• Korean Journal of Poultry Science
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• v.26 no.4
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• pp.237-245
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• 1999

This study was conducted to investigate the effect of dietary thyroid hormone (T$_3$and T$_4$) on growth, feed conversion ratio and serum T$_3$or T$_4$concentration of broiler chicks. Zero to six week-old broiler chicks were randomly allocated into seven treatment groups for feeding trials with three replication : control, T$_3$(0.1), T$_3$(1.0), T$_3$(5.0), T$_4$(0.1), T$_4$(1.0), T$_4$(5.0) ppm group. Concentrations of T$_3$and T$_4$in serum were analyzed. The weight gain of T$_3$(1.0), T$_3$(5.0) and T$_4$(5.0) groups were significantly lower than that of control. No statistically significant adverse effect was observed in other groups (p〉0.05). Feed intake was significantly lower in T$_3$(0.1, 1.0 and 5.0) and T$_4$(5.0) than in control group (p〈0.05), and the feed conversion ratio had a similar trend to the feed intake change. The contents of liquid and abdominal fat pad in carcass were significantly decreased in all T$_3$and T$_4$groups (p〈0.05). T$_3$and T$_4$concentration in serum was significantly increased at over 1.0ppm of the hormone supplementation level. As T$_3$addition level increased, T$_4$concentration in serum reduced ; however, T$_3$in serum was directly proportional during fasted were slightly increased when T$_3$or T$_4$was added to broiler diets.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.1
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• pp.25-30
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• 2006

This experiment was conducted to compare the fresh yield and dry matter yield, and nutritive values of whole crop barley treated with Urea (200 kg/ha, T2) and ammonium sulfate fertilizer as 200 kg/ha (T3), 300 kg/ha (T4) and 400 kg/ha (T5) at the Bae-Ho reclaimed tideland. Korea from 2003 to 2005. Salt contents of soil in the ammonium sulfate plots (T3, T4, T5) were lower than those of T2. The fresh yields of ammonium sulfate plots (T3, T4, T5) were higher than those of T2 as 62% (p>0.05), 41% (p>0.05) and 23% (p<0.05), respectively. The dry matter yield of T3, T4 and T5 (ammonium sulfate) was significantly (p<0.05) higher at 5,080 kg/ha, 4,667 ka/ha, 4,040 kg/ha, respectively. The total digestible nutrients (TDN) yield tends to have a similar result. Crude protein (CP) content was highest in T3 and CP trends to decrease as the level of ammonium sulfate was increased. Total digestible nutrient (TDN) were high in T3 and T4. The sodium content of T3 and T4 were lower than T2. Based on the study, it was more desirable to use ammonium sulfate (200 kg N/ha) rather than Urea as fertilizer on reclaimed land in terms of forage production and nutritive value.

• Journal of Animal Science and Technology
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• v.44 no.3
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• pp.327-340
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• 2002

