• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1595-1602
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• 2010

A disposable drug infuser is used to provide drugs to patients who are not hospitalized; in this infuser, an elastic recovery force is exerted by a diaphragm made of a rubber-like materialsuch that a constant amount of drugs is provided to a patient. The drug infuser has to control the speed and amount of drugs to be released, as well as the overall duration for which they are to be administered. However, in a drug infuser with an elastic diaphragm, the infusion pressure depends on the amount of drug remaining within the infuser, and the amount of drug infused gradually decreases as the amount remaining in the infuser decreases. In this study, a finite element procedure involving the application of the fluid-structure interaction technique was developed and the performance of the elastic type disposable drug infuser was analyzed. The optimum design for ensuring that the infusion pressure remains constant throughout the duration of usage, including during infusion and discharge, was determined by this procedure.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.8
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• pp.1175-1185
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• 2004

This study evaluated thermo-physiological and subjective properties of improved disposable coveralls for railroad carriage maintenance through climatic chamber trials and a filed study. Subjects wore five kinds of disposable coveralls (Type A: a disposable coverall on the market, Type B: a coverall with an improved hood and size-adjustable design, Type C: a coverall with a portable hood, Type D: a coverall with small holes for ventilation, Type E: a sleeveless coverall, Type F: a separated type of coverall with half sleeves) The air temperature in the climatic chamber was set in 9$^{\circ}C$ and 30$^{\circ}C$ For each condition, subjects simulated the railroad work for 120min. and rectal temperature, skin temperatures, clothing microclimate and subjective sensations were measured. The results of chamber trials showed rectal temperature and clothing microclimate did not display significant differences by clothing type. In 30$^{\circ}C$ air temperature, mean skin temperature was higher in Type E and Type F than in Type A(p＜0.05) but between the improved coveralls(B-F), we could not find any significant difference. In the case of thermal comfort, the most preferred types were Type B and Type C in 9$^{\circ}C$ and Type F in 30$^{\circ}C$. All subjects felt more comfortable in the improved coveralls than in coveralls of the market (Type A). In field study, workers preferred Type B, Type C and Type F to Type A but the most favorite type differed by the specific type of work. Especially, workers were dissatisfied that Type D tore easily due to lots of small holes around the armpits and Type I did not protect workers＇ shoulder and arms from oil contamination. According to the climatic chamber trials and field study, the most effective coveralls were Type B and Type C for winter and Type F for summer.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.8
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• pp.1117-1129
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• 2013

The sizing system for Korean Standard of Disposable Protective Coveralls (DPC) uses the ISO sizing system without modification even though the user suitability for Koreans is unverified. This study provides useful information to improve the size standard of Korean DPC by analyzing measurement DPC data from Korean men and women. The distribution of Korean measurements shows that the size sections were unsuitable for Korean men and women for a protective clothing size standard. Body types were categorized into five types based on a cluster analysis of representative men's and women's measurement factors. Two clusters mostly consisted of men, two other clusters mostly consisted of women, and the other cluster relatively evenly consisted of men and women. Therefore, characteristic body measurements and measurement distribution differences were identifiable for men and women. In conclusion, an unmodified ISO protective clothing size standard is unsuitable for Korean men and women and may cause fit problems. This study shows that a Korean Standard of protective clothing is beneficial for protective clothing manufacturers and wearers if smaller size intervals are added for women and the difference in the distribution of men and women is reflected in the current sizing system. ISO is appropriate to use a Korean Standard in this global era, however, it should be reviewed to provide improved Korean data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.661-669
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• 2008

Nowadays, authentication is essential to identify the legal users in a network communication. Usually, there are few wars to achieve authentication over a publicly accessible network system in order to protect certain private data from the unauthorized users, ranging from simple ID/Password to Biometrics System. One of the most active areas in OTP(One Time Password) research today aims at exploiting OTP to provide authentication in the finance and security industry. OTP is usually discarded once it has been used. this prevents huge loophole of traditional authentication system which employs the same ID and Password every time. However this OTP system also has its weaknesses in surviving some attacks. this paper proposes an advanced OTP protocol using PingPong-128 without loop hole of pre-existing OTP.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.229-236
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• 2008

