• IE interfaces
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• v.12 no.2
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• pp.346-353
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• 1999

In this paper, the optimum drilling operation sequence which results into the minimum overall machining time required to produce a (multi-diameter) hole is identified. The operation sequence is defined as the set of ordered operations used for producing a (multi-diameter) hole. The overall machining time is derived by summing the minimum machining times of each operation assigned to a sequence. The operations represent the drilling actions of certain sizes to produce the related holes. The minimum machining time of each operation is obtained by solving the optimization problem. Finally, this paper will identify the effects of machining constraints on the overall machining times and their relationships to sequence selection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12C
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• pp.1044-1051
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• 2010

In this paper, we propose an efficient soft-output signal detection method for spatially multiplexed multiple input multiple output (MIMO) systems. The proposed method is based on the ordered successive interference cancellation (OSIC) algorithm, but it significantly improves the performance of the original OSIC algorithm by solving the error propagation problem. The proposed method combines this enhanced OSIC (ESIC) algorithm with a multiple ordering technique in a very efficient way. As a result, the log likelihood ratio (LLR) values can be computed by using a very small set of candidate symbol vectors. The proposed method has been implemented with a $0.13{\mu}m$ CMOS technology for a $4{\times}4$ 16-QAM MIMO system. The simulation and implementation results show that the proposed detector provides a very good solution in terms of performance and hardware complexity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4328-4336
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• 2011

The aim of this study is to find changes of the attributes that influence the purchase of cut roses during recent five years(2007~2011) and suggest some implications on ways to promote cut roses marketing. For this purpose, a survey was conducted through the Internet among 1,100 randomly chosen people living in Seoul, Inchon and Gyeonggi Province in 2011. A total of 1,023 valid replies were received for the analysis of the survey which was carried out by the subsidiary consulting firm. The survey panels and estimation models to analyze changes of consumers' preference attributes during recent five years are same to them of Kim, et al.(2007). That is, empirical analysis tools such as ordered probit model, multinomial logit model, and conjoint analysis were used according to Kim, et al.(2007). This paper suggests several policy implications to set up the target market of cut roses and marketing mix strategy to specify the best 4P(product, price, place and promotion).

• Journal of the Korean Dietetic Association
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• v.7 no.3
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• pp.217-226
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• 2001

It is important to supply adequate nutrition to critically ill patients, whose gastrointestinal system is properly functioning, through the enteral tube feeding if oral intake is impossible. In this study we investigated the changes in nutritional status with enteral tube feeding according to the volume required. We investigated the volume ordered according to the patient's requirements, volume infused according to the volume ordered in 41 enteral tube feeding patients in intensive care unit from Jannuary to July, 2000. Body weight, serum albumin level, and total lymphocyte count were evaluated to assess nutritional status. The mean fasting period was 5 days before the enteral feeding and patients whose fasting period over 3 days were 51%. The mean enteral tube feeding period was 29 days and method of feeding was nasogastric, bolus feeding 6 times per day. The volume ordered was 69.7% of the patients' recommended calorie and volume infused was 86.6% of their volume prescribed. Accordingly, the volume infused was estimated 61.7% of their volume required. Only 44.6% of their reqiured volume was infused within 3 days after enteral tube feeding was started. It took 16 days in average to meet the patients' recommended calorie; 56% of subjects still did not fully met their requirements by the end point. Among the impeding factors in supplying enteral tube feeding, factors related to the number of feeding were high residual volume in stomach, vomiting, gastrointestinal bleeding, abdominal distension and surgery. Factors related to the acctual infused volume were diarrhea, gastrointestinal bleeding, abdominal distension, airway management and tube reinsertion. Significant correlations were shown between the volume infused and changes in both the patients' weight and serum albumin level. Deviding the subjects into two groups by their infused volume, less than 70% and more than that, we compared the two to come up with a significant difference in their serum albumin level, -0.23 vs 0.21, and their body weight, -4.52 vs 0.12. In enteral tube feeding, the volume delivered in sufficient to the pateints' energy requirement can affect their nutriitional status in critically ill patient; adequate nutritional management plan is essential. It is necessary to make every effort to educate clinical staff and to set up a unified management program to prescribe adequate ammount of energy for the patient's nutritional requirement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.10
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• pp.841-849
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• 2012

This paper proposes an low-complexity soft-output multiple-input multiple-output (soft-MIMO) detection algorithm for achieving soft-output maximum-likelihood (soft-ML) performance under max-log approximation. The proposed algorithm is based on a parallel tree-search (PTS) applying a channel ordering by a sorted-QR decomposition (SQRD) with altered sort order. The empty-set problem that can occur in calculation of log-likelihood ratio (LLR) for each bit is solved by inserting additional nodes at each search level. Since only the closest node is inserted among nodes with opposite bit value to a selected node, the proposed node insertion scheme is very efficient in the perspective of computational complexity. The computational complexity of the proposed algorithm is approximately 37-74% of that of existing algorithms, and from simulation results for a $4{\times}4$ system, the proposed algorithm shows a performance degradation of less than 0.1dB.