This study was conducted to investigate the effects of domestic clay minerals on feed efficiency, meat quantity, meat quality and economic traits in 24 head of Hanwoo steers(166.1kg in body weight) for 540 days from six to 24 months in age. Feeding trial was conducted with 4 treatment(six heads/treatment) which were T1(Control), T2(Control+Kaolinite), T3(Control+Bentonite), T4(Control+Illite). The results obtained are summarized as follows; The range of average daily gains were 0.682 to 0.713, 0.669 to 0.714, 0.690 to 0.840 and 0.699 to 0.756kg in growing, fattening, finishing and over-all period, respectively, and the gains were high in T1 for growing and fattening period but in clay mineral groups for finishing and over-all period, especially it was high in Illite and Bentonite groups. Concentrates and TDN intakes per unit of kg gains were lower in clay mineral groups than in control and was lower especially in Bentonite groups. In carcass characteristics, dressed carcass and fresh meat and retailed cut percent were not apparently difference by treatments, and yield index was 69.3, 68.9, 68.8 and 68.6 in T3, T2, T4 and T1, respectively. Marbling scores were 5.1, 4.6, 4.4 and 3.3 in T3, T2, T4 and T1, respectively, and the range of shear force by treatment was from 3.51 to 6.02kg/cm2. and were improved with significant difference(P<0.05) in clay mineral groups than in control. Also in palatability traits, panel test scores of juiciness, tenderness and flavor were improved in clay mineral feeding groups, especially the flavor was improved with highly significant difference(P<0.01) in clay mineral groups than in control. In total fatty acid contents, the rate of SFA(saturated fatty acid) in longissimus muscle of beef was higher in the order of T2, T3, T1 and T4 while the rate of MUFA(monounsaturated fatty acid) was high in the order of T4, T3, T1 and T2. The content of oleic acid which is major influential factor at the flavor of beef was higher in Illite groups than in any other groups. In composition of amino acids in longissimus muscles of beef, the rate of essential amino acids was high in the order of T1, T2, T3 and T4. and the rate of amino acids in clay mineral groups was smaller than in control.In chemical component in Gom-Tang(soup of bone) made by Hanwoo steer’s leg-bone, the ranges of crude protein, ether extract, and crude ash was 0.81 to 1.24, 0.17 to 0.35 and 0.07 to 0.09%, respectively. In mineral composition, the ranges of Ca, P, Na and Mg was 14.01 to 15.77, 11.45 to 16.40, 37.92 to 49.99 and 0.26 to 0.46ppm, respectively. Chemical composition were not apparently different but mineral composition was increased in clay mineral groups than in control. Income by treatments was 967,096 to 1,524,055 Won per head for 540 days and income of clay mineral groups in comparison with control’s increased by 23.7 to 57.6 percent, and especially it was higher in bentonite and(or) Illite groups than others. According to the above results it may be concluded that clay mineral to growing-fattening Hanwoo steers can be improved the meat quantity, meat quality and income. Especially the effect of bentonite and illite is large and can be recommended for usage to improve animal performance as feed additives of growing-fattening Hanwoo steers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1688-1696
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• 2020

The paradigm of Internet-of-things(IoT) systems is changing from a cloud-based system to an edge-based system to solve delays caused by network congestion, server overload and security issues due to data transmission. However, edge-based IoT systems have fatal weaknesses such as lack of performance and flexibility due to various limitations. To improve performance, application-specific hardware can be implemented in the edge device, but performance cannot be improved except for specific applications due to a fixed function. This paper introduces a edge-centric metamorphic IoT(mIoT) platform that can use a variety of hardware through on-demand partial reconfiguration despite the limited hardware resources of the edge device, so we can increase the performance and flexibility of the edge device. According to the experimental results, the edge-centric mIoT platform that executes the reconfiguration algorithm at the edge was able to reduce the number of server accesses by up to 82.2% compared to previous studies in which the reconfiguration algorithm was executed on the server.

• Journal of Internet Computing and Services
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• v.24 no.1
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• pp.17-26
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• 2023

A smart city is a massive internet of things (IoT) environment, where all terminal devices are connected to a network to create and share information. In accordance with massive IoT environments, millions of IoT devices are connected, and countless data are generated in real time. However, since heterogeneous IoT devices are used, collecting the logs for each IoT device is difficult. Due to these issues, when an IoT device is invaded or is engaged in malicious behavior, such as infection with malware, it is difficult to respond quickly, and additional damage may occur due to information leakage or stopping the IoT device. To solve this problem, in this paper, we propose identifying the attack technique used for initial access to IoT devices through MITRE ATT&CK, collect the logs that can be generated from the identified attack technique, and use them to identify the cause of malware infection.

• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.343-348
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• 2023

As the IoT market continues to grow, security threats to IoT devices with limited resources are also increasing. However, the application of security technology to the existing system to IoT devices with limited resources is impossible due to the inherent characteristics of IoT devices. Various methods for solving related problems have been studied in existing studies to solve this problem. Therefore, this study analyzes the characteristics of domestic IoT authentication standards and existing research to propose an algorithm that applies blockchain-based authentication and lightweight encryption algorithms to IoT equipment with limited resources. In this study, a key generation method was applied using a Lamport hash-chain and data integrity between IoT devices were provided using a Merkle Tree, and an LEA encryption algorithm was applied using confidentiality in data communication. In the experiment, it was verified that the efficiency is high when the LEA encryption algorithm, which is a lightweight encryption algorithm, is applied to IoT devices with limited resources.

