• Title/Summary/Keyword: G-force

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Experimental and Numerical Study of Berthing and Unberthing of LNG-Bunkering Vessels (실험 및 수치해석을 통한 LNG 벙커링 선박들의 이접안 안정성 평가 연구)

  • Jung, Sung-Jun;Oh, Seung-Hoon;Jung, Dong-Woo;Kim, Yun-Ho;Jung, Dong-Ho
    • Journal of Navigation and Port Research
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    • v.44 no.6
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    • pp.439-446
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    • 2020
  • The IMO has adopted emission standards through Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL) that strictly prohibit the use of bunker C oil for vessels. In this study, we have adopted the turret-moored Floating LNG-Bunkering Terminal (FLBT) which is designed to receive the LNG from LNGCs and transfer it to LNG-bunkering shuttles in side-by-side moored condition. Numerical analyses were carried out using the high-order boundary-element method for four vessels at various relative distances. Mean wave drift forces were compared in an operational sea state. A model test was performed in the ocean engineering basin at the Korea Research Institute of Ships & Ocean Engineering (KRISO) to verify the safety of the berthing/unberthing operation. In the model test, a jig was designed to simulate tug boats pushing or pulling the bunkering vessels, so that the friction force of the g operation was not affected. Safety depended on the environmental direction, with more stable operation possible if the heading-control function of FLBT is applied to avoid beam-sea conditions.

Effects of Microbial Additives and Silo Density on Chemical Compositions, Fermentation Indices, and Aerobic Stability of Whole Crop Rice Silage (미생물 첨가와 사일로 밀도가 총체벼 사일리지의 영양소 함량, 발효특성 및 호기적 안전성에 미치는 영향)

  • Joo, Young Ho;Jeong, Seung Min;Seo, Myeong Ji;Lee, Seong Shin;Choi, Ki Choon;Kim, Sam Churl
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.42 no.2
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    • pp.96-102
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    • 2022
  • The present study investigated effects of microbial additives and silo density on chemical compositions, fermentation indices, and aerobic stability of whole crop rice (WCR) silage. The WCR ("Youngwoo") was harvested at 49.7% dry matter (DM), and ensiled into 500 kg bale silo with two different compaction pressures at 430 kgf (kilogram-force)/cm2 (LOW) and 760 kgf/cm2 (HIGH) densities. All WCR forage were applied distilled water (CON) or mixed inoculants (Lactobacillus brevis 5M2 and Lactobacillus buchneri 6M1) with 1:1 ratio at 1x105 colony forming unit/g (INO). The concentrations of DM, crude protein, ether extract, crude ash, neutral detergent fiber, and acid detergent fiber of whole crop rice before ensiling were 49.7, 9.59, 2.85, 6.74, 39.7, and 21.9%, respectively. Microbial additives and silo density did not affect the chemical compositions of WCR silage (p>0.05). The INO silages had lower lactate (p<0.001), but higher propionate (p<0.001). The LOW silages had higher lactate (p=0.004). The INO silages had higher yeast count (p<0.001) and aerobic stability (p<0.001). However, microbial counts and aerobic stability were not affected by silo density. Therefore, this study concluded that fermentation quality of WCR silage improved by microbial additives, but no effects by silo density.

Recommended levels of calcium and non-phytate phosphorus for yellow-feathered broilers (finisher phase)

