• Water for future
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• v.7 no.2
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• pp.92-98
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• 1974

The DAD for Nakdong River Basin is studied on the basis of qselected storms (1916~1970) by WMO Standard method. The maximum DAD BAlue for a storm period of 24hrs assuming that the basin area is estimated as about $2,500\textrm{km}^2$ comes out to be 153mm. The investigation appears to be supporting a conclusion that the Horton's formula is also applicable to this basin.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.530-533
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• 2013

본 연구에서는 음악연주 정보를 기록하는 SMF (Standard MIDI File) 대한 정보 하이딩을 스테가노그래피의 관점에서 재고 해 보았다. 그 결과 그 중 SMF 데이터 스트림에 메시지를 은닉 하는 방법이 주로 이용되어 왔다. 연주 정보 통제 방법은 포함할 수 정보량의 증대가 어렵다는 문제가 있었다. 이 보고서는 기존 방식과는 다른 성분인 듀레이션의 확률적 확산을 이용해 정보를 은닉하는 SMF 스테가노그래피를 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.9
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• pp.2402-2414
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• 1996

Registration is the process by which a base station gets the information of location and status about mobile stations. Registration will become an increasingly important issue in mobile cellular communications, especially in microcellular system with the increase of location updating traffic. Four typesof registration schemes, which are specified in US standard IS-95 and Korean standard TTA-KO-0062, power up registration scheme, power down registration scheme, distance based registration scheme and zone based registration scheme, will be mainly used in the future. In this paper, we derive the combined cost of signaling traffic of paging and registration for various parameters of mobile stations behavior(unencumbered call duration, power up and down rate, velocity, etc.) then we present numerical results for the perfroamnce of four registration schemes. The size of location area is provided for optimal operation.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.455-462
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• 2002

There exist several kinds of continuous consolidation tests to analyze the consolidation behavior of soft clay. The constant rate of strain (CRS) test has been adopted as a standard method by several countries, and some researches also have been peformed by domestic researchers. Among those, the constant pressure ratio (CPR) test is peformed with the constant ratio of excess porewater pressure to vertical effective stress. The test has the advantage of considerable reduction of duration time. In the study, the consolidation characteristics are analyzed by performing the CPR test as validate the pressure ratio with undisturbed soft clay and remolded clay, Also, results of the standard consolidation test and CRS test are compared to verify the CPR test can be employed for practical use. As a result, effects of variation of the pressure ratio on consolidation parameter are similar to the strain rate in the CRS test. Therefore, the test can be used to analyze the consolidation behavior of soft clay But the test have some problems such as expensive cost of equipment and highly skilled workmanship.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.115-122
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• 2016

Price quotations for SOR / RFQ from OEM clients is a very important process in the automotive parts industry. However, OEM clients are demanding a price quote on short duration but it takes long delivery time due to sales, research and development, purchasing, production and cost management departments role and jobs focused on detail and responsibility. And to provide a reasonable alternative with eliminating the waste of non-value processes is to achieve OEM clients satisfaction through standardized and parallel processing, IT system based on the systems and processes of global benchmark companies.

• Wind and Structures
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• v.37 no.2
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• pp.163-178
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• 2023

The paper reviews and discusses the substantive changes to the ASCE 49-21 Standard, Wind Tunnel Testing for Buildings and Other Structures. The most significant changes are the requirements for wind field simulations that utilize (i) partial turbulence simulations, (ii) partial model simulations for the flow around building Appurtenances, along with requirements for determining wind loads on products that are used at multiple sites in various configurations. These modifications tend to have the effect of easing the precise scaling requirements for flow simulations because it is not generally possible to construct accurate models for small elements placed, for example, on large buildings at the scales typically available in boundary layer wind tunnels. Additional discussion is provided on changes to the Standard with respect to measurement accuracy and data acquisition parameters, such as duration of tests, which are also related to scaling requirements. Finally, research needs with respect to aerodynamic mechanisms are proposed, with the goal of improving the understanding of the role of turbulence on separated-reattaching flows on building surfaces in order to continue to improve the wind tunnel method for determining design wind loads.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.141-148
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• 2009

The purpose of this paper is to propose a standard test methods of resistance to root penetration for waterproofing and rootproofing membrane using green roof system. Green roof system is considered to be an important subject in construction industry for green growth project. At the same time, we have to consider the counterplan for protection the damage of waterproofing layer and concrete substrate from the penetration of plant root. But many kinds of materials for protection from root penetration are using in construction field. But the performance of those materials is not clear, and there is not test methods for the evaluation of performance. So in this paper, based on the research results of 4 institutes during four years and foreign cases, we made a standard test methods of resistance to root penetration for waterproofing and rootproofing membrane using green roof system. This test method deals with about environmental condition of laboratory, experimental facilities, kinds of plant, specimen of test, management methods, evaluation duration and documents, etc.