• Journal of Advanced Navigation Technology
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• v.20 no.4
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• pp.374-379
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• 2016

Recently, IoT(Internet of Things) to connect the objects and people has attracted attention. And it is rapidly developing. IoT is to develop, experts are predicting that the device is connected to the Internet to break through around 100 billion within 10 years. However, the current IoT companies are having a difficult state to the other each other IoT platform for interaction between data silos effects. These silos effects will limit the IoT grow to a larger market. Thus, the IoT service supplier shall develop an open platform for interaction IoT data between each IoT platform. These web technologies for current open IoT platform has emerged. If developers are using familiar, easy-to-learn Web technologies, developers can take advantage of a variety of services for the collected data, and found the IoT devices can be bypassed if there is a problem on the network. In this paper, we investigate the data communications technology that can be used in WoT environment to overcome these silos effects. As a result, the polling method that can simply send the IoT information the fastest.

• Journal of Digital Convergence
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• v.20 no.3
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• pp.325-331
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• 2022

As IoT devices are used in various ways in an edge network environment, multiple studies are being conducted that utilizes the information collected from IoT devices in various applications. However, it is not easy to apply accurate IoT data immediately as IoT data collected according to network environment (interference, interference, etc.) are frequently missed or error occurs. In order to minimize mistakes in IoT data collected in an edge network environment, this paper proposes a management technique that ensures the reliability of IoT data by randomly generating signature values of IoT data and allocating only Security Information (SI) values to IoT data in bit form. The proposed technique binds IoT data into a blockchain by applying multiple hash chains to asymmetrically link and process data collected from IoT devices. In this case, the blockchainized IoT data uses a probability function to which a weight is applied according to a correlation index based on deep learning. In addition, the proposed technique can expand and operate grouped IoT data into an n-layer structure to lower the integrity and processing cost of IoT data.

• Journal of Information Technology Services
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• v.18 no.4
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• pp.97-113
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• 2019

With the development of sensor, communication and intelligent software technology, expectation of IoT-based service which can receive desired service automatically and anytime, anywhere is getting higher. In addition, IoT-based services have begun to anticipate the development of a hyper-connected society. Despite these expectations and anticipations, few studies have empirically identified ways to improve the intentions of prospective customers to use IoT-based services. Therefore, the purpose of this paper is to propose a theoretical model that can explain the factors that determine the intention of using IoT-based services. In addition, this study investigates what factors affect the intention to use IoT-based services focusing on the connectedness. Especially, perceived connectivity with the (virtual) community, unlike the connectivity with the machines, is newly proposed, to understand the IoT technology adoption behavior. The empirical results suggest that social relationship is one of the critical factors to affect the use of services running on interconnected technology such as IoT. When IoT-based service is recognized as a link to other communities, it has been found to have a positive effect on intention to use via perceived belongingness.

• Advanced Industrial SCIence
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• v.3 no.1
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• pp.30-36
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• 2024

Recently, the Internet of Things (IoT), which has been applied to various industrial fields, is constantly evolving in the process of automation and digitization. However, in the network where IoT devices are built, research on IoT critical information-related data sharing, personal information protection, and data integrity among intermediate nodes is still being actively studied. In this study, we propose a blockchain-based IoT critical information management technique that is easy to implement without burdening the intermediate node in the network environment where IoT is built. The proposed technique allocates a random value of a random size to the IoT critical information arriving at the intermediate node and manages it to become a decentralized P2P blockchain. In addition, the proposed technique makes it easier to manage IoT critical data by creating licenses such as time limit and device limitation according to the weight condition of IoT critical information. Performance evaluation and proposed techniques have improved delay time and processing time by 7.6% and 10.1% on average compared to existing techniques.