• Title/Summary/Keyword: surrogate

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A surrogate model-based framework for seismic resilience estimation of bridge transportation networks

  • Sungsik Yoon ;Young-Joo Lee
    • Smart Structures and Systems
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    • v.32 no.1
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    • pp.49-59
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    • 2023
  • A bridge transportation network supplies products from various source nodes to destination nodes through bridge structures in a target region. However, recent frequent earthquakes have caused damage to bridge structures, resulting in extreme direct damage to the target area as well as indirect damage to other lifeline structures. Therefore, in this study, a surrogate model-based comprehensive framework to estimate the seismic resilience of bridge transportation networks is proposed. For this purpose, total system travel time (TSTT) is introduced for accurate performance indicator of the bridge transportation network, and an artificial neural network (ANN)-based surrogate model is constructed to reduce traffic analysis time for high-dimensional TSTT computation. The proposed framework includes procedures for constructing an ANN-based surrogate model to accelerate network performance computation, as well as conventional procedures such as direct Monte Carlo simulation (MCS) calculation and bridge restoration calculation. To demonstrate the proposed framework, Pohang bridge transportation network is reconstructed based on geographic information system (GIS) data, and an ANN model is constructed with the damage states of the transportation network and TSTT using the representative earthquake epicenter in the target area. For obtaining the seismic resilience curve of the Pohang region, five epicenters are considered, with earthquake magnitudes 6.0 to 8.0, and the direct and indirect damages of the bridge transportation network are evaluated. Thus, it is concluded that the proposed surrogate model-based framework can efficiently evaluate the seismic resilience of a high-dimensional bridge transportation network, and also it can be used for decision-making to minimize damage.

Production of Cloned Miniature Pig by Surrogate Mother Conditions (대리모의 준비 조건 변화를 통한 복제미니돼지의 생산)

  • Hur, Chang-Gi;Yang, Hae-Young;Lee, Eun-Kyeong;Han, Joo-Hee;Park, Chun-Gyu;Shin, Teak-Soon;Lee, Hong-Gu;Kang, Han-Seok;Ahn, Jong-Deok;Cho, Seong-Keun
    • Journal of Embryo Transfer
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    • v.27 no.1
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    • pp.1-7
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    • 2012
  • Somatic cell nuclear transfer (SCNT) for miniature pig has been developed for xenotransplantation and many other biomedical experiments. However, the efficiency of SCNT is still very low due to many factors. To optimize the surrogate mother condition for improvement of cloned miniature pigs efficiency, we investigated the effect of the status of surrogate mother on pregnancy, farrowed rate in SCNT pigs. After SCNT with mesenchymal stem cells as donor cells, the SCNT embryos were surgically transferred into the oviduct of surrogated pigs. To compare the effects of status of surrogate pigs on pregnancy, surrogate pigs were prepared by artificial abortion at day 20~29 (Group 1), 30~39 (Group 2), and 40~45 (Group 3) of gestation. After SCNT embryos transfer in three different status of surrogate pigs, Group 2 (56.3%) and 3 (55.6%) had significantly ($p$ <0.05) higher the pregnancy rate than group 1 (0%) at day 30 of gestation. The status of ovulation in surrogate pig also was investigated. Post-ovulation status (54.8%) had higher proportion than pre-ovulation status (38.7%) and ovulation status (6.5%). We obtained 19 cloned miniature piglets from seven surrogate gilts and five piglets are living healthy but fourteen piglets died soon after birth or stillbirth. The weights of piglets greatly differ from 254 to 1,296 g. Microsatellite analysis showed that cloned piglets were genetically different from the surrogate mother and cloned piglets were genetically equal to the donor cell. In conclusion, the present result indicates that artificially abortion method can improve the efficiency of pregnancy after SCNT in pigs. This study will provide available method for the further study and application in the field of xenotransplantation.