In this paper, re proposed scheme that it safely exchange encrypted keys without Trust Third Party(TTP) and Pre-distributing keys in ubiquitous environments. Existing paper assume that exist a TTP or already pre-distributed encrypted keys between nodes. However, there methods are not sufficient for wireless environments without infrastructure. Some existing paper try to use the Diffie-Hellman algorithm for the problem, but it is vulnerable to Replay and Man-in-the middle attack from the malicious nodes. Therefore, Authentication problem between nodes is solved by modified the Diffie-Hellman algorithm using ${\mu}TESLA$. We propose safe, lightweight, and robust pair-wise agreement algorithm adding. One Time Password(OTP) using timestamp to modified the Diffie-Hellman in ubiquitous environments, and verify a safety about proposed algorithm.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.700-705
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• 2021

A portable and disposable pH sensor based on Ti wire was successfully developed for monitoring hydronium ion concentrations. A sensing electrode was prepared by electrochemically depositing iridium oxide onto a Ti wire, while a reference electrode was fabricated by coating Ag/AgCl ink on a Ti wire. Combining the two electrodes in the pH sensor enabled the collection of open circuit potential signals when the sensor was immersed in solutions of various pH values. The pH sensor exhibited excellent electrochemical sensing performance in terms of sensitivity, response time, repeatability, selectivity, and stability. To demonstrate point-of-measurement applications, the pH sensor was integrated with a wireless electronic module that could communicate with a mobile application. The portable pH sensor accurately measured pH changes in real samples. The results obtained were consistent with those of using a commercial pH meter.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.33-38
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• 2019

In this paper, we propose a new blockchain technology that could comply with GDPR. The proposed model can prevent illegal access by controlling access to the personal information according to a access policy. For example, it can control access to the information on a role-basis and information validation period. The core mechanism of the proposed model is to encrypt the personal information with public key which is associated with users attributes policy, and then decrypt it with a private key and users attributes based on a Attribute-based Encryption scheme. It can reduce a trusted third-part risk by replacing it with a number of nodes selected from the blockchain. And also the private key is generated in the form of one-time token to improve key management efficiency. We proved the feasibility by simulating the proposed model using the chaincode of the Hyperledger Fabric and evaluate the security.

• Journal of the Korea Society of Computer and Information
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• v.14 no.6
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• pp.27-32
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• 2009

Recently, most of information services are provided by the computer network, since the technology of computer communication is developing rapidly, and the worth of information over the network is also increasing with expensive cost. But various attacks to quietly intercept the informations is invoked with the technology of communication developed, and then most of the financial agency currently have used OTP, which is generated by a token at a number whenever a user authenticates to a server, rather than general static password for some services. A 2-Factor OTP generating method using the OTP token is mostly used by the financial agency. However, the method is vulnerable to real attacks and therefore the OTP token could be robbed and disappeared. In this paper, we propose a 3-Factor OTP way using HMAC to conquer the problems and analyze the security of the proposed scheme.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.128-136
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• 2005

Purpose : Urine collection using a sterile adhesive bag for urinalysis has been used commonly in infants and young children. However, this method has had some drawbacks. So, this study was performed to evaluate the usage of disposable diapers as a substitute for the routine urine collection method. Methods : 60 mL of self voided fresh urine was collected from 99 patients. Half of the urine was poured on the disposable diapers which did not contain absorbent gel beads. After 1 hr, we obtained the urine samples(extracted urine) by compressing the wet diapers using a 50 ml syringe. Routine, microscopic and biochemical analyses were performed on the other half of fresh urine and extracted urine. Then we compared each result by correlative analysis. Results : 198 samples from 99 patients were evaluated. The results of routine urinalysis except WBC and biochemical urinalysis showed a significant correlation between the two groups(P<0.05). The relative coefficients of urine SG, pH, glucose, protein, blood and leukocytes between the two groups were 0.964, 0.938, 0.977, 0.956, 0.931 and 0.738, respectively. Those of urinary sodium, potassium, chloride and creatinine were 0.997, 0.998, 0.995 and 0.998, respectively Microscopic examinations showed lower relative coefficients than the other results, 0.740 for RBC and 0.602 for WBC, but these were still significant(P<0.05). Conclusion : The results of the urine analysis with extracted urine from diapers correlates well with that of fresh urine. This new method is very helpful and can be used as an alternative of urine collection, especially for infants and young children. (J Korean Soc Pediatr Nephrol 2005;9:128-136)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.700-707
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• 2000

In this paper, we address vulnerabilities of legacy VOD system and implement secure-VOD system to protect security holes of it. Our secure-VOD system provide user authentication using one-time password, message authentication and encryption/decryption for video server information. To improve security of existing fixed password system, our secure-VOD system use one-time password. Also, our secure-VOD system provides integrity for video server information by generating and verifying message authentication code using HMAC-HAS 160 algorithm. Finally, our secure-VOD system uses RC5 encryption algorithm to guarantee confidentiality for video server information.