• Journal of the Korean Home Economics Association
• /
• v.40 no.6
• /
• pp.39-51
• /
• 2002

Pregnancies of unmarried women are one of the most serious sex problems because they can negatively affect the lives and development of both unwed mothers and their extramarital children. The number of unwed adolescent mothers is growing recently, extending the seriousness of the problem. This study was conducted to explore the ego-state, life position and family systems that may cause unmarried pregnancy. The data obtained from the structured questionnaire survey of 79 unmarried adolescent mothers and 82 female adolescents were analyzed in terms of frequency and t-test using the SPSS WIN 8.0 program. The results were as follows: 1. Ego-state elements of unmarried adolescent mothers were distributed evenly in general and this falls under the All B(BBBBB) type of ego-gram, just like the adolescents. As for the subject adolescent mothers, CP was the lowest among the 5 egos. 2. As to the life position, the position of "I′m OK, You′re OK"was the highest for both groups, with slight differences. 3. With regard to the family system types sorted by the combination of family cohesion and family adaptability levels, both the adolescent. mothers and adolescents tended to perceive their families as somewhat-balanced or balanced families. 4. While the two groups of adolescent mothers and adolescents showed, on the whole, the same types for all the indicators like above, statistically significant differences were found in more detailed elements.

• Journal of Construction Engineering and Project Management
• /
• v.4 no.3
• /
• pp.1-12
• /
• 2014

Construction management has been suffering from many problems, which need to be solved or better understood. Most of construction projects have not achieved efficiency as expected. In this context, waste was also considered as a problem of efficiency decrease, and poor production planning was considered as a cause for waste. This study was conducted on the basis of waste concepts and production planning processes based on the philosophies of Lean Construction. A survey to find out the relationship between them was carried out through questionnaire, which was answered by experienced people in construction projects. The results have shown that frequency of wastes occurrence is quite high, and production planning processes are superficially performed in construction phase. There is a significant negative relationship between production planning and waste occurrence (r = -0.262). Weekly Work Plan (WWP) is the most dominant plan for waste control with seventeen in total of nineteen waste factors, and phase plan is the most dominant plan for two remaining waste factors. A case study was adopted to validate the relationship between production planning and waste occurrence. The results showed that the better the project was planned, the fewer the waste would occur on construction sites.

• Journal of Construction Engineering and Project Management
• /
• v.4 no.3
• /
• pp.33-46
• /
• 2014

Delay is the most common problem in the construction industry. It has many negative effects on project's success in terms of time, cost, quality, and safety. From the literature review, a total of thirty-five factors of delay were selected. These factors were divided into seven groups related to materials, manpower, owner, consultant, contractor, construction, and external problems. This study was carried out to identify the main causes of delay for a construction project through their importance level. The importance level was determined based on the frequency of occurrence and severity of impact. The structured questionnaire has distributed to the respondents who have much experience in construction management in Bangladesh. The results of analysis indicated that top five factors of construction delay according to their level of importance are: (1) price of construction materials increased very rapidly, (2) political situation (revolution/ public strikes), (3) shortages of skilled workers, (4) poor site management and supervision by contractor, (5) incompetent/ immature subcontractors. These findings of this study are expected to be significant contributions to Bangladesh construction industry in controlling current performance of project on time overrun.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.34D no.5
• /
• pp.1-6
• /
• 1997

An analysis method for the electromagnetic scattering of a tE polarized plane wave from a periodic strip grating over a grounded dielectric slab is consisered from the viewpoint of reflectio ngraing problem. The strip gratings showing bragg and off-bragg balzing phenomena at the frequency of 10GHz are designed, respectively. The strip grating structure is implemented using aluminum plate (hround conductor), paraffin(dielectric material ; .xi.$_{\gamma}$=2.24) and copper (strip conductor ; 0.08mm thickness). The experimental results (reflection power) for bragg as well as off-bragg blazing phenomenon have been compared with the theoretical results and fairly good agreements between theory and experiment have been observed.ed.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2006.05a
• /
• pp.203-207
• /
• 2006

This paper deals with a problem of detecting BCC using confocal raman spectrum. Specially, we propose Fisher measure based filtering for rejection of frequency components being noisy or non-discriminative. we use PCA (principal component analysis) for reduction of feature space dimension. Also, we apply MAP detector for classification of BCC raman spectrum. The experimental results shows that our proposed method can reduce the feature dimension and also raise the detection ratio.