Surrogate Internet Shopping Malls: The Effects of Consumers' Perceived Risk and Product Evaluations on Country-of-Buying-Origin Image (망상대구점(网上代购店): 소비자감지풍험화산품평개대원산국형상적영향(消费者感知风险和产品评价对原产国形象的影响))

  • Lee, Hyun-Joung;Shin, So-Hyoun;Kim, Sang-Uk
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.208-218
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    • 2010
  • Internet has grown fast and become one of the most important retail channels now. Various types of Internet retailers, hereafter etailers, have been introduced so far and as one type of Internet shopping mall, 'surrogate Internet shopping mall' has been prosperous and attracting consumers in the domestic market. Surrogate Internet shopping mall is a unique type of etailer that globally purchases well-known brand goods that are not imported in the market, completes delivery in the favor of individual buyers, and collects fees for these specific services. The consumers, who are usually interested in purchasing high-end and unique but not eligible brands, have difficulties to purchase these items overseas directly from the retailers or brands in other countries due to worries of payment failure and no address available for their usually domestic only delivery. In Korea, both numbers of surrogate Internet shopping malls and the magnitude of sales have been growing rapidly up to more than 430 active malls and 500 billion Korean won in 2008 since the population of consumers who want this agent shopping service is also expending. This etail business concept is originated from 'surrogate-mediated purchase' and this type of shopping agent has existed in many different forms and also in wide ranges of context level for quite a long time. As marketers face their individual buyers' representatives instead of a direct contact with them in many occasions, the impact of surrogate shoppers on consumer's decision making has been enormously important and many scholars have explored various range of agent's impact on consumer's purchase decisions in marketing and psychology field. However, not much rigorous research in the Internet commerce has been conveyed yet. Moreover, since as one of the shopping agent surrogate Internet shopping malls specifically connect overseas brands or retailers to domestic consumers, one specific character of the mall's, image of surrogate buying country, where surrogate purchases are conducted in, may play an important role to form consumers' attitude and purchase intention toward products. Furthermore it also possibly affects various dimensions of perceived risk in consumer's information processing. However, though tremendous researches have been carried exploring the effects of diverse dimensions of country of origin, related studies in Internet context has been rarely executed. There have been some studies that prove the positive impact of country of origin on consumer's evaluations as one of information clues in product manufacture descriptions, yet studies detecting the relationship between country image of surrogate buying origin and product evaluations rarely undertaken regarding this specific mall type. Thus, the authors have found it well-worth investigating in this specific retail channel and explored systematic relationships among focal constructs and elaborated their different paths. The authors have proven that country image of surrogate buying origin in the mall, where surrogate malls purchase products in and brings them from for buyers, not only has a positive effect on consumers' product evaluations including attitude and purchase intention but also has a negative effect on all three dimensions of perceived risk: product-related risk, shipping-related risk, and post-purchase risk. Specifically among all the perceived risk, product-related risk which is arisen from high uncertainty of product performance is most affected (${\beta}$= -.30) by negative country image of surrogate buying origin, and also shipping-related risk (${\beta}$= -.18) and post-purchase risk (${\beta}$= -.15) get influenced in order. Its direct effects on product attitude (${\beta}$= .10) and purchase intention (${\beta}$= .14) are also secured. Each of perceived risk dimension is proven to have a negative effect on purchase intention through product attitude as a mediator (${\beta}$= -.57: product-related risk ${\rightarrow}$ product attitude; ${\beta}$= -.24: shipping-related risk ${\rightarrow}$ product attitude; ${\beta}$= -.44: post-purchase risk ${\rightarrow}$ product attitude) as well. From the additional analysis, the paths of consumers' information processing are shown to be different based on their levels of product knowledge. While novice consumers with low level of knowledge consider only perceived risk important, expert consumers with high level of knowledge take both the country image, where surrogate services are conducted in, and perceived risk seriously to build their attitudes and formulate decisions toward products more delicately and systematically, which is in line with previous studies. This study suggests several pieces of academic and practical advice. Precisely, country image of surrogate buying origin does affect on consumer's risk perceptions and behavioral consequences. Therefore a careful selection of surrogate buying origin is recommended. Furthermore, reducing consumers' risk level is required to blossom this new type of retail business whether its consumer are novices or experts. Additionally, since consumer take different paths of elaborating information based on their knowledge levels, sophisticated marketing approaches to each group of consumers are required. For novice buyers strong devices for risk mitigation are needed to induce them to form better attitudes and for experts selections of better and advanced countries as surrogate buying origins are advised while endorsement strategy for the site might work as a reliable information clue to all consumers to mitigate the barriers to purchase goods online. The authors have also explained that the study suffers from some limitations, including generalizability. In future studies, tests of and comparisons among different types of etailers with relevant constructs are recommended to broaden the findings.

