• Journal of Korea Port Economic Association
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• v.38 no.4
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• pp.87-106
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• 2022

Uncertainties in the energy market are increasing due to technology developments (shale revolution), trade wars, COVID-19, and the Russia-Ukraine war. Especially, since 2020, the risk of international trade in the energy market has increased significantly due to changes in the supply chain of transportation and due to prolonged demand reduction because of COVID-19 and the Russian-Ukraine war. Considering these points, this study analyzed connectedness between energy price, tanker index, and uncertainty to understand the connectedness between international trade in the energy market. Main results are summarized as follows. First, as a result of analyzing stable period and unstable period of the energy price model using the MS-VAR model, it was confirmed that both the crude oil market model and the natural gas market model had a higher probability of maintaining stable period than unstable period, increasing volatility by specific events. Second, looking at the results of the analysis of the connectedness between stable period and unstable period of the energy market, it was confirmed that in the case of total connectedness, connectedness between variables was increased in the unstable period compared to the stable period. In the case of the energy market stable period, considering the degree of connectedness, it was confirmed that the effect of the tanker freight index, which represents the demand-side factor, was significant. Third, unstable period of the natural gas market model increases rapidly compared to the crude oil market model, indicating that the volatility spillover effect of the natural gas market is greater when uncertainties affecting energy prices increase compared to the crude oil market.

• Smart Media Journal
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• v.11 no.7
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• pp.76-84
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• 2022

In Korea, where rice is the staple food, there are many cases in which the nutritional composition of food is different at the same weight, even though the same ingredients are used and the food or food name is the same. The cause is closely related to the moisture content of the food according to the cooking method and cooking process. In order to design a diet tailored to individual health and supply accurate calories and nutrients, a method of expressing food data that is not affected by the cooking process or cooking method is required. Usually, the same ingredients or foods show a lot of deviation from the nutritional components presented in the standard food database due to the difference in moisture content. For this reason, there are problems that increase the complexity of the food ingredient database and the difficulty in using it. As a method to improve these problems, we would like to propose a food data expression method based on dry weight. As an example of this, the characteristics of rice as a food material and changes in major nutritional components according to the change in moisture of various rice-processed foods made from rice were considered. In addition, as an example of how to normalize food data through this, the dry weight-based nutrition label of rice was presented.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.517-522
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• 2023

A chemical/mechanical durability test of polymer membrane evaluation method is used in which air and hydrogen are supplied to the proton exchange membrane fuel cell (PEMFC) and wet/dry is repeated in the open circuit voltage (OCV) state. In this protocol, when wet/dry is repeated, voltage increase/decrease is repeated, resulting in electrode degradation. When the membrane durability is excellent, the number of voltage changes increases and the evaluation is terminated due to electrode degradation, which may cause a problem that the original purpose of membrane durability evaluation cannot be performed. In this study, the same protocol as the department of energy (DOE) was used, but oxygen was used instead of air as the cathode gas, and the wet/dry time and flow rate were also increased to increase the chemical/mechanical degradation rate of the membrane, thereby shortening the durability evaluation time of the membrane to improve these problems. The durability test of the Nafion 211 membrane electrode assembly (MEA) was completed after 2,300 cycles by increasing the acceleration by 2.6 times using oxygen instead of air. This protocol also accelerated degradation of the membrane and accelerated degradation of the electrode catalyst, which also had the advantage of simultaneously evaluating the durability of the membrane and the electrode.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.42-42
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• 2020

오이(Cucumis sativa L.)는 1년생 초본의 덩굴성 박과 작물로 미숙한 과실을 다양한 식품 용도로 이용하고 있다. 오이는 시설재배기술 확립으로 연중 생산과 공급이 가능하나 내병성 품종개발이 필요한 실정이다. 또한 오이의 다양한 생리활성 물질에 대한 관심이 높아지고 있어 이를 위한 다양한 오이 자원이 필요한 실정이다. 본 연구에서는 국내외에서 수집한 오이 180자원의 형태적 특성을 분석하여 육종 소재로 활용하는데 있어 기초 정보를 제공하고자 하였다. 본 연구에서 사용된 오이 자원의 원산지는 조지아 98자원, 한국 37자원, 중국 28자원, 우즈베키스탄 17자원이었다. 오이 180자원은 모두 덩굴손을 가졌으며 자웅동주로 조사되었다. 착과습성은 주지형 83자원, 주지 및 측지형 97자원으로 조사되었고 절화당 자화수는 175자원이 2개로 조사되었으며 5자원은 1개로 조사되었다. 과형은 장원형 87자원, 단원형 92자원으로 대부분을 차지하였으며 과선단좁은형이 1자원 조사되었다. 과기부형태는 평평한 형태 83자원, 휘어진 형태 94자원으로 대부분이었으며 오목한 형태 1자원, 뽀족한 형태 2자원이 조사되었다. 과선단의 형태는 평평한 형태 148자원, 휘어지 형태 32자원으로 조사되었다. 오이 유전자원의 개화기는 60~80일로 평균 66.1일 이었으며 과실 성숙기는 33~68일로 평균 49.6일이었다. 국가별로 개화기는 62.4일(중국)~68.5일(한국), 과실성숙기는 48.3일(중국,조지아)~54.1일(우즈베키스탄)로 조사되었다. 본 실험에서 조사된 오이 유전자원의 형태적 특성은 오이 선발에 있어 기초 정보로 활용 가능할 것이며 추가적으로 농업형질, 내병성, 기능성 분석등의 오이 육종 프로그램을 위한 다양한 자원 평가 및 선발이 필요할 것이다.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.55-66
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• 2024

