• Title/Summary/Keyword: Drop Value

Search Result 529, Processing Time 0.022 seconds

Estimating the Investment Value of Fuel Cell Power Plant Under Dual Price Uncertainties Based on Real Options Methodology (이중 가격 불확실성하에서 실물옵션 모형기반 연료전지 발전소 경제적 가치 분석)

  • Sunho Kim;Wooyoung Jeon
    • Environmental and Resource Economics Review
    • /
    • v.31 no.4
    • /
    • pp.645-668
    • /
    • 2022
  • Hydrogen energy is emerging as an important means of carbon neutrality in the various sectors including power, transportation, storage, and industrial processes. Fuel cell power plants are the fastest spreading in the hydrogen ecosystem and are one of the key power sources among means of implementing carbon neutrality in 2050. However, high volatility in system marginal price (SMP) and renewable energy certificate (REC) prices, which affect the profits of fuel cell power plants, delay the investment timing and deployment. This study applied the real option methodology to analyze how the dual uncertainties in both SMP and REC prices affect the investment trigger price level in the irreversible investment decision of fuel cell power plants. The analysis is summarized into the following three. First, under the current Renewable Portfolio Standard (RPS), dual price uncertainties passed on to plant owners has significantly increased the investment trigger price relative to one under the deterministic price case. Second, reducing the volatility of REC price by half of the current level caused a significant drop in investment trigger prices and its investment trigger price is similar to one caused by offering one additional REC multiplier. Third, investment trigger price based on gray hydrogen and green hydrogen were analyzed along with the existing byproduct hydrogen-based fuel cells, and in the case of gray hydrogen, economic feasibility were narrowed significantly with green hydrogen when carbon costs were applied. The results of this study suggest that the current RPS system works as an obstacle to the deployment of fuel cell power plants, and policy that provides more stable revenue to plants is needed to build a more cost-effective and stable hydrogen ecosystem.

Automation of Regression Analysis for Predicting Flatfish Production (광어 생산량 예측을 위한 회귀분석 자동화 시스템 구축)

  • Ahn, Jinhyun;Kang, Jungwoon;Kim, Mincheol;Park, So-Young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2021.10a
    • /
    • pp.128-130
    • /
    • 2021
  • This study aims to implement a Regression Analysis system for predicting the appropriate production of flatfish. Due to Korea's signing of FTAs with countries around the world and accelerating market opening, Korean flatfish farming businesses are experiencing many difficulties due to the specificity and uncertainty of the environment. In addition, there is a need for a solution to problems such as sluggish consumption and price drop due to the recent surge in imported seafood such as salmon and yellowtail and changes in people's dietary habits. in this study, Using the python module, xlwings, it was used to obtain for the production amount of flatfish and to predict the amount of flatfish to be produced later. was used to predict the amount of flatfish to be produced in the future. Therefore, based on the analysis results of this prediction of flatfish production, the flatfish aquaculture industry will be able to come up with a plan to achieve an appropriate production volume and control supply and demand, which will reduce unnecessary economic loss and promote new value creation based on data. In addition, through the data approach attempted in this study, various analysis techniques such as artificial neural networks and multiple regression analysis can be used in future research in various fields, which will become the foundation of basic data that can effectively analyze and utilize big data in various industries.

  • PDF

Influence of Water-Cement Ratios and Curing Conditions on the Diffusion Characteristics of Chloride Ion in Concrete (콘크리트의 염소이온 확산특성에 미치는 물-시멘트비 및 양생조건의 영향)

  • Bae, Su-Ho;Lee, Kwang-Myong;Kim, Jee-Sang;Jung, Sang-Hwa
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.4A
    • /
    • pp.753-759
    • /
    • 2006
  • To predict service life of concrete structures exposed to chloride attack, surface chloride concentration, diffusion coefficient of chloride ion, and chloride corrosion threshold value in concrete, are used as important factors. Of these, as the diffusion coefficient of chloride ion for concrete is strongly influenced by concrete quality and environmental conditions of structures and may significantly change the service life of structures, it is considered as the most important factor for service life prediction. The qualitative factors affecting the penetration and diffusion of chloride ion into concrete are water-cement (W/C) ratio, age, curing conditions, chloride ion concentration of given environment, wet and dry conditions, etc. In this paper the influence of W/C ratio and curing conditions on the diffusion characteristics of chloride ion in concrete was investigated through the chloride ion diffusion test. In the test, the voltages passing through the diffusion cell were measured by accelerated test method using potential difference, and then with the consideration of IR drop ratio the diffusion coefficient of chloride ion for concrete with different W/C ratios were estimated by Andrade's model. Furthermore, under different curing conditions formulas for the estimation of the diffusion coefficient of chloride ion have been proposed by the regression analysis considering the effect of W/C ratio and age.