The Legislative Directions about Surrogacy Contract on Civil law (민법상 대리모계약에 관한 입법방향)

  • Park, Jong-Ryeol
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.4
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    • pp.161-169
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    • 2013
  • Currently, there is no bill about Maternal Inference and the Family Law about surrogate birth in Korea. Also, Problems of surrogate mother were reported by media socially, but these discussions did not discuss continuously. Early in the course that establishing process of Bioethics and Safety Act, there was a discussion. But it cannot acceptance as Act, it issued legally and ethically. Despite the difficult of legal interpretation and ethical problem, the surrogate birth practiced covertly and frequently. And about this, our law just declared its invalidity because it is contrary to public order and good moral until recently. Therefore, if it leaves as invalidation, the problem about right of surrogate mother and the baby from her it may occur a serious social problem. From now, about the issue of surrogacy contracts the legal and medical countermeasures to be taken. Therefore, to solve many problems about surrogacy contract, consider the problem of surrogacy contract, also suggest legislative study about Korean surrogate mother based on legislative cases of foreign countries.

Design and Implementation of the Surrogate Transaction Manager for Mobile GIS (모바일 GIS를 위한 대리 트랜잭션 관리자의 설계 및 구현)

  • 반재훈;문선희;김동현;홍봉희
    • Journal of KIISE:Databases
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    • v.30 no.4
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    • pp.397-407
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    • 2003
  • Transactions of updating spatial dta with mobile clients are log transactions because a user disconnected from a server surveys real features and updates them. In this environment, it is appropriate to exploit the optimistic approach based on the validation test in order to control the concurrency of transactions. On the contrary, the pessimistic concurrency control scheme makes transactions wait for a long time due to the lock. In this paper, we propose the surrogate transaction model and implement its manager for the S-S-M(Server-Surrogate PC-Mobile Client) structure which is appropriate for updating spatial data in mobile environments. In the S-S-M structure, the mobile client communicates with the server by the surrogate PC. We extend the validation condition in consideration of spatial relationships between spatial objects in this model. We also present the commit protocol where the user of a surrogate PC adjusts objects of the conflicted surrogate transaction to minimize costs for the abortion of the transaction.

Design of a Condition-based Maintenance Policy Using a Surrogate Variable (대용변수를 이용한 상태기반 보전정책의 설계)

  • Kwon, Hyuck Moo;Hong, Sung Hoon;Lee, Min Koo
    • Journal of Korean Society for Quality Management
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    • v.49 no.3
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    • pp.299-312
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    • 2021
  • Purpose: We provide a condition-based maintenance policy where a surrogate variable is used for monitoring system performance. We constructed a risk function by taking into account the risk and losses accompanied with erroneous decisions. Methods: Assuming a unique degradation process for the performance variable and its specific relationship with the surrogate variable, the maintenance policy is determined. A risk function is developed on the basis of producer's and consumer's risks accompanied with each decision. With a strategic safety factor considered, the optimal threshold value for the surrogate variable is determined based on the risk function. Results: The condition-based maintenance is analyzed from the point of risk. With an assumed safety consideration, the optimal threshold value of the surrogate variable is provided for taking a maintenance action. The optimal solution cannot be obtained in a closed form. An illustrative numerical example and solution is provided with a source code of R program. Conclusion: The study can be applied to situation where a sensor signal is issued if the system performance begins to degrade gradually and reaches eventually its functional failure. The study can be extended to the case where two or more performance variables are connected to a same surrogate variable. Also estimation of the distribution parameters and risk coefficients should be further studied.

Design Optimization of Bracket for Wear Sensor of Automobile Brake Pads Based on Dynamic Kriging Surrogate Model (자동차 브레이크 패드 마모량 측정센서 브라켓의 다이나믹크리깅 대리모델 기반 설계최적화)

  • Jun-Yeong Jeong;Jung Joo Yoo;Kyung Seok Byun;Hyunkyoo Cho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.2
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    • pp.95-101
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    • 2024
  • This paper introduces an optimized design for a sensor bracket used to measure the wear amount of an automobile brake pad, based on a dynamic kriging surrogate model. During testing, the temperature of the brake pad can increase beyond 600℃, which often causes sensor malfunction. Therefore, it is essential to optimize the shape of the sensor bracket to minimize heat transfer. To reduce the computational cost of the optimization, the heat-transfer simulation is replaced by a dynamic kriging surrogate model. Dynamic kriging utilizes the best combination of correlation and basis functions and constructs an accurate surrogate model. Following optimization, the temperature of the sensor position decreases by 7.57%. The results from the surrogate model under optimum conditions are verified by a heat-transfer simulation, and the design optimization using a surrogate model is found to be effective.

