are needed. Sensor-based measurement can improve the spatial resolution of turbid water by measuring line and surface unit data. In addition, in the case of LISST-200X, it is possible to collect data on particle size, etc., so it can be used in the Turbidity-SS conversion equation for fraction (Clay: Silt: Sand). In addition, among recent remote sensing methods, the spatial distribution of turbid water can be presented when using UAVs with higher spatial and temporal resolutions than other payloads and hyperspectral sensors with high spectral and radiometric resolutions. Therefore, in this study, the Turbidity-SS conversion equation was calculated according to the fraction through laboratory analysis using LISST-200X and YSI-EXO, and sensor-based field measurements including UAV (Matrice 600) and hyperspectral sensor (microHSI 410 SHARK) were used. Through this, the spatial distribution of turbidity and suspended sediment concentration, and the turbidity calculated using the Turbidity-SS conversion equation based on the measured suspended sediment concentration, was presented. Through this, we attempted to review the applicability of the Turbidity-SS conversion equation and understand the current status of turbid water occurrence.

A Study on the Success Factors of Co-Founding Start-up by Step: Focusing on the Case of Opportunity-type Start-up (공동창업의 단계별 성공요인에 관한 연구: 기회형 창업기업 사례를 중심으로)

  • Yun, Seong Man;Sung, Chang Soo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.1
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    • pp.141-158
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    • 2023
  • From the perspective of an entrepreneur, one of the most important factors for understanding the inherent limitations of a startup, reducing the risk of failure, and succeeding is the composition of the talent, that is, the founding team. Therefore, a common concern experienced by entrepreneurs in the pre-entrepreneurship stage or the early stage of startup is the choice between independent startups and co-founding start-up. Nonetheless, in Korea, the share of independent entrepreneurship is significantly higher than that of co-founding start-up. On the other hand, focusing on the fact that many successful global innovative companies are in the form of co-founding start-up, the success factors of co-founding start-up were examined. Most of the related preceding studies are studies that identify the capabilities and characteristics of individual entrepreneurs as factors influencing the survival and success of entrepreneurship, and there is a lack of research on partnerships, that is, co-founding start-up, which are common in the field of entrepreneurship ecosystems. Therefore, this study attempted a multi-case study through in-depth interviews, collection of relevant data, analysis of contextual information, and consideration of previous studies targeting co-founders of domestic startups that succeeded in opportunistic startups. Through this, a model for deriving the phased characteristics and key success factors of co-founding start-up was proposed. As a result of the study, the key element of the preliminary start-up stage was 'opportunity', and the success factors were 'opportunity recognition through entrepreneur's experience' and 'idea development'. The key element in the early stages of start-up is "start-up team," and the success factor is "trust and complement of start-up team," and synergy is shown when "diversity and homogeneity of start-up team" are harmonized. In addition, conflicts between co-founders may occur in the early stages of start-ups, which has a large impact on the survival of start-ups. The conflict between the start-up team could be overcome through constant "mutual understanding and respect through communication" and "clear division of work and role sharing." It was confirmed that the core element of the start-up growth stage was 'resources', and 'securing excellent talent' and 'raising external funds' were important factors for success. These results are expected to overcome the limitations of start-up companies, such as limited resources, lack of experience, and risk of failure, in entrepreneurship studies, and prospective entrepreneurs preparing for a start-up in a situation where the form of co-founding start-up is attracting attention as one of the alternatives to increase the success rate. It has implications for various stakeholders in the entrepreneurial ecosystem.