This research addresses the types and causes of defects in seismic retrofitting projects of school facilities, which, following the Gyeongju and Pohang earthquakes in September 2016 and November 2017 respectively, have been identified as having comparatively lower seismic resilience among public buildings. The incidence of seismic retrofitting has notably increased in the subsequent years, raising concerns about the potential for defects arising from these efforts. The government has committed to enhancing the seismic resilience of all public facilities by 2035, with a specific focus on completing upgrades for educational establishments by 2029. Although prior investigations have explored construction defects in school facilities, there exists a gap in research specifically targeting defects within seismic retrofitting processes. Thus, this study aims to catalog the defects associated with seismic retrofitting efforts and analyze their underlying causes to identify crucial management strategies for defect mitigation. Furthermore, by examining the interplay between defect types and their causative factors, the study seeks to pinpoint essential management practices that could preempt defects during the construction phase, ultimately aiding in the reduction of future maintenance expenditures.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.497-510
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• 2022

Agricultural reservoirs are essential structures for water supplies during dry period in the Korean peninsula, where water resources are temporally unequally distributed. For efficient water management, systematic and effective monitoring of medium-small reservoirs is required. Synthetic Aperture Radar (SAR) provides a way for continuous monitoring of those, with its capability of all-weather observation. This study aims to evaluate the applicability of SAR in monitoring medium-small reservoirs using Sentinel-1 (10 m resolution) and Capella X-SAR (1 m resolution), at Chari (CR), Galjeon (GJ), Dwitgol (DG) reservoirs located in Ulsan, Korea. Water detected results applying Z fuzzy function-based threshold (Z-thresh) and Chan-vese (CV), an object detection-based segmentation algorithm, are quantitatively evaluated using UAV-detected water boundary (UWB). Accuracy metrics from Z-thresh were 0.87, 0.89, 0.77 (at CR, GJ, DG, respectively) using Sentinel-1 and 0.78, 0.72, 0.81 using Capella, and improvements were observed when CV was applied (Sentinel-1: 0.94, 0.89, 0.84, Capella: 0.92, 0.89, 0.93). Boundaries of the waterbody detected from Capella agreed relatively well with UWB; however, false- and un-detections occurred from speckle noises, due to its high resolution. When masked with optical sensor-based supplementary images, improvements up to 13% were observed. More effective water resource management is expected to be possible with continuous monitoring of available water quantity, when more accurate and precise SAR-based water detection technique is developed.

• Journal of Dairy Science and Biotechnology
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• v.16 no.2
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• pp.119-136
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• 1998

The lipids of milk provide energy and many essential nutrients for the newborn animal. They also have distinctive physical properties that affect the processing of dairy products. Milk fat globules mainly consist of neutral lipids like triacylglycerols, whereas the globule membranes contain the complex lipids mostly, Phospholipids are a small but important fraction of the milk lipids and are found mainly in the milk fat globule membrane and other membranous material in the skim-milk phase. The milk fats of ruminant animals are characterized by the presence of relatively high concentrations of short-chain fatty acids, especially butyric and hexanoic acids, which are rarely found in milks of non-ruminants. The fatty acids of milk lipids arise from de novo synthesis in the mammary gland and uptake from the circulating blood. The fatty acid compositions of milks are usually complex and distinctive, depending on the nature of the fatty acids synthesized de novo in the mammary gland and those received from the diet in each species. The content and composition of milks from different species vary widely; presumably, these are evolutionary adaptations to differing environments. The actual process by which these globules are formed is unkonwn, but there are indications that triglyceride-containing vesicles which bleb from endoplasmic reticulum may serve as nucleation sites for globules. Recent studies on milk have centred on the manipulation of milk lipids to increase specific fatty acids, i.e. 20-carbon omega-3 fatty acids (eicosapentaenoic acid 20:5n3, decosahexaenoic acid 22:6n3) from marine sources because the fatty acids are closely associated with a decreased risk of coronary heart disease.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.210-218
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• 1991