  • Wang, Yibing;Wang, Weiwei;Zhang, Sheng;Jiang, Shouqun
    • Animal Bioscience
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    • v.35 no.12
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    • pp.1940-1947
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    • 2022
  • Objective: This study examined the effects of dietary calcium (Ca) and non-phytate phosphorus (NPP) on performance, tibial characteristics, meat quality and plasma biochemical variables in yellow-feathered broilers during 85 to 105 d of age. Methods: A total of 720 heads of 85-d broilers were allocated into 9 groups and provided with three levels of Ca (0.65%, 0.75%, 0.85%), and NPP (0.25%, 0.30%, 0.35%) in diets for 21 d. Results: The final body weight (FW), average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (F:G) were affected (p<0.05) by dietary Ca. From the quadratic regressions, the optimal level of Ca in diet were 0.71% for FW and ADG, and 0.67% for ADFI. Dietary Ca and NPP both significantly affected tibial breaking strength and density. From the quadratic regressions, the optimal level of Ca and NPP in diet were 0.81% and 0.37% for tibial density. The shear force of breast muscle of broilers given 0.75% or 0.85% Ca were lower than that in birds with 0.65% Ca and drip loss of birds given 0.65% or 0.75% Ca was lower than that in birds with 0.85% Ca (p<0.05). The drip loss of birds given 0.25% NPP was lowest among all NPP treatments (p<0.05). Calcium affected (p<0.05) the plasmal contents of phosphorus, osteocalcin (OC), parathyroid hormone (PTH) and calcitonin and the contents of OC and PTH were also influenced by dietary NPP. Conclusion: Dietary Ca and NPP level affected tibial characteristics, meat quality and biochemical variables in plasma of finisher-phase yellow-feathered broilers (85 to 105 d) and Ca also affected growth performance. Dietary 0.71% Ca and 0.30% NPP were enough for growth performance, while considering the growth performance, tibial characteristics, meat quality and biochemical variables together, 0.75% Ca and 0.37% NPP were recommended.

Current Status and Dietitians' Perception of Rice Bread in the Noncommercial Foodservice Menu (단체급식 식단의 쌀빵 이용 현황 및 영양사의 인식 분석)

  • Cha, Sung-Mi;Lee, Min-A;Lee, Hae-Young;Lee, So-Jung;Yang, Il-Sun
    • Journal of the Korean Society of Food Culture
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    • v.23 no.3
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    • pp.356-365
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    • 2008
  • The purpose of this study was to survey the current status of bread menus at school, business and industry (B & I), and military foodservice operations and to analyze dietitians' perceptions of applying rice bread in foodservice menus. A questionnaire, which was developed by content analysis, situation analysis, and in-depth interview, was distributed to 183 schools, 31 B & I operations, and 26 air force dietitians. In the school and B & I foodservices, wheat bread was used much more than rice bread and serving frequencies of morning rolls and sliced bread were higher. The military foodservices, however, served much more rice bread as burger buns than the other groups. For the school and B&I operations, consumer preference for wheat bread was perceived as high. In contrast, soldiers preferred rice bread to wheat bread in the military foodservices. The recognized advantages of using rice bread were different among the three groups. The military dietitians perceived the main advantage of using rice bread as an increase of rice consumption, while the school and B & I dietitians viewed it as promoting a healthy image. In all groups, the primary difficulties for using rice bread were the higher cost of rice bread as compared to wheat bread and a lack of facilities (e.g. oven). The military dietitians had the highest levels of positive and active interest as well as intention and opinions toward using rice bread. On the other hand, the school and B & I dietitians had very positive perceptions of rice bread but did not actually apply it in their foodservice menus. Overall, the results of this study suggest that the development of diverse menus using rice bread along with government support of its use, including facilities with ovens as well as rice bread subsidies, should be carried out for on-going expansion of the rice bread supply.

Development of an Effective Method to Evaluate Resistance of Onion (Allium cepa L.) Cultivars to Fusarium Basal Rot (양파 유묘기 단계 시들음병(Fusarium Basal Rot) 저항성 검정법 개발)

  • Sieun Kim;Jong-Hwan Shin;Ha-Kyoung Lee;Soo-hyun Kang;Ji-won Han;Seong-Chan Lee;You-Kyoung Han
    • Research in Plant Disease
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    • v.30 no.3
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    • pp.288-293
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    • 2024
  • Fusarium basal rot (FBR), caused by the ascomycete fungus Fusarium oxysporum, is an economically important disease of onion worldwide. The most economical and effective way to manage FBR would be the use of FBR resistant onion cultivars. This study was carried out to develop a rapid screening method for resistant onion cultivars in seedling stage. We used the F. oxysporum 19-385 isolate, which causes damping-off in onion seedlings and basal rot in onion bulbs. We optimized broth incubation and medium composition for the production of inoculum, and determined conidial concentration for the preparation of F. oxysporum infected soil. Ten commercial cultivars of onion were evaluated the seedling survival rates and heights by infected soil inoculation methods. As a result, 'K-force' was the most resistant cultivar with 97.4% of relative seedling survival rate against the pathogen, whereas 'Sunpower' was the most susceptible cultivar with 20.0% of relative seedling survival rate.