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A Study of the Influence of Start-up New Product Preannouncing Information Attributes on Purchase Intention: Focused on UTAUT2 (프리어나운싱 정보속성이 스타트업 신제품 구매의도에 미치는 영향에 관한 연구: 확장된 통합기술수용이론(UTAUT2)을 중심으로)

  • Byung-chul Han;Jae-Hyun You
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.5
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    • pp.1-16
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    • 2023
  • Due to imbalances in supply and demand within the labor market, start-ups have emerged as crucial players in the generation of high-quality employment opportunities, particularly in stagnant job markets. In response to this trend, governments are allocating substantial financial and human resources to initiatives that support start-up development. This has led to an increasing rate of engagement in start-up ventures across diverse age groups, not limited to younger individuals. Start-ups are enterprises focused on the commercialization of innovative ideas with the aim of achieving profitability in the marketplace. Research concerning the successful market integration of new products and the attainment of sustainable growth is pivotal. Such research is instrumental not only for the success of start-ups but also for realizing the broader social functions and contributions that these enterprises can offer. Previous research has often examined new product market-entry strategies, often referred to as new product marketing, particularly for large companies and SMEs. However, there is a gap in studies focusing on prototype marketing strategies specific to start-ups. Thus, this study aims to examine the impact of Pre-announcing marketing strategies on the market attention garnered by start-ups with low recognition and limited infrastructure, and how such attention contributes to their sustainable growth. Specifically, the study aims to uncover the causal relationship between information attributes like relevance, vividness, and novelty in building customer relationships, and their impact on purchase intentions influenced by performance expectations and hedonic motivations. In terms of Pre-announcing information attributes, relevance, vividness, and novelty positively influence performance expectations and hedonic motivations as outlined in the extended Unified Theory of Acceptance and Use of Technology (UTAUT2). These factors, in turn, positively impact the purchase intention for pre-announced new products from start-ups. These findings are expected to provide both theory and practical insights into the factors influencing market entry through the use of Pre-announcing marketing strategies for start-up new products.

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The Hybrid Organization's Response to Conflicting Institutional Demands: A Case Study about Social Ventures (하이브리드 조직의 모순 대응 전략 변화: 소셜벤처 노을과 에누마 사례를 중심으로)

  • Jin, Wooseok;Seong, Jieun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.5
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    • pp.151-168
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    • 2022
  • Nowadays companies are required to achieve social goals beyond maximizing shareholder profits. Accordingly, it is important to pursue both the economic and social goals of a company at the same time. Thus the importance of hybrid organizations is increasing theoretically and practically. In particular, since hybrid organizations essentially have the complexity of pursuing both economic and social purposes, the institutional demands of various stakeholders surrounding hybrid organizations are also conflicting. Several previous studies have considered how hybrid organizations respond to these conflicting institutional demands, but most studies are limited to studying at a specific point in time. As a result, there was a limit to analyzing the dynamics in response to conflicting institutional demands as the hybrid organization expanded its business. This study predicted that the hybrid organization would take selective coupling with conflicting institutional demands and that the process of responding to institutional demands would change according to the organization's growth. In this study, we had a case study about Noul and Enuma, social ventures that operate relatively advanced business models with outstanding results in innovation and technology. As a result, social ventures show a selective coupling for conflicting institutional demands, and the selective coupling process changes as their business model are advanced. Specifically, in the early stages of the business, it appears to respond to economic and social demands at the same time with a single business model. When the business is advanced, two or more business models are operated, some of which respond to economic needs and some of which respond to social needs. In the early stages of business, social ventures respond to economic and social demands with a single business model to gain legitimacy and survive in the institutional demands. But when they enter the business growth period, they try to separate business models which respond to economic and social values because they pursue sustainable growth and challenge large-scale missions. Overall, this study attempted to contribute to an in-depth understanding of hybrid organizations by identifying that the method of responding to conflicting institutional demands varies depending on the growth process of social ventures.