• 한국정보통신설비학회:학술대회논문집
• /
• 2009.08a
• /
• pp.54-58
• /
• 2009

In this paper, the ECT(eddy current testing) signal analysis of eddy current array probe for inspection of SG(steam generator) tube in NPP(nuclear power plant) using electromagnetic FEM(finite element method) was performed. To obtain the electromagnetic characteristics of probes, the governing equation was derived from Maxwell's equation, and the problem was solved by using the 3-dimensional FEM. The types of defects were FBH(flat bottomed hole) and OD groove, Spiral groove, natural defects(pitting, SCC, multiple SCC, wear). The depth of FBH defects were 20%, 40%, 60%, 80%, 100 of SG tube thickness, and it was assumed that the defects were located on the tube outside. And the operation frequency of 100kHz, 300kHz and 400kHz were used. Material of specimen was Inconel 600 which is usually used for SG tubes in NPP. The signal difference could be observed according to the variation of size and depth on FBH defects and operation frequencies. The results in this paper can be helpful when the ECT signals from EC array probe are evaluated and analyzed.

• 한국정보통신설비학회:학술대회논문집
• /
• 2009.08a
• /
• pp.275-280
• /
• 2009

Femtocells are viewed as a promising option for mobile operators to improve coverage and provide high-data-rate services in a cost-effective manner Femtocells can be used to serve indoor users, resulting in a powerful solution for ubiquitous indoor and outdoor coverage. TThe frequency accuracy and phase alignment is necessary for ensuring the quality of service (QoS) forapplications such as voice, real-time video, wireless hand-off, and data over a converged access medium at the femtocell. But, the GPS has some problem to be used at the femtocell, because it is difficult to set-up, depends on the satellite condition, and very expensive. The IEEE 1588 specification provides a low-cost means for clock synchronisation over a broadband Internet connection. The Time of Packet (ToP) specified in IEEE 1588 is able to synchronize distributed clocks with an accuracy of less than one microsecond in packet networks. However, the timing synchronization over packet switched networks is a difficult task because packet networks introduce large and highly variable packet delays. This paper proposes an enhanced filter algorithm to reduce ths packet delay variation effects and maintain ToP slave clock synchronization performance. The results are presented to demonstrate in the intra-networks and show the improved performance case when the efficient ToP filter algorithm is applied.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.2
• /
• pp.487-492
• /
• 2000

This paper presents a novel method of slip-compensation for rotor time constant variation in indirect field orientation control of induction motor drives. In field oriented control due to variation of rotor time constant, decoupling between the flux and torque components of stator current is lost and hence, the performance of operation of the machine deteriorates. To solve the problem, the q-axis is aligned to reference frame without phase difference by comparing the real flux component with the reference flux component. Then to compensate the slip, PI controller is used. The proposed method keeps a constant slip by compensating the gain of direct slip frequency when the rotor resistance of induction motor varies. To prove the validations of the proposed algorithm in the paper, computer simulations and experiments are executed.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.4
• /
• pp.143-148
• /
• 2017

Flash Memory which is light and strong external shock as storage of small electronics like smartphone, digital camera, car black box has been widely used. Since the operation speed of the read operation and the write operation are different from each other, and the flash memory has the feature that it is not possible to overwrite, the delete operation is added to solve these problems. Wear-leveling must also be considered, since the number of erase times of the flash memory is limited. Many studies have been conducted on the substitutional algorithms of flash memory based on these characteristics of recent flash memories. So, to solve the problem that has existing buffer replacement algorithm this thesis divide page into 6 groups and when proposed algorithm select victim page, it consider reference page frequency and page recency.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.23 no.3
• /
• pp.182-189
• /
• 2018

LLC resonant converters or phase-shift full-bridge converters have been widely used as DC - DC converters for rapid charging of electric vehicles (EVs). However, these converters present critical disadvantages, including a large circulating current, which can hinder efficiency and miniaturization in EV battery charger applications. In this paper, a new DC - DC converter topology is proposed for EV rapid chargers. The proposed converter can operate at high frequency despite a high rated power capacity of over 20kW, and the problem of circulating current can be minimized during the entire battery charging time. Owing to these advantages, the proposed converter can achieve a high conversion efficiency of over 97% for EV rapid charger applications. The performance of the proposed converter is verified with 20kW prototypes in this study.