Using the METHONTOLOGY Approach to a Graduation Screen Ontology Development: An Experiential Investigation of the METHONTOLOGY Framework

  • Park, Jin-Soo;Sung, Ki-Moon;Moon, Se-Won
    • Asia pacific journal of information systems
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    • v.20 no.2
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    • pp.125-155
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    • 2010
  • Ontologies have been adopted in various business and scientific communities as a key component of the Semantic Web. Despite the increasing importance of ontologies, ontology developers still perceive construction tasks as a challenge. A clearly defined and well-structured methodology can reduce the time required to develop an ontology and increase the probability of success of a project. However, no reliable knowledge-engineering methodology for ontology development currently exists; every methodology has been tailored toward the development of a particular ontology. In this study, we developed a Graduation Screen Ontology (GSO). The graduation screen domain was chosen for the several reasons. First, the graduation screen process is a complicated task requiring a complex reasoning process. Second, GSO may be reused for other universities because the graduation screen process is similar for most universities. Finally, GSO can be built within a given period because the size of the selected domain is reasonable. No standard ontology development methodology exists; thus, one of the existing ontology development methodologies had to be chosen. The most important considerations for selecting the ontology development methodology of GSO included whether it can be applied to a new domain; whether it covers a broader set of development tasks; and whether it gives sufficient explanation of each development task. We evaluated various ontology development methodologies based on the evaluation framework proposed by G$\acute{o}$mez-P$\acute{e}$rez et al. We concluded that METHONTOLOGY was the most applicable to the building of GSO for this study. METHONTOLOGY was derived from the experience of developing Chemical Ontology at the Polytechnic University of Madrid by Fern$\acute{a}$ndez-L$\acute{o}$pez et al. and is regarded as the most mature ontology development methodology. METHONTOLOGY describes a very detailed approach for building an ontology under a centralized development environment at the conceptual level. This methodology consists of three broad processes, with each process containing specific sub-processes: management (scheduling, control, and quality assurance); development (specification, conceptualization, formalization, implementation, and maintenance); and support process (knowledge acquisition, evaluation, documentation, configuration management, and integration). An ontology development language and ontology development tool for GSO construction also had to be selected. We adopted OWL-DL as the ontology development language. OWL was selected because of its computational quality of consistency in checking and classification, which is crucial in developing coherent and useful ontological models for very complex domains. In addition, Protege-OWL was chosen for an ontology development tool because it is supported by METHONTOLOGY and is widely used because of its platform-independent characteristics. Based on the GSO development experience of the researchers, some issues relating to the METHONTOLOGY, OWL-DL, and Prot$\acute{e}$g$\acute{e}$-OWL were identified. We focused on presenting drawbacks of METHONTOLOGY and discussing how each weakness could be addressed. First, METHONTOLOGY insists that domain experts who do not have ontology construction experience can easily build ontologies. However, it is still difficult for these domain experts to develop a sophisticated ontology, especially if they have insufficient background knowledge related to the ontology. Second, METHONTOLOGY does not include a development stage called the "feasibility study." This pre-development stage helps developers ensure not only that a planned ontology is necessary and sufficiently valuable to begin an ontology building project, but also to determine whether the project will be successful. Third, METHONTOLOGY excludes an explanation on the use and integration of existing ontologies. If an additional stage for considering reuse is introduced, developers might share benefits of reuse. Fourth, METHONTOLOGY fails to address the importance of collaboration. This methodology needs to explain the allocation of specific tasks to different developer groups, and how to combine these tasks once specific given jobs are completed. Fifth, METHONTOLOGY fails to suggest the methods and techniques applied in the conceptualization stage sufficiently. Introducing methods of concept extraction from multiple informal sources or methods of identifying relations may enhance the quality of ontologies. Sixth, METHONTOLOGY does not provide an evaluation process to confirm whether WebODE perfectly transforms a conceptual ontology into a formal ontology. It also does not guarantee whether the outcomes of the conceptualization stage are completely reflected in the implementation stage. Seventh, METHONTOLOGY needs to add criteria for user evaluation of the actual use of the constructed ontology under user environments. Eighth, although METHONTOLOGY allows continual knowledge acquisition while working on the ontology development process, consistent updates can be difficult for developers. Ninth, METHONTOLOGY demands that developers complete various documents during the conceptualization stage; thus, it can be considered a heavy methodology. Adopting an agile methodology will result in reinforcing active communication among developers and reducing the burden of documentation completion. Finally, this study concludes with contributions and practical implications. No previous research has addressed issues related to METHONTOLOGY from empirical experiences; this study is an initial attempt. In addition, several lessons learned from the development experience are discussed. This study also affords some insights for ontology methodology researchers who want to design a more advanced ontology development methodology.