Suggestions on Expanding Admission Number of Medical School (의과대학 정원 확대에 대한 제언)

  • Eun-Cheol Park
    • Health Policy and Management
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    • v.34 no.2
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    • pp.120-128
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    • 2024
  • From February to now 2024, there continues to be controversy over the expansion of admission number to medical school. Some of the controversy arises from a mix of present and future time points. In the present time point, the controversy over whether physicians are some shortages or not has various aspects. Some aspects are presented as evidence of the physician shortage and others as non-shortage. Also, the presenting evidence of shortage is being disputed, and so is the evidence of the contrary. This controversy over whether there is a shortage or not in the present time point makes it difficult to reach a consensus. In 10 years, the shortage of doctors will increase due to the rapid increase in the elderly population, so the admission number of medical schools will need to be increased. However, the increase must be such that there is minimal deterioration in the quality of medical education. More admission numbers should be allocated to medical schools with a high quality of medical education. This study suggests that large-scale medical schools increase the admission number by 20%-30%, and small-scale medical schools increase the admission number by 40%-50%, if so, the total increasing number is 760 to 1,066. If the 2,000-person increase is enforced, the quality of medical education must be carefully evaluated and the results should be reflected in adjusting the admission number of medical schools. In 20 years later, the admission number of medical schools will have to be reduced. This is because the physician supply is changing to a linear function and the physician demand (medical care demand) is changing to a quadratic function. Even if the current number is maintained, there will be an excess of doctors from 2048, so the medical school admission number must be reduced and its size will be reduced to about 2,000, a 30% reduction from the current number. Because the same reduction rate for all medical schools will result in many small-scale medical schools, the M&A (mergers and acquisitions) strategy should be considered with 40 medical schools and 12 Korean medical schools. In Korea, the main contributor to estimating physician demand is the change in population structure. Due to the rapid decrease in the total fertility rate, future population projections are uncertain. The recent rapid increase in healthcare utilization should be reexamined in the forecasting of physician demand. Since the various factors that affect the estimate of doctor supply and demand are unclear, the estimate of physician supply and demand must be continuously conducted every five years, and the Health Care Workforce Committee must be established and operated. The effects of increasing the admission number of medical schools should be evaluated and adjusted annually.

A Study on the History and Iconological Composition of Jagyeongjeon Hall's Flowered Wall in Gyeongbokgung Palace (경복궁 자경전(慈慶殿) 꽃담의 내력과 도상(圖像) 구성에 관한 재고)

  • OH Junyoung
    • Korean Journal of Heritage: History & Science
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    • v.57 no.2
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    • pp.80-100
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    • 2024
  • This paper investigated the major history and reality of iconological composition for Jagyeongjeon Hall's flowered wall in Gyeongbokgung Palace, which was controversial in terms of preservation and management of cultural heritage. While analyzing the moment and cause of the flowered wall's renovation as it is now, modified or disappeared patterns were identified, and meaningfully misinterpreted congratulatory phrases were reviewed. The research results can be used as meaningful basic data when discussions are made for the restoration of the wall in the future. Jagyeongjeon Hall's flowered wall has reached the present day with large and small changes, but the inflection point that had a significant impact was the Joseon Expo (朝鮮博覽會) held at Gyeongbokgung Palace in 1929. This is because the wall that remained in the Jagyeongjeon Hall area was demolished to build an exhibition hall while preparing for the expo, and it was restored after the end of the event. It is highly likely that the modification or disappearance of the patterns constituting Jagyeongjeon Hall's flowered wall was also due to the restoration process carried out after the expo. There is a view that was transformed into its current state in the process of repair work carried out after the Korean War, but it is difficult to find any meaningful circumstances and evidence. Currently, character patterns known as 'Seongnidori(聖人道理)' are arranged on the inner wall of the section from Gyeongdomun Gate(擎桃門) to Yeogangmun Gate(如岡門), but considering the design form and example, it can be read as 'Seongjasinson(聖子神孫)'. The inner wall of the section from Yeogangmun Gate to Yeonsumun Gate(燕壽門) was originally made in the form of a flowered wall, and the phrases presumed to be 'Gyegyeseungseung(繼繼繩繩)' and 'Cheonse(千世)' were arranged. In the case of the section from Yeonsumun Gate to Hamgyumun Gate(含奎門), the inner wall where the pattern has disappeared is originally composed of geometric and character patterns, and there were also phrases specified as 'Cheonsu(千壽)' and 'Mansemansu(萬世萬壽)'. On the outer wall of the section from Yeonsumun Gate to Hamgyumun Gate, there is a possibility that the phrase known as 'Nakgangmanse(樂彊萬歲)' can be read as 'Cheonsemanse(千歲萬歲)'. In addition, the current outer wall was composed of one drawing board, but in the past, two drawing boards were composed separately.