• Journal of ILASS-Korea
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• v.16 no.3
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• pp.134-139
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• 2011

Recent research has focused on engine combustion technology as well as application of after-treatment in order to comply with emission regulation. However, it is much more efficient way to control emissions from engine itself and furthermore research on engine control will provide the direction of after-treatment technology in future. Furthermore, emission standard regulation for passenger diesel vehicles has been stringent compared to others and nano-particles will be included in EURO6 regulation in Europe and similar emission standard will be introduced in Korea. A 3.0 liter high speed diesel engine equipped with by CRDI system of 160MPa injection pressure, and an intake/exhaust system of V type 6 cylinder turbo-intercooler was applied. The injection duration and injection quantity, pilot injection types which are related to CRDI and air/fuel ratio control applied by EVGT were changed simultaneously. Standard experiment procedure constituted dilution apparatus and CPC system to collect nano-particles and these test results were compared with regulated materials of CO, HC, NOx and investigated their relations and characteristics of nano-particles.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.2
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• pp.208-221
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• 2000

The objective of this research was to compare the flushing effects using 1:1,000 diluted heparin or 0.9% normal saline in relation to needle gauge and frequency of IV medications. The comparative categories were clotting, duration of patency, and incidence of phlebitis. The design of research was a Nonequivalent Control group, Post test, Nonsynchrorized Design. The independent variable was 0.9% normal saline flushing the IV locks and the dependent variables were clotting, duration of patency, and incidence of phlebitis. Subjects were medical-surgical inpatients over 15 years old and with peripherally placed IVs who were hospitalized in a university medical center. Exclusion criteria included foreigners and those who were rejected for this research. The final sample for data analysis included 295 IV sites in 194 patients; 154 were in the saline group and 141 were in the heparin group. Subjects were assigned to have IV locks is flushed with 0.9% normal saline in the experimental group and to have IV lock flushed with 1:1,000 diluted heparin(100 units) in the control group. In order to increase reliability, the nurses who were assigned to the units involved in the study received an explanation on the standard method for locking an IV, recording method for observational data and criteria for the detection of phlebitis. Data were collected for a period of 2 weeks, from March 16, 2000 to March 29, 2000. Total duration of IV was defined the time of IV insertion to the time of discontinuation. Phlebitis was defined as the presence of the following : pain, swelling. erythema at the insertion site. Chi-square was used to determine the association between the degree of clotting, duration of patency, and incidence of phlebitis for the diluted heparin or the normal saline and needle gauge and frequency of IV medications. The results are summarized as follows : (a) There was difference in the degree of clotting between two groups($X^2=5.882$, p=.015). (b) There was no difference in the degree of duration of patency between two groups($X^2=2.439$, p=.295). (c) There was no difference in the incidence of phlebitis between two groups($X^2=0.190$, p=.663). (d) There was difference in the degree of clotting($X^2=6.209$, p=.013) and in the degree of duration of patency($X^2=6.978$, p=.031) according the needle guage between the two groups. (e) There was difference in the incidence of phlebitis($X^2=5.008$, p=.025) according to the frequencies of IV injection between two groups.

• Journal of the Korean Geosynthetics Society
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• v.21 no.2
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• pp.31-38
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• 2022

Recently, irregular torrential rainfall have frequently occurred due to abnormal climate, and landslide damage is increasing. In Korea, more than 70% of the total land is mountainous areas, appropriate measures are needed to prevent landslides by heavy rainfall. When improved soil is applied to the surface of the slope, it is possible to suppress an increase in groundwater level due to rainfall penetration and secure stability of the slope. In this study, the appropriate depth of improved soil that can confirm the increase in groundwater level and secure stability by applying improved soil to the weathered soil slope was studied. A total of three cases were analyzed for the slope of the cross-section: standard slope for weathered soil (1:1.5, 1:1.8, and 1:2.0). For rainfall conditions, referring to the regional frequency probability rainfall provided by the Water resource Management Information System, the increase in groundwater level by stage was confirmed by assuming a 500-year frequency precipitation maximum duration of 48 hours. As a result of the study, in the case of natural slopes, the slope was completely saturated before 48 hours the rainfall duration, and there was a possibility of collapse. the improvement depth in the slope of 1:1.5 was appropriate for more than 1m from the surface regardless of the rainfall duration, and in the the slope of 1:1.8 was appropriate of 1m for more than 36 hours. in the slope of 1:2.0, it was appropriate for that safety when improved soil of 0.5m for rainfall duration 48 hours or more.