Normal Development and Hatchability of Korean Oge Chickens in White Leghorn Surrogate Eggshells (화이트레그혼 대리난각 배양에 의한 오계 배아 발생)

  • Choi, Hee Jung;Kang, Kyung Soo;Lee, Hyung Chul;Lee, Hyo Gun;Rengaraj, Deivendran;Park, Tae Sub;Han, Jae Yong
    • Korean Journal of Poultry Science
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    • v.41 no.2
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    • pp.87-92
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    • 2014
  • The avian embryos have been used as a good model to study embryonic development. Due to its unique development in the eggshell, avian embryos can be cultured and hatch in the surrogate eggshell system. In this study, we examined the viability, normal development and hatchability of Korean Oge (KO) chicken embryos in White Leghorn (WL) surrogate eggshells. Donor KO embryos at 3-day and 4-day-old were transferred into recipient WL eggshells, incubated for further 18 days at $37.5^{\circ}C$ with 70% of humidity until hatching. The viability of 3-day-old KO embryos at 7, 14 and 21 day in surrogate eggshell were 70.0%, 43.8% and 23.1%, respectively. In contrast, the viability of 4-day-old KO embryos at 7, 14 and 21 day in surrogate eggshells were 87.1%, 55.6% and 36.0%, respectively. The hatchability of KO embryos transferred into surrogate eggshells at 3-day-old was 23.1%, whereas embryos transferred at 4-day-old was 36.0%. Furthermore, the development of all viable embryos from 3-day group and 4-day group were normal. Our results suggested that culture of KO embryos in WL surrogate eggshells is highly possible, and transfer of donor embryos at 4-day-old may yield higher percentage of hatchability. This study may provide potential knowledge for the conservation of wild and endangered birds through surrogate system.

Fundamental Study on the Chemical Ignition Delay Time of Diesel Surrogate Components (모사 디젤 화학반응 메커니즘의 각 성분이 화학적 점화 지연 시간에 미치는 영향에 관한 기초 연구)

  • Kim, Gyujin;Lee, Sangyul;Min, Kyoungdoug
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.3
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    • pp.74-81
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    • 2013
  • Due to its accuracy and efficiency, reduced kinetic mechanism of diesel surrogate is widely used as fuel model when applying 3-D diesel engine simulation. But for the well-developed prediction of diesel surrogate reduced kinetic mechanism, it is important to know some meaningful factors which affect to ignition delay time. Meanwhile, ignition delay time consists of two parts. One is the chemical ignition delay time related with the chemical reaction, and the other is the physical ignition delay time which is affected by physical behavior of the fuel droplet. Especially for chemical ignition delay time, chemical properties of each fuel were studied for a long time, but researches on their mixtures have not been done widely. So it is necessary to understand the chemical characteristics of their mixtures for more precise and detailed modeling of surrogate diesel oil. And it shows same ignition trend of paraffin mixture with those of single component, and shorter ignition delay at low/high initial temperature when mixing paraffin and toluene.

Economic Design of Three-Stage $\bar{X}$ Control Chart Based on both Performance and Surrogate Variables (성능변수와 대용변수를 이용한 3단계 $\bar{X}$ 관리도의 경제적 설계)

  • Kwak, Shin-Seok;Lee, Jooho
    • Journal of Korean Society for Quality Management
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    • v.44 no.4
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    • pp.751-770
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    • 2016
  • Purpose: Two-stage ${\bar{X}}$ chart is a useful tool for process control when a surrogate variable may be used together with a performance variable. This paper extends the two-stage ${\bar{X}}$ chart to a three stage version by decomposing the first stage into the preliminary stage and the main stage. Methods: The expected cost function is derived using Markov-chain approach. The optimal designs are found for numerical examples using a genetic algorithm combined with a pattern search algorithm and compared to those of the two-stage ${\bar{X}}$ chart. Sensitivity analysis is performed to see the parameter effects. Results: The proposed design outperforms the optimal design of the two-stage ${\bar{X}}$ chart in terms of the expected cost per unit time unless the correlation between the performance and surrogate variables is modest and the shift in process mean is smallish. Conclusion: Three-stage ${\bar{X}}$ chart may be a useful alternative to the two-stage ${\bar{X}}$ chart especially when the correlation between the performance and surrogate variables is relatively high and the shift in process mean is on the small side.