Analysis on Wettability of Soil Composed of Sand and Fine-Grained Soil with Hydrophobic Surface (모래와 세립토로 구성된 소수성 흙의 습윤성 분석)

  • Jeong-Jun Park;Kicheol Lee;Seung-Kyong You;Jung-Mann Yun;Gigwon Hong
    • Journal of the Korean Geosynthetics Society
    • /
    • v.22 no.4
    • /
    • pp.43-49
    • /
    • 2023
  • This study described the test results to evaluate the effect of fines content on the wettability of sandy soil composed of hydrophobic soil particles. Wettability was evaluated using the contact angle obtained from the water drop test results for Jumunjin standard sand and sandy soil containing fines content. The test results showed that the wettability of sandy soil composed of sand and fine-grained soil changed depending on the hydrophobic level and fines content. The influence of fines content on the wettability of sandy soil was analyzed. It was found that 1% and 3% hydrophobic sandy soil with 5% fines content decreased by 94.4% and 32.4%, respectively, compared to the contact angle of standard sand. In addition, the contact angle reduction ratio for sandy soil with a 5% hydrophobic level and a fines content of 5% and 10% were 24.4% and 37.3%, respectively. In other words, the wettability of the soils should be evaluated considering the fines content to predict the behavior of contaminants, because the fines content has a significant impact on the value and increase/decrease ratio of the contact angle of sandy soil

Identification of unit hydrograph peak behavior according to changes in precipitation scale in a virtual watershed (가상 유역의 강수 규모 변화에 따른 단위유량도 첨두치의 거동 규명)

  • Yoo, Ju-Hwan;Kim, Joo-Cheol
    • Journal of Korea Water Resources Association
    • /
    • v.56 no.10
    • /
    • pp.655-665
    • /
    • 2023
  • In this study, unit hydrographs are calculated when precipitations of 10 scales instantaneously occurs in a virtual watershed with a constant slope and roughness. Then, the relationship between the peak flow rate and the peak occurrence time of the unit hydrograph was calculated for the precipitation scale, respectively. At this time, the virtual watershed simplified with a rhombic shape, a constant slope, and a flow condition with a certain roughness was applied instead of a natural watershed in order to understand the effect the precipitation scale has on the peak value of the unit hydrograph. And it was assumed that the precipitation in the basin was effective rainfall and the runoff was direct runoff, and the runoff flowed in a straight, uniform flow from the drop point to the outlet. The relationship between the peak flow and the peak occurrence time of the unit hydrograph was calculated in the case of 10 types of precipitation scales of 10 mm, 40 mm, 90 mm, 160 mm, 250 mm, 360 mm, 640 mm, 1,000 mm, 1,210 mm, and 1,690 mm of effective precipitation. A noteworthy achievement of this study is that, even without the storage effect of the watershed, as the scale of precipitation increases, the depth of runoff increases, so the flow rate in the watershed increases and the distance per unit time increases, so the peak flow rate increases and the peak occurrence time increases. This is a nonlinear characteristic of watershed runoff.

Comparison of brain wave values in emotional analysis using video (영상을 이용한 감정분석에서의 뇌파 수치 비교)

  • Jae-Hyun Jo;Sang-Sik Lee;Jee-Hun Jang;Jin-Hyoung Jeong
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.16 no.6
    • /
    • pp.519-525
    • /
    • 2023
  • The human brain constantly emits electrical impulses, which is called brain waves, and brain waves can be defined as the electrical activity of the brain generated by the flow of ions generated by the biochemical interaction of brain cells. There is a study that emotion is one of the factors that can cause stress. Brain waves are the most used in the study of emotions. This paper is a study on whether emotions affect stress, and showed two images of fear and joy to four experimenters and divided them into three stages before, during, and after watching. As a measurement tool, brain waves at the positions of Fp1 and Fp2 were measured using the NeuroBrain System, a system that can automate brain wave measurement, analysis, brain wave reinforcement, and suppression training with remote control. After obtaining the brain wave data for each emotion, the average value was calculated and the study was conducted. As for the frequency related to stress, the values of Alpha and SMR, Low Beta, and High Beta were analyzed. Brainwave analysis affects stress depending on the emotional state, and "fear" emotions cause anxiety by raising Beta levels, resulting in higher Mind Stress levels, while "joy" emotions lower Beta levels, resulting in a significant drop in Mind Stress.

