• Title/Summary/Keyword: cause of the decline

Search Result 222, Processing Time 0.033 seconds

A Development of Unbalanced Box Stacking System with High Stability using the Center of Gravity Measurement (무게중심 측정을 이용한 불평형 상자의 고안정 적재 시스템 개발)

  • Seong-Woo Bae;Dae-Gyu Han;Jae-Ho Ryu;Hyeon-hui Lee;Chae-Hun An
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.27 no.1
    • /
    • pp.229-237
    • /
    • 2024
  • The logistics industry is converging with digital technology and growing into various logistics automation systems. However, inspection and loading/unloading, which are mainly performed in logistics work, depend on human resources, and the workforce is shrinking due to the decline in the productive population due to the low birth rate and aging. Although much research is being conducted on the development of automated logistics systems to solve these problems, there is a lack of research and development on load stacking stability, which has the potential to cause significant accidents. In this study, loading boxes with various sizes and positions of the center of gravity were set up, and a method for stacking that with high stability is presented. The size of the loading box is measured using a depth camera. The loading box's weight and center of gravity are measured and estimated by a developed device with four loadcells. The measurement error is measured through various repeated experiments and is corrected using the least squares method. The robot arm performs load stacking by determining the target position so that the centers of gravity of the loading boxes with unbalanced masses with a random sequence are transported in alignment. All processes were automated, and the results were verified by experimentally confirming load stacking stability.

Variation in Breeding Burrows of Streaked Shearwaters Breeding in Sasu Island, and Predation Rates by Norway Rats (사수도에 번식하는 슴새의 둥지 사용률의 변화 및 집쥐의 포식률)

  • Nam, Ki-Baek;Lee, Kyung-Gyu;Hwang, Jae-Woong;Yoo, Jeong-Chil
    • Ocean and Polar Research
    • /
    • v.36 no.1
    • /
    • pp.49-57
    • /
    • 2014
  • The seabird plays an important role as one of the indicator species for the status of and changes within marine ecosystems. Therefore, the conservation of seabirds and their habitats is important for maintaining the structure and function of marine ecosystems. Biological invasions affect most ecosystems on oceanic islands. In particular, Rattus spp. is the invasive species with the greatest impact on the seabird population. Introduced predators, like rats, severely affect seabirds and endanger them worldwide. The breeding population of Streaked Shearwaters Calonectris leucomelas in Sasu Island is one of biggest seabird colonies in Korea, and the Norway Rat Rattus norvegicus is known as an alien predator in this island. In this study we investigated rates of burrow occupancy and breeding success of Streaked Shearwaters for 7 years, and the impact of Norway Rats on the breeding success of Streaked Shearwaters breeding in Sasu Island for 4 years. Our results show that the percentage of breeding burrows decreased according to breeding stage during several years in the monitoring period, and that predation by the Norway Rat was the main cause in hatching failures. Consequently, although our results indicate that their breeding population is not likely to decline, Norway Rats have been affecting the breeding status of Streaked Shearwaters on Sasu Island during the last decade.

Analysing the Influence of Technology on the Business Performance of Rattan Processing SME's in South Kalimantan

  • Wiratmadja, Iwan Inrawan;Govindaraju, Rajesri;Setiawati, Evy
    • Industrial Engineering and Management Systems
    • /
    • v.10 no.2
    • /
    • pp.104-108
    • /
    • 2011
  • Technology is one of the major competitive advantages for small and medium enterprises (SME), especially ones operating in the manufacturing sector. Increasing technological capabilities is the basis for SME's business performance improvement. The main problem of SME's is a limitation in the areas of production facilities, technology, and human resources. Some of these constraints cause a decline in business performance and competitiveness of SME's. In this case analysis of technology components has to be carried out to determine the effect of technology on SME's business performance improvement. This study aims to measure the components of technology and to analyze the influence of each technology component on business performance of rattan processing SME's in South Kalimantan. The assessment is carried out on the technoware, humanware, inforware, and orgaware components using the technometric method (UNESCAP). Business performance is measured through a combination of financial and non-financial aspects deducted from financial and marketing figures. Analysis of the influence of technology components on business performance of SME's is done using the Structural Equation Model (SEM) with Partial Least Square software (PLS). Data is collected through interviews and questionnaires from 21 rattan processing SME's in South Kalimantan that produce rattan furnitures. The results show that the value of the contribution of technology (TCC) to the performance of rattan processing SME's in South Kalimantan is still quite low. Analysis of the results shows a direct influence of technoware and humanware on business performance, while orgaware influences business performance indirectly through humanware.