Estimate of Particulate Organic Carbon Export Flux Using $^{234}Th/^{238}U$ Disequilibrium in the Southwestern East Sea During Summer (동해 서남해역에서 여름철 $^{234}Th/^{238}U$ 비평형을 이용한 입자상 유기탄소 침강플럭스 추정)

  • Kim, Dong-Seon;Choi, Man-Sik;Oh, Hae-Young;Kim, Kyung Hee;Noh, Jae-Hoon
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.14 no.1
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    • pp.1-9
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    • 2009
  • Export fluxes of particulate organic carbon were estimated for the first time by using $^{234}Th/^{238}U$ disequilibrium in the southwestern East Sea during August 2007. They were calculated by multiplying POC/$^{234}Th_p$ ratios of sinking particles (larger than 0.7 ${\mu}m$) obtained from 150-200 m water depths to $^{234}Th$ fluxes that were estimated by integrating $^{234}Th/^{238}U$ disequilibrium from surface to 100 m water depth. Export fluxes ranged from 14 to 505 mg C $m^{-2}$ $day^{-1}$, with the highest value at station A2 and the lowest value at station D4. Primary production was well correlated with export flux, indicating that it was a major factor controlling export flux. Export flux in the East Sea was generally higher than those estimated in the open ocean and similar to or somewhat higher than those in the continental marginal seas. Export flux/primary production (EF/PP) ratios varied from 0.29 to 0.62, with an average of 0.43 and were somewhat higher in the basin area than in the coastal area. EF/PP ratio in the East Sea was rather similar to those estimated in the North Sea and Chukchi Sea, but much higher than those in the Labrador Sea, Barents Sea, and Gulf of Lions. Therefore, the East Sea is one of the major areas where a large amount of organic carbon produced in the euphotic zone sinks into the deep layer below 200 m water depth.

Seasonal Variation in Species Composition of Estuarine Fauna Collected by a Stow Net in the Han River Estuary on the mid-western coast of Korea (한강 하구역 유영생물의 종조성과 계절 변동)

  • Hwang, Sun-Do;Rhow, Jin-Goo
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.15 no.2
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    • pp.72-85
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    • 2010
  • Seasonal variation in species composition of estuarine fauna in the Han River estuary was determined using monthly samples collected near Ganghwa Island by a bag net from February to December 2009. Total number of species was 86: 54 species of fishes, 16 species of shrimps of crustacean, 12 species of other crustacean such as craps and so on, 3 species of cephalopods and 1 species of jellyfish. Of a total of 86 species, Palaeman carinicauda (32.6%), Acetes japonicus (15.9%), Palaemon gravieri (9.9%), Portunus trituberculatus (7.7%) and Acetes chinensis (6.9%) were predominated in abundance. These 5 crustacean accounted for 73% of total. Abundance, biomass and diversity of Han River estuarine fauna were high in spring and autumn, indicating typical pattern of temperate area. Out of dominant species, the brackish residence species such as Coilia nasus, Chelon haematocheilus, Mugil cephalus, Synechogobius hasta, Lophiogobius ocellicauda, Tridentiger barbatus, Palaeman carinicauda, Palaemon gravieri were collected almost year-round and predominated in abundance. Coastal migratory fauna species such as Coilia mystus, Thryssa hamiltonii, Thryssa adelae, Sardinella zunasi, Engraulis japonicus, Portunus trituberculatus, Acetes japonicus, Collichthys lucidus, Pampus argenteus were most plentiful from spring through autumn. Their adult coastal migratory entered the estuary in spring and large numbers of their juveniles were grew in summer and autumn until moving out to deeper waters for over-wintering, indicating they use estuary as nursing ground. Diadromous fish such as Anguila japonica adults were collected in autumn during their downstream migration. Brackish fauna and crustacean, especially shrimps were predominant, and few contaminant indicator species collected in the Han River estuary, indicating this area maintains the characteristics of natural estuary ecosystem.