Effect of Shading on Japanese Apricot Fruit Yield and Quality (차광이 매실의 수량 및 품질에 미치는 영향)

  • Jung Gun Cho;Sung Ku Kang;Seung Heui Kim;Sang Kun Park;Yong Bum Kwack
    • Journal of Practical Agriculture & Fisheries Research
    • /
    • v.25 no.4
    • /
    • pp.84-89
    • /
    • 2024
  • Light is an important component among which plays a crucial role in determining the production and quality of fruit trees. Since the disturbance of light directly leads to reduced photosynthetic efficiency, their damage can be increased especially in fruit trees such as Japanese apricots with a short growing time. In this study, we investigated how the effects of shading condition can affect the production and quality of Japanese apricots according to increased damages by light disturbance in the main orchard complex. The average photosynthetically active radiation (PAR) level in Japanese apricots was rapidly dropped as the shading time was increased compared to the control (304 μmol/m2/s) and the PAR level decreased to 142 μmol/m2/s after shaded for eight hours. The maximum photosynthetic efficiency, with a PAR value of 900 to 1,000 μmol/m2/s, corresponds to the time period without shading and the time period with 2 hours of shading, and these times range from 11 a.m. to 3 p.m. And the time period for shading for 4 hours was from 1:00 p.m. to 2:00 p.m., and under conditions of shading for 6 and 8 hours, the effect was a low amount of light. There was no difference in the weight of Japanese apricots during 2 hours shading time, however, it was significantly reduced as shading time were increased. The difference of the acid content and L/D ratio was not significant on shading time, but the SSC was decreased as times going on. In conclusion, our results indicate that the shading for more than 2 hours make negative effects to decrease the weight and SSC and the yield and affects directly to drop in fruit quality.

The Biochemical Studies on Stored Soy-sauce (저장(貯藏)간장의 생화학적(生化學的) 연구(硏究))

  • Chang, Chi-Hyun
    • Applied Biological Chemistry
    • /
    • v.9
    • /
    • pp.9-27
    • /
    • 1968
  • Studies were carried out in order to elucidate chemical components and microflora in three types of soy-sauce, 12-year aged soy-sauce prepared by improved method. 7-year aged and 20-year aged soy-sauce prepared by ordinary method. They results are summarized as follows: 1. The followings are found to be the important factors affecting the quality of soy sauce. a. Organic acids, reducing sugars and free amino acids were increased in the course of storage. b. In the aged soy-sauces under study non-volatile organic acid increased while volatile organic acid decreased and the total acidity was dependent only upon tie latter. c. It was found that suit concentration decreased during the storage. 2. The results of investigation of microflora in the stored soy-sauce are shown as follows. Soy-sauce Improved Ordinary Microbe 12-Y. 20-Y. 7-Y. Aerobic bacteria colony/1ml. 6 123 2 Halophilic lactic acid bacteria colony/1ml. 4 6 10 Osmophilic yeast colony/1ml. 828×104 248 - b. In the stored soy-sauces, aerobic bacteria are incapable of growing due to drop in pH value and the influence of salt concentration. c. Halophilic lactic acid bacteria are incapable of growing due to drop in pH value, even the salt concentrations decreased during the storage. d. Osmophilic yeast are still growing in low pH value and in the decreasing salt concentration during the strage. 3. The results of amino acid analysis by paper partition chromatographic and calorimetric methods are shown as follows. a. Fourteen kinds of amino acid and thirteen amino acids were detected in the soy-sauce of 12-year aged improved soy-sauce and 7-year aged and 20-year aged ordinary one, respectively. b. The contents of aspartic acid, glutamic acid, serine, valine, leucine, lysine, histidine and methionine increased in the 20-year aged ordinary soy-sauce compared to the 7-year aged one. On the other hand those of alanine, tyrosine, phenylalanine and cystine decreased. 4. The results of sugar analysis by paper chromatography are as follows. a. In the 12-year aged improved soy-sauce, galactose, glucose, arabinose, xylose, rhamnose, maltose and an unknown were detected, and their amounts were in the above order except maltose and an unknown. b. Both in the 7 and 12-year aged ordinary soy-sauces, galactose, arabinose, xylose, glucose and rhamnose were detected and the amounts of the sugars were in the above order. c. In the non-aged ordinary soy-sauce, glucose was not detected but detected from 7-year and 20-year aged ordinary soy-sauce. 5. The results of organic acid analysis by paper chromatography were as follows. a. As volatile acids, acetic, propionic and butyric acids were detected in the 7-year aged ordinary soy-sauce. On the other hand in both the 20-year aged ordinary soy-sauce and the 12-year aged improved ones, only acetic acid was abundant while propionic and butyric acids were round in trace. It was found that propionic and butyric acids, as the unpleasant flavor components, decreased during the storage. b. In the ordinary soy-sauce, citric acid were produced during the storage and lack, malic and tartaric acids increased in the course of aging while succinic, glycolic, fumaric and malonic acids were shown to decrease. Glutaric and oxalic acids disappeared. Citric acid was produced also in the improved soy-sauce, but lactic, tartaric, succinic, malic, and glycolic acids decreased, while both malonic and glutaric acids disappeared. From the above results the citric acid production was considered to be a favorable factor for the taste. c. In the aged soy-sauces, pyruvic, α-ketoglutaric and probably acetoacetic and oxaloacetic acids (both in trace) were present and their amounts were in the above order. All of the α-keto acid abruptly decreased during the storage.