• Journal of the Korean Society for Library and Information Science
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• v.30 no.2
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• pp.149-165
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• 1996

Hong-sii Tokso-rok (홍씨독서록 or Hong's Annotated Bibliography of Korean and Chinise Book) is the only work on the history of Korean bibliographies that has the introductory notes to each class, that is description of the origin of subject fields, transition, and characteristics at the beginning of each class. This paper is aimed to examine the outline of the introductory description of class, to analyze the Four Category Classification System(사부분류법) devised by Hong Sok-chu, and to explain how the classes of Four Category Classification are set and ordered. This paper shows several characteristics in the idea of Hong's classification system. There characteristics were discovered by analyzing the content of each introduction of classes. The characteristics ale as follows First, classes are organize and arranged from the substantial problem to nonsubstantial ones. In other words, the greater the distance of the class from the substantial problem of Confucianism, the farther the order of the class will be found from the substantial problem. The order of classes is set by how the class is closed to the substantial problem in the same hierarchy. This principle is strictly applied to the Hong's classification system. Second, on the basis of democratic thought, he del·eloped the classification system. In other words, when he set up the priority of classes, he put emphasis on the democratism as a guideline. The organization of classes belong to the catagories of history (Sa-bu, 사부) and philosophy(Cha-bu, 자부) showed the application of this principle. Conclusively, this paper found that Hong did not randomly arrange the class older, but he set the class order with objective reasons and logic when he set the class order of arrangement.

• Journal of Information Processing Systems
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• v.9 no.4
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• pp.511-537
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• 2013

Numerous data intensive applications demand the efficient processing of a new type of query, which is called a progressive query (PQ). A PQ consists of a set of unpredictable but inter-related step-queries (SQ) that are specified by its user in a sequence of steps. A conventional DBMS was not designed to efficiently process such PQs. In our earlier work, we introduced a materialized view based approach for efficiently processing PQs, where the focus was on selecting promising views for materialization. The problem of how to efficiently find usable views from the materialized set in order to answer the SQs for a PQ remains open. In this paper, we present a new index technique, called the Dynamic Materialized View Index (DMVI), to rapidly discover usable views for answering a given SQ. The structure of the proposed index is a special ordered tree where the SQ domain tables are used as search keys and some bitmaps are kept at the leaf nodes for refined filtering. A two-level priority rule is adopted to order domain tables in the tree, which facilitates the efficient maintenance of the tree by taking into account the dynamic characteristics of various types of materialized views for PQs. The bitmap encoding methods and the strategies/algorithms to construct, search, and maintain the DMVI are suggested. The extensive experimental results demonstrate that our index technique is quite promising in improving the performance of the materialized view based query processing approach for PQs.

• Journal of Digital Convergence
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• v.12 no.3
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• pp.317-323
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• 2014

This research has a purpose of providing base data to prevent musculoskeletal disorders, by analyzing the changes in muscle body due to sling exercises, of the industrial laborers with work-related musculoskeletal disorders. The subjects of this research are 20 volunteers who applied for musculoskeletal treatment exercises in hospitals, from region D industry H. 10 of the 20 subjects were involved in sling exercise program for 12 weeks, and the other 10 subjects were ordered to retain their common practices. We have used the statistics software SPSS ver.18.0 to analyze the data, and have offered a descriptive analysis of the measured variables. To discover the sling exercise effects, we have executed a t-test (paired sample t-test) comparing the before-after relationship of 12-week sling exercise program, and the level of significance were set to a=.05. With these set of research methods and procedures, we have concluded the following. As a result, we have concluded that 12-week sling exercise program does exert influence in changing muscle body of work-related musculoskeletal patients.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.222.2-222.2
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• 2015

A $Ge_2Sb_2Te_5$ nanowire (GST NW) phase change memory device is investigated with Joule heating electrodes. GST is the most promising phase change materials, thus has been studied for decades but atomic structure transition in the phase-change area of single crystalline phase-change material has not been clearly investigated. We fabricated a phase change memory (PCM) device consisting of GST NWs connected with WN electrodes. The GST NW has switching performance with the reset/set resistance ratio above $10^3$. We directly observed the changes in atomic structure between the ordered hexagonal close packed (HCP) structure and disordered amorphous phase of a reset-stop GST NW with cross-sectional STEM analysis. Amorphous areas are detected at the center of NW and side areas adjacent to heating electrodes. Direct imaging of phase change area verified the atomic structure transition from the migration and disordering of Ge and Sb atoms. Even with the repeated phase transitions, periodic arrangement of Te atoms is not significantly changed, thus acting as a template for recrystallization. This result provides a novel understanding on the phase-change mechanism in single crystalline phase-change materials.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.4
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• pp.605-610
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• 2013

A cryptography for enforcing hierarchic groups in a system where hierarchy is represented by a partially ordered set was introduced by Akl et al. But the key generation algorithm of Akl et al. is infeasible when there is a large number of users. To overcome this shortage, in 1985, MacKinnon et al. proposed a paper containing a condition which prevents cooperative attacks and optimizes the assignment. In 2005, Kim et al. proposed the key management systems for using one-way hash function, RSA algorithm, poset dimension and Clifford semigroup in the context of modern cryptography, the key management system using Clifford semigroup of imaginary quadratic non-maximal orders. We, in this paper, show that Kim et al. cryptosystem is insecure in some reasons and propose a revised cryptosystem.