Design Factor Analysis of End-Effector for Oriental Melon Harvesting Robot in Greenhouse Cultivation (시설재배 참외 수확 로봇용 엔드이펙터의 설계 요인 분석)

  • Ha, Yu Shin;Kim, Tae Wook
    • Journal of Bio-Environment Control
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    • v.22 no.3
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    • pp.284-290
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    • 2013
  • This study analyzed the geometric, compressive, cutting and friction properties of oriental melons in order to design a gripper capable of soft handling and a cutter for cutting oriental melon vine among the end effector of oriental melon as a preliminary step for developing the end effector of the robot capable of harvesting oriental melons in protected cultivation. As a result, the average length, diameter at the midpoint, weight, volume and roundness of the oriental melons were 108 mm, 70 mm, 188 g, 333 mL and 3.8 mm. Nonlinear regression analysis was performed on the equation $W=L^a{\times}D_2^b$ with variation of the length (L) and diameter (D2) of the weight (W) of the oriental melons. As a result, it was shown that there was a correlation between a of 2.0279 and b of -0.9998 as a constant value. The average diameter of the oriental melon vine was 3.8 mm, and most vines were distributed within a radius of 5 mm from the center. The average yield value, compressive strength and hardness of the oriental melons were $36.5N/cm^2$, $185.7N/cm^2$ and $636.7N/cm^2$, respectively. The average cutting force and shear strength of the oriental melon vines were $2.87{\times}10^{-2}\;N$ and $5.60N/cm^2$, respectively. The maximum friction coefficient of the oriental melons was rubber of 0.609, followed by aluminium of 0.393, stainless steel of 0.177 and teflon of 0.079. It was considered possible to apply it to the size of the gripper and cutter, turning radius, dynamics of drive motor and selection of materials and their quality in light of the position error and safety factor according to the movement when designing end effector based on the analyzed data.

Bone-implant contact and mobility of surface-fronted orthodontic micro-implants in dogs (성견에서 표면처리된 교정용 마미크로 임플랜트의 골 접촉률 및 동요도)

  • Park, Seung-Hyun;Kim, Seong-Hun;Ryu, Jun-Ha;Kang, Yoon-Goo;Chung, Kyu-Rhim;Kook, Yoon-Ah
    • The korean journal of orthodontics
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    • v.38 no.6
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    • pp.416-426
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    • 2008
  • The purpose of this study was to evaluate the mobility and ratio of the bone-implant contact (BIC) of a sandblasted, large grit and acid-etched (SLA) orthodontic micro-implant. Methods: Ninety-six micro-implants (48 SLA and 48 machined) were implanted in the upper and lower buccal alveolar bone, and palatal bone of four beagle dogs. Two weeks after surgery, orthodontic force (150-200 g) was applied. Two beagles were sacrificed at 4-weeks and the other two at 12-weeks. Histomorphometric comparisons were made between the SLA experimental group and the machined micro-implant as a control group to determine the ratio of contact between the bone and implant. Micro-implant mobility was also evaluated using $Periotest^{(R)}$. Results: Periotest values showed no statistically significant difference in the upper alveolar and palatal bone between groups except for the lower buccal area. BIC in the upper buccal area showed no significant difference between groups both at 4-weeks and 12-weeks. However, both the groups showed a significant difference in BIC ratio in the rest of the experimental areas between 4 weeks and 12 weeks. The experimental group showed active bone remodeling around the bone-implant interface compared to the control group. Conclusions: There were significant differences in the BIC and the Periotest values between the surface-treated and machined micro-implants according to bone quality in the early stage.