Exploring the Relationship between Designating of Disaster Preventing Zones and Land Prices - The Case of Seoul (방재지구의 지정과 토지가격과의 상관성 분석 -서울특별시 방재지구를 중심으로)

  • Kim, Ja Eun;Lee, Sung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.40 no.3
    • /
    • pp.295-302
    • /
    • 2020
  • Disaster Preventing Zone (DPZ) is one of the zoning for land use regulation. Though the purpose of the designating of DPZs is to improve the area be safer, people has the negative recognition on DPZs. They think DPZs are regulation to restrict the actions and finally causes decrease on the land price. In this context, the aim of this study is to investigate the correlation between the designation of the DPZs and the land price of the DPZs in Seoul Metropolitan City. We applied the Difference in different (DID) which is one of the research methods to verify the cause and effect of specific policy. As a result, it was found statistically significant that land price of parcels designated as DPZs was 420,000 won higher than those not designated. The same results were obtained when the land characteristics were added, and the robustness of the model was indirectly confirmed. Based on the results, the designating of the DPZs was contrary to the expectation. Although it is necessary to analyze the result of the study more microscopically, It will be necessary to change the perception that it will decline.

Characteristics of milk fever and mastitis following different milking method and preventive calcium injection performed during the colostrum period in dairy cattle

  • Jeon, Ryounghoon
    • Journal of Animal Reproduction and Biotechnology
    • /
    • v.35 no.3
    • /
    • pp.273-278
    • /
    • 2020
  • The milk fever and mastitis that occur during the colostrum period in dairy cattle cause great damage in the dairy industry by causing a rapid decline in the cattle's health and decreasing milk production. In order to prevent this, gradual milking (GM), calcium injection with gradual milking (CG), and calcium injection with complete milking (CC) methods are used. However, differences in effectiveness between these methods have not been established. Therefore, this study was conducted to determine the effects of each preventive method on milk fever and mastitis. The results of this study showed that while there was a significant negative correlation of GM with milk fever and mastitis (r = -0.657, p < 0.05), there was no correlation of CG and CC with milk fever and mastitis. The incidence of milk fever was significantly lower in CG and CC than in GM (p < 0.05) but no differences in the incidence of mastitis were observed between the three groups. No significant differences in the rate of recovery from milk fever and mastitis were observed between the three groups. The recurrence rate of milk fever was significantly higher in CG and CC than in GM (p < 0.05), though no differences in the recurrence rate of mastitis were observed. This study showed an inverse relationship between the incidence rates of milk fever and mastitis when calcium injection was not used during the colostrum period. When calcium injections were used, the incidence of milk fever was reduced without affecting the incidence of mastitis regardless of the milking method, but the recurrence rate of milk fever was increased. The results of this study would be useful for controlling blood calcium concentrations and establishing efficient milking strategy in order to effectively prevent milk fever and mastitis in dairy cattle during the colostrum period.

Effects of Skin Pressure by All-in-one on the Rhythm of Body Temperature During Sleep (올인원에 의한 인체 압박이 수면시의 체온 리듬에 미치는 영향)

  • Jeong, Jeong-Rim;Kim, Hee-Eun
    • Fashion & Textile Research Journal
    • /
    • v.12 no.6
    • /
    • pp.830-836
    • /
    • 2010
  • The purpose of this research was to investigate the effects of skin pressure by wearing all-in-one on the rhythm of body temperature such as skin and rectal temperature which play a crucial role in the nocturnal rhythm. Five healthy female were participated in the study as subjects. The experimental clothing was an all-in-one, one of the foundation, which is worn for shaping the body. The total experimental periods were 5 days. On the 1st day, subjects did not wear the all-in-one (None), and they wore it for about 12 hours per day from 2nd to 5th day (Wearing1~4). Skin and rectal temperature were measured during the entire experimental days to figure out the rhythm of body temperature during sleep. When subjects wore the all-in-one, the gradients of the forearm and calf skin temperature at the sleep onset were significantly smaller than "None". It indicated that the rise of extremities' skin temperature was low on the "Wearing1~4". The decline of rectal temperature in "Wearing 1~4" was smaller than "None". Therefore, the skin pressure by all-in-one may cause the temperature of extremities' skin and rectum to change, resulting the fluctuation of the circadian rhythm, finally it could have effects on the rhythm of sleep.

Changes of the Plant Community Structure during the Twenty-two Years(1972~1993) in Forest of Mt. Kwanak (관악산 삼림의 22년간(1972~1993)의 식물군집구조 변화)

  • Lee, Kyong-Jae;Song, Keun-Joon;Cho, Woo
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.22 no.3
    • /
    • pp.79-90
    • /
    • 1994
  • This survey was ocnducted to investgate changes of the plant community structure from 1972 to 1993 in forest of Mt. Kwanak and thirty-five plots that the size of each plot was 10m${\times}$10m(100㎡) were set up and the vegetation analysis was caried out. By the TWINSPAN analysis, the plant community of survey area were divied into Quercus mongolica, Q. mongolica-Pinus densiflora(1), Q. mongolica-P. densiflora(2), Q. acutissima community. The successional trends of the woody species were seemed to be from P. densiflora, Sorbus alnifolia to Q. mongolica in the canopy layer. But the successional trends in the understory and shrub layer were difficult to suppose. The forest vegetation of Mt. Kwanak from 1972 to 1993 was severely decreased in species number and individuals. The sensitive species for the environmental pollution were selected, and the tolerant plants for the acid soil were increased. In comparision with the DBH class distribution from 1972 to 1993, it shows that the ecological succession has stopped. In the analysis of soil characteristics, soil acidification has taken place over last twenty-two years(from pH=5.40 to pH=4.53). The concentration of K+, Ca++ was severly decreased(from K+=0.60m.e./100g to K+=0.06m.e./100g, from Ca++=3.20m.e./100g to Ca++=0.63m.e./100g), which also could seemed to be cause of plant community decline.

