• Bulletin of the Korean Mathematical Society
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• v.60 no.1
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• pp.149-160
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• 2023

Let 𝖆 and 𝖇 be ideals of a commutative Noetherian ring R and M a finitely generated R-module of finite dimension d > 0. In this paper, we obtain some results about the annihilators and attached primes of top local cohomology and top formal local cohomology modules. In particular, we determine Ann(𝖇 H^d_𝖆(M)), Att(𝖇 H^d_𝖆(M)), Ann(𝖇𝔉^d_𝖆(M)) and Att(𝖇𝔉^d_𝖆(M)).

• Journal of Energy Engineering
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• v.25 no.1
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• pp.56-68
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• 2016

Extensive researches have been carried out for enhancing the safety of nuclear power plants and, especially, the development of passive cooling systems, such as passive containment cooling system (PCCS) and passive residual heat removal system, is increasingly important, where condensation is a crucial heat transfer mechanism. Recently, Ahn & Yun et al. developed a horizontal in-tube condensation heat transfer model as one of the activities for the PCCS development. In this work, we implemented the Ahn & Yun 's condensation heat transfer model into the MARS code and assessed it using the PASCAL experimental data. Based on the results of the assessment, we identified the limitations of the Ahn & Yun 's model and suggested a modified Ahn & Yun 's model, and assessed the model using various experimental data.

• Child Health Nursing Research
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• v.5 no.2
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• pp.136-150
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• 1999

The subjects, under 18 old, 2,694 children who visited ER during 1998, were surveyed by the Triage and other statitical data. The results were as follows 1. The male to female ratio was 1.7 : 1, and the toddler(1-4 old) was the majority. 2. Triage ; critical 1.3%, acute 14.6%, urgent 29.5%, nonemergent 54.6%. 3. The reasons of visiting ER ; 1) The children had diseases(46.5%), injury (36.9%), TA(5.6%) and toxication(1.0%). 2) In diseases, male to female ratio was 1.5 : 1 and in injury, male to female was 2 : 1. 3) Among the children having in TA, 12-18 old groups was the majority(34.9%). 4. The time of visiting : the 20:00 - 22:00 was the majority(16.9%). 5. By monthly and seasonal distribution ; Jan. (9.7%), Mar. and May(9% respectively, Dec. and July(6.7%) respectively. The children who visted ER in spring and autumn showed higher portion than those of summer and winter. 6. Results ; admission(27.4%), discharge(68.4%), operations(2.8%), and DOA and DAA(0.4%), The mortality of the infancy and toddler groups was 83.3%. The infancy group showed the highest rate of admission. 7. The time of staying in ER ; 1-2 hrs was the major group(23.3%) and the average was 4.6 hours. 8. By clinical departments ; Ped. was 34.4%, PS was 20.8%, Dental Surgery was 10.3% and Dermatology was 0.9%. 9. The types of visting ; the group who visited by themselves was 80%, transfer from the primary and secondary clinic was 17% and OPD was 3.0%. 10. The traffic means . by the own cars and taxi were 87.6%, by hospital ambulance was 6.1% and by 119 ambulance was 4.3%.

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.231-243
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• 2018

This study was conducted to determine and compare the perceived number of users (PNU) and evaluative standards for each type of visitors to "Healing Field" of Jangseong Pyunbaek Healing Forest (JPHF). Data were collected from 158 samples selected by convenient sampling method from the users of "Healing Field" in JPHF during September 2017. Visitors to "Healing Field" consisted of 49.3% for recreation (VR), 15.3% for healing (VH), and 35.3% for both recreation and healing (VRH). Respondents' average PNU was 23.8 (median: 20.0), and the range of average PNU by visitor type was 21.1-27.8 (median: 20.0). Respondents' PNU showed low correlations with perceived crowding (PC) (r=0.23) and perceived interference of healing experience (PIHE) (r=0.20). There were no differences in the optimal number of users (ONU) of "Healing Field" among the types of visitors. The overall average ONU was 28.9(median: 25.0), and the range of average ONU by types of visitors was 25.4-31.4 (median: 25.0-27.5). The overall maximum acceptable number of users (MANU) was 38.1, and MANU for VR, VH, and VRH was 36.9, 32.0, and 38.0, respectively. Respondents' mean PC was 2.73 (SD: 3.26, 9-point scale) while mean PIHE was 3.26 (SD: 1.77, 9-point scale). The VRH group showed a higher PC and PIHE than the VR group. The group with greater PNU than ONU showed higher PC and PIHE than the other groups. Based on the results, this paper presented some managerial implications, discussed the limitations of the study, and suggested the further studies.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.491-494
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• 2002

The real-time industrial network often referred to as fieldbus, is an important element for building automated manufacturing systems. Thus, in order to satisfy the real-time requirements of field devices such as sensors, actuators, and controllers. numerous standard organizations and vendors have developed various fieldbus protocols such as Profibus, WorldFIP and Foundation Fieldbus. However, the application of fieldbus has been limited due to the high cost of hardware and the difficulty in interfacing with multi-vendor products. In order to solve these problems, the computer network technology, especially Ethernet (IEEE 802.3), is being adopted lo the industrial environment. The crucial technical obstacle for Ethernet is that its non-deterministic behavior makes it inadequate for industrial applications where real-time data such as control command and alarm signal hale to be delivered within a certain time limit. Recently, the development of switched Ethernet shows a very promising prospect for industrial application due to the elimination of uncertainties in the network operation resulting in much improved performance. This paper focuses on the application of the switched Ethernet for industrial comm unications.