The Pattern of Initial Displacement in Lingual Lever Arm Traction of 6 Maxillary Anterior Teeth According to Different Material Properties: 3-D FEA (유한요소모델에서 레버암을 이용한 상악 6전치 설측 견인 시 초기 이동 양상)

  • Choi, In-Ho;Cha, Kyung-Suk;Chung, Dong-Hwa
    • Journal of Dental Rehabilitation and Applied Science
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    • v.24 no.2
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    • pp.213-230
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    • 2008
  • The aim of this study was to analyze the initial movement and the stress distribution of each tooth and periodontal ligament during the lingual lever-arm retraction of 6 maxillary incisors using FEA. Two kinds of finite element models were produced: 2-properties model (simple model) and 24-properties model (multi model) according to the material property assignment. The subject was an adult male of 23 years old. The DICOM images through the CT of the patient were converted into the 3D image model of a skull using the Mimics (version 10.11, Materialise's interactive Medical Image Control System, Materialise, Belgium). After series of calculating, remeshing, exporting, importing process and volume mesh process was performed, FEA models were produced. FEA models are consisted of maxilla, maxillary central incisor, lateral incisor, canine, periodontal ligaments and lingual traction arm. The boundary conditions fixed the movements of posterior, sagittal and upper part of the model to the directions of X, Y, Z axis respectively. The model was set to be symmetrical to X axis. Through the center of resistance of maxilla complex, a retraction force of 200g was applied horizontally to the occlusal plane. Under this conditions, the initial movements and stress distributions were evaluated by 3D FEA. In the result, the amount of posterior movement was larger in the multi model than in the simple model as well as the amount of vertically rotation. The pattern of the posterior movement in the central incisors and lateral incisors was controlled tipping movement, and the amount was larger than in the canine. But the amount of root movement of the canine was larger than others. The incisor rotated downwardly and the canines upwardly around contact points of lateral incisor and canine in the both models. The values of stress are similar in the both simple and multi model.

Removable implant-supported partial denture using milled bar with Locator® attachments in a cleft lip & palate patient: A clinical report (구순구개열 환자에서 Locator® 유지장치가 장착된 milled titanium bar를 이용한 가철성 임플란트 피개 국소의치의 보철수복증례)

  • Yang, Sang-Hyun;Kim, Kyoung-A;Kim, Ja-Yeong;Seo, Jae-Min
    • The Journal of Korean Academy of Prosthodontics
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    • v.53 no.3
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    • pp.207-214
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    • 2015
  • Due to the limitations of conventional removable partial denture prostheses to treat a cleft lip & palate patient who shows scar tissue on upper lip, excessive absorption of the maxillary residual alveolar ridge, and class III malocclusion with narrow palate and undergrowth of the maxilla, 4 implants were placed on the maxillary edentulous region and a maxillary removable implant-supported partial denture was planned using a CAD/CAM milled titanium bar. Unlike metal or gold casting technique which has shrinkage after the molding, CAD/CAM milled titanium bar is highly-precise, economical and lightweight. In practice, however, it is very hard to obtain accurate friction-fit from the milled bar and reduction in retention can occur due to repetitive insertion and removal of the denture. Various auxiliary retention systems (e.g. $ERA^{(R)}$, $CEKA^{(R)}$, magnetics, $Locator^{(R)}$ attachment), in order to deal with these problems, can be used to obtain additional retention, cost-effectiveness and ease of replacement. Out of diverse auxiliary attachments, $Locator^{(R)}$ has characteristics that are dual retentive, minimal in vertical height and convenient of attachment replacement. Drill and tapping method is simple and the replacement of the metal female part of $Locator^{(R)}$ attachment is convenient. In this case, the $Locator^{(R)}$ attachment is connected to the milled titanium bar fabricated by CAD/CAM, using the drill and tapping technique. Afterward, screw holes were formed and 3 $Locator^{(R)}$ attachments were secured with 20 Ncm holding force for additional retention. Following this procedure, satisfactory results were obtained in terms of aesthetic facial form, masticatory function and denture retention, and I hereby report this case.