  • PDF

Cases Study of Accidents in High Risk Organizations by System Dynamics (시스템 다이내믹스 기법을 활용한 고위험 조직 사고 사례 분석)

  • Oh, Youngmin;Ryu, Jin
    • Korean System Dynamics Review
    • /
    • v.16 no.3
    • /
    • pp.5-29
    • /
    • 2015
  • The importance of the concept of safety culture has increased in the security of high-risk facility after Chernobyl accident in 1986. This paper elaborated the concept of safety culture and its main factors by Causal Loop Diagram. Due to the decline of safety culture, the occurrence of incidents and accidents require more and more corrective actions to the members of high-risk facilities and thereby increasing their workloads. Employees who must complete the task within the given time have to have time pressures and don't comply with the rules and procedures. Also, a schedule pressure is a big stress for employees, causing mistakes in precision work. In order to improve these problems, CLD of the safety culture in this paper suggests hiring more workers, re-allocation of given workloads and strengthen the learning, communication capabilities and safety leadership. In addition, the two real accident cases were analyzed to test the feasibility of the System Dynamic simulation model through the process of structuring the fault trees on the stationary black out accident in Kori unit 1 in South Korea and Kleen Energy power station explosion in US. The simulation results show that the various safety factors cause the serious accident combined with mechanical failure and safety culture will reduce the possibility of the accidents in these high-risk organizations. This simulation model can contribute to analyzing the impact of the organizational and human factors of safety culture and can provide the alternatives in high-risk facilities.

The Slough of Cicadidae Periostracum Ameliorated Lichenification by Inhibiting Interleukin (IL)-22/Janus Kinase (JAK) 1/Signal Transducer and Activator of Transcription (STAT) 3 Pathway in Atopic Dermatitis

  • Ganghye Park;Namgyu Kwon;Mi Hye Kim;Woong Mo Yang
    • Food Science of Animal Resources
    • /
    • v.43 no.5
    • /
    • pp.859-876
    • /
    • 2023
  • It is known that animal-origin medicine could be one of effective treatment to remedy atopic dermatitis (AD) by controlling the cytokines. Cicadidae Periostracum (CP), the slough of Cryptotympana pustulata, has been frequently used for treating AD and skin affliction in traditional Korean Medicine. This study is aimed at investigating the ameliorating effects of CP on AD and its potential mechanism. The dinitrochlorobenzene sensitized mice were treated with CP for 2 weeks. The various biomarkers and the dermatitis scores presented that CP treatment can induce the visual and biological improvements of AD model. Pruritus, the most serious symptom of AD, which can cause repeated scratching behaviors and finally lead to lichenification, was reduced with CP treatment by regulating the inflammatory reactions. In addition, CP treatment diminished the number of mast cells that are known for causing inflammatory reactions. Moreover, it is proven that CP can decline secretion of interleukin-22, which means CP treatment has anti-inflammatory effects. CP treatment can correct the imbalance of helper T (Th)1 and Th2, downregulating thymic stromal lymphopoietin that leads to decrease of mRNA level of inflammatory cytokines. The crucial role of CP treatment is controlling of the Janus kinase 1/signal transducer and activator of transcription 3 pathway. In addition, CP treatment has the inhibitory effects on kallikrein related peptidase (KLK) 5 and KLK7. Taken together, CP treatment can ameliorate most symptoms and problems caused by AD disease, improving the AD patients' life quality.

Experimental Study on Natural Gas Conversion Vehicle(1) - Fuel Economy, Emission and Roadability (천연가스 개조 승용차에 대한 실험적 연구(1) - 연비, 배기 및 주행 성능)

  • Kim, Hyung-Gu;Kim, Inok;Ohm, Inyong
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.23 no.4
    • /
    • pp.410-419
    • /
    • 2015
  • In this study, the roadability, fuel economy and emission characteristics were evaluated for a natural gas converted vehicle. The results are as follows; Not only the shortage of power was observed in stall test, but also large deterioration of acceleration performance was exposed in roadability. Compared to the original LPG system, the acceleration is 76% in start acceleration and 45 ~ 65% in overtaking acceleration, especially the decline became larger when air conditioner is at work. Furthermore, because the mapping data, which controls the injection depending on driving condition, do not match up with injection system, the failure of air-fuel ratio feedback control occurs resulting from the large gap between the required and the really supplied amount of fuel. This failure cause the exhaust gas to emit without catalytic conversion and the fuel economy based on the fuel heat value to get worse 22% in the mode test and 16% in road test respectively. In addition, the existing injection system does not secure enough fuel at the starting so that it may lead to the fail of clod start, the deterioration of hot start and inharmonic of engine at the idle after start.