  • PDF

Effect of Flooding and Organic Matter to the Release of Iron, Manganese, and Silica in Soils (침수처리(湛水處理) 및 유기물(有機物) 첨가(添加)가 답토양(畓土壤)의 Fe, Mn 및 SiO2의 용출량(溶出量)에 미치는 영향(影響)에 관(關)한 연구(硏究))

  • Park, Y.S.;Oh, W.K.;Park, N.J.
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.1 no.1
    • /
    • pp.1-5
    • /
    • 1968
  • A low yielding paddy soil was water logged at 30±2C with soluble starch as a easily decomposable organic matter for 3 weeks in the laboratory. The relation of pH and Eh changes and soluble iron, manganese and silica was investigated. The experimental results obtained were summarized as follows; 1. When organic matter was applied, reduction of the soil was severer, that is, Eh value was lower by 200 mv. for a week in the beginning of submergence. 2. pH of the untreated soil was dropped a little just after submergence, and then gradually increased to 60. When treated, pH was increased due to abrupt drop of Eh in the beginning but decreased to 4.5 after a week, and became constant at this pH value. 3. Slight increase in soluble iron, manganese and silica was observed in the untreated soil whereas soluble iron, manganese and silica in the treated soil were increased about 20, 10, and 3 times, respectively. 4. When soluble starch was treated, pH and soluble silica or manganese was highly correlated[(H+) and Mn γ=0.734, (H+) and SiO2 γ=0.923] and below pH 5.0, release of these element was rapidly increased.

  • PDF

Changes in Quality of Citron Juice by Storage and Extraction Conditions (유자과즙의 저장 및 착즙조건에 따른 품질변화)

  • Park, Kee-Jai;Jung, Sung-Won;Kim, Jong-Hoon;Jeong, Jin-Woong
    • Applied Biological Chemistry
    • /
    • v.38 no.2
    • /
    • pp.141-146
    • /
    • 1995
  • Changes of physicochemical properties of citron juice prepared by two different extraction methods, rotary-crushing and belt-pressing method, were investigated during the storage at 5C and 20C. Temperature drop of citron juice extracted by belt-pressing method was faster than that of citron juice prepared by rotary-crushing method and its freezing point was 0.80.9C. During the storage, pH of stored citron juice with rotary-crushing method was increased up to 3.5 after 6 months storage while that of citron juice extracted by belt-pressing method was not changed significantly during the same storage time. Acidity of rotary-crushed citron juice was reduced a little more than that of belt-pressed citron juice during the storage. However, changes of soluble solid content were influenced largely by the storage temperature than by the extraction method. Contents of formol nitrogen and vitamin C were reduced remarkably in all of stored citron juice and 9282 of farmol nitrogen and 7243 of vitamin C were remained after 6 months of storage. Among the changes of color value, L values were reduced in the whole stored citron juice and a and b value had a different change pattern respectively according to the extraction and storage temperature. Changes in the content of both amino acid and fatty acid compositions was also observed after same storage period. Especially, in the case of change of fatty acid composition, content of linoleic acid and linolenic acid were reduced after 6 months storage, while those of palmitic acid, stearic acid and oleic acid were increased.

  • PDF