• Macromolecular Research
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• v.15 no.1
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• pp.65-73
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• 2007

Chitosan, fibroin, and hydroxyapatite are natural biopolymers and bioceramics that are biocompatible, biodegradable, and resorb able for biomedical applications. The highly porous, chitosan-based, bioceramic hybrid composite, chitosanlfibroin-hydroxyapatite composite, was prepared by a novel method using thermally induced phase separation. The composite had a porosity of more than 94% and exhibited two continuous and different morphologies: an irregularly isotropic pore structure on the surface and a regularly anisotropic multilayered structure in the interior. In addition, the composite was composed of an interconnected open pore structure with a pore size below a few hundred microns. The chemical composition, pore morphology, microstructure, fluid absorptivity, protein permeability, and mechanical strength were investigated according to the composition rate of bioceramics to biopolymers for use in tissue engineering. The incorporation of hydroxyapatite improved the fluid absorptivity, protein permeability, and tenacity of the composite while maintaining high porosity and a suitable microstructure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.465-468
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• 2000

The procedure of semi-solid forming is composed of heating a billet, forming, compression holding and ejecting step. There are several methods to heat a billet during semi-solid forming process such as electric heating and induction heating. Usually in semi-solid forming process, induction heating has been adopted to achieve more uniform temperature of semi-solid material. Although induction heating is better method than any others, however, there is still difference of temperature between internal part and surface part of semi-solid material. Worse yet, in case of high liquid fraction of semi-solid material, liquid of the billet will flow down though solid of the billet still remains, which is very difficult to handle. In the present study, induction heating of semi-solid material with compulsive surface cooling has been performed to obtain uniform distribution of temperature. Distribution of temperature of the billets was measured and compared with that of conventional distribution of temperature. By this new induction heating method, not only temperature over the whole billet become uniform, but also control of temperature is possible.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.123-124
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• 2006

Usually, hydraulic cylinder is widely used as the actuator in the equipment of construction machines, airplane and military machines. In case of these devices, due to use under severe environment such as water, $SiO^2$ and dust, etc. seal which has high packing ability and long service life has been required. These characteristics are largely influenced by material and geometries of seal such as approach angle, withdrawal angle and interference. Recently, many a study about seal material has been performed so that many materials have been developed. But the concrete studies including the relationships between geometry of seal and sealing performance have hardly been performed yet. Therefore, in this study, we predicted the deformation behavior and contact normal distribution of dust seal with the variation of geometries of seal lip using finite element analysis. And based on the results of analyses, we discussed the effects of the design variables fur sealing performance of the dust seal.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.511-514
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• 2002

In may automated systems such as manufacturing systems and process plants, an industrial network or fieldbus is a very important component for the exchange of various and sometimes crucial information. Some of the information has a tendency to rapidly lose its value as time elapses after its creation. Such information or data is called real-time data that includes sensor values and control commands. In order to deliver these data in time, the fieldbus network should be tailored to have short delay with respect to the individual time limit of various data. Fine-tuning the network for a given traffic requires the knowledge on the relationship between the protocol parameters such as timer values and the performance measure such as network delay. This paper presents a mathematical performance model to calculate communication delays of the Profibus FMS network when the timer value TTR and the traffic characteristics are given. The results of this model is compared to those from experiments to assess the model's validity.

• Atmosphere
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• v.22 no.4
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• pp.455-464
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• 2012

This study investigates a 12 month-lead predictability of PNU Coupled General Circulation Model (CGCM) V1.1 hindcast, for which an oceanic data assimilated initialization is used to generate ocean initial condition. The CGCM, a participant model of APEC Climate Center (APCC) long-lead multi-model ensemble system, has been initialized at each and every month and performed 12-month-lead hindcast for each month during 1980 to 2011. The 12-month-lead hindcast consisted of 2-5 ensembles and this study verified the ensemble averaged hindcast. As for the sea-surface temperature concerns, it remained high level of confidence especially over the tropical Pacific and the mid-latitude central Pacific with slight declining of temporal correlation coefficients (TCC) as lead month increased. The CGCM revealed trustworthy ENSO prediction skills in most of hindcasts, in particular. For atmospheric variables, like air temperature, precipitation, and geopotential height at 500hPa, reliable prediction results have been shown during entire lead time in most of domain, particularly over the equatorial region. Though the TCCs of hindcasted precipitation are lower than other variables, a skillful precipitation forecasts is also shown over highly variable regions such as ITCZ. This study also revealed that there are seasonal and regional dependencies on predictability for each variable and lead.