Improvement of Oxygen Isotope Analysis in Seawater samples with Stable Isotope Mass Spectrometer (질량분석기를 이용한 해수 중 산소안정동위원소 분석법의 개선)

  • Park, Mi-Kyung;Kang, Dong-Jin;Kim, Kyung-Ryul
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.13 no.4
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    • pp.348-353
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    • 2008
  • Oxygen isotope has not been used actively in water mass studies because of difficulties on the analysis though it has advantages as a water mass tracer. The most popular method to analysis the oxygen isotope ratio in water samples is equilibration method: isotopic equilibrium of water with $CO_2$ at constant temperature. The precision of oxygen isotope analysis using commercial automatic $H_2O/CO_2$ equilibrator is ${\pm}0.1%o$. This value is not sufficient for studies in open ocean. The object of this study is to improve the analytical precision enough to apply open ocean studies by modification of the instrument. When sample gas is transferred by the pressure difference, the fractionation which is preferential transportation of light isotope can be occurred since the long transportation path between the equilibrator and mass spectrometer. And the The biggest source of error during the analysis is long distance and large volume of the pathway of sample gas between. Therefore, liquid nitrogen trap and high vacuum system are introduced to the system. The precisions of 14 time analysis of same seawater sample are ${\pm}0.081%o$ and ${\pm}0.021%o$ by built-in system and by modified system in this study, respectively.

Distribution Patterns of Carbon and Nitrogen Contents in the Sediments of the Northeast Equatorial Pacific Ocean (북동 적도태평양해역 퇴적물의 탄소 및 질소함량 분포특성)

  • Kim, Kyeong-Hong;Hyun, Jung-Ho;Son, Ju-Won;Son, Seung-Jyu
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.13 no.3
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    • pp.210-221
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    • 2008
  • The mesoscale environmental surveys were conducted between $5^{\circ}N\;and\;17^{\circ}N$ mainly along the $131.5^{\circ}W$ meridian from 1997 to 2002 to investigate controlling factors of carbon and nitrogen contents in bottom sediments. Sediments of the study area showed zonal distribution pattern depending on latitudinal position and can be classified into four types; calcareous ooze($5{\sim}6^{\circ}N$), siliceous sediments($8{\sim}12^{\circ}N$), pelagic red clay($16{\sim}17^{\circ}N$), and mixed sediments($7^{\circ}N$). Inorganic carbon(IC) contents varied depending on water depth and carbonate compensation depth(CCD). Carbonate materials were well preserved in the low latitude region, where water depths are shallower than CCD. In contrast, the higher latitude region dominated by siliceous sediment and pelagic red clays has low productivity in water column as well as the water depths deeper than CCD. Thus, most of carbonate materials were dissolved, which resulted in IC contents of less than 0.05% in the sediments. Organic carbon(OC) and total nitrogen contents(TN) in siliceous sediments were higher than in pelagic red clay sediments simply because of higher primary productivity in the siliceous sediment dominated area. The contents of OC and TN were lower in the calcareous ooze than in the siliceous sediments. It is attributed to the high input of calcareous material to the bottom due to relatively shallow water depth of the area, which diluted organic matter contents in the sediment. Overall results indicated that water depth relative to CCD, primary production in water column, and sedimentation rate largely controls the large-scale distribution of carbon and nitrogen contents in the study area.