This study was carried out to investigate the influence of inoculation with Bradyrhizobia and lime types on the nutrient content and yield of peanut. Inoculation size of Bradyrhizobium sp. HCR-46 was $8.2{\times}10^7$ cells per seed. Slaked lime, magnesium lime, and calcium carbonate were applied in an amount required for neutralization of soil. 150kg of calcium sulfate was fertilized to 10a of the experimental field. Sowing space was $40{\times}25cm$ under vinyl mulching. Leaves and stems for assay were sampled at 100 day after sowing. The obrained results are as follows. 1. Number and dry weight of nodule as well as dry weight of aerial part of peanut plant increased by inoculation with B. sp. and were the highest in calcium carbonate application. 2. Inoculated with B. sp., the contents of T-N, $K_2O$, MgO, allantoin, ammonia, free amino acid and chlorophyll increased, but that of nitrate decreased. 3. The contents of T-N, free amino acid, and chlorophyll were higher in the treatment of calcium carbonate, those of $K_2O$, MgO, allantoin, ammonia were higher in magnesium lime application, and those of CaO and nitrate were higher in slaked lime fertilization than any other lime types. 4. Contents of total sugar and starch in stem at 100 days were higher in the treatment of uninoculation than inoculation with B. sp., and those were highest in the calcium sulfate application than the other lime types. 5. Inoculated with B. sp. length of main stem and number of pods increased significantiy. Yield of seed was higher in inoculation with B. sp. than in uninoculation by 64%, and in the order of carbonate, magnesium lime, slaked lime, in calcium sulfate and non-application was the contribution of soil treatments to yield increases.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.773-782
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• 2007

A total of thirty sows(Landrace×Yorkshire) were used to determine the effects of plant protein source containing multienzyme on performance, nutrients digestibility and milk characteristics. A feeding trial was conducted for 21 days from parturition to weaning. Experimental diets were supplied for 1 week before the parturition day and throughout the experimental period. Dietary treatments included: 1) Control(CON; basal diet), 2) CGLT(included corn gluten) and 3) FSPM(included fermented soy protein containing multienzyme). Through the entire experimental period, backfat loss and return-to-estrus intervals were not affected by the treatments(P>0.05). Nitrogen digestibility was increased significantly(P<0.05) in FSPM treatment compared to CON treatment. Blood urea nitrogen(BUN) concentration was increased significantly (P<0.05) in FSPM treatment compared to CON treatment. At the initial  period, total protein content of milk was higher significantly(P<0.05) in FSPM treatment compared to CGLT treatment and at the final period, total fat content of milk was higher significantly(P<0.05) in FM treatment compared to CON treatment. Rectal temperature showed similar tendency of change among treatments. The final piglet body weight, weight gain and ADG were higher significantly in FSPM treatment compared to CON treatment. On diarrhea rate in piglet, just one piglet occurred in CGLT treatement. In conclusion, 2.5% dietary plant protein source containing multienzyme suppelmentation improved N digestibility, BUN concentration, fat and protein contents in milk and weight gain in piglet.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.510-514
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• 2007

This study was carried on cool and RT(room temperature) storage of unhulled rice. In RT storage of an analysis of coefficient relation, high significant positive coefficients were observed in toyo index and breakdown, setback and protein content. high significant negative coefficients were showed setback and breakdown, breakdown and protein content. In cool storage of an analysis of coefficient relation, high significant positive coefficients were observed in toyo index and amylose content and gelatinization start temperature and protein content and high significant negative coefficients were showed toyo index and whiteness, toyo index and gelatinization start temperature, gelatinization start temperature and amylose content. In RT storage of a path coefficient analysis, a highest positive direct influence was observed in amylose content and a highest negative direct influence was protein content. Positive indirect influence was high revealed breakdown and protein content and negative indirect influence was gelatinization start temperature and Mg/K ratio. In cool storage of a path coefficient analysis, a highest positive direct influence was whiteness and a highest positive indirect influence was gelatinization start temperature. Positive indirect influence was high revealed gelatinization start temperature and amylose content, negative indirect influence was whiteness and gelatinization start temperature. In RT storage of Multiple regression equation of Toyo index based on physicochemical properties of unhulled rice, a highest coefficient of determination was revealed among five facters of whiteness, protein content, Mg/K ratio, amylose content and gelatinization start temperature. In cool storage of Multiple regression equation of toyo index based on physicochemical properties of unhulled rice, highest coefficient of determination was revealed among five facters of moisture content, amylose content, gelatinization start temperature, breakdown and setback.