• KIEAE Journal
• /
• v.10 no.5
• /
• pp.109-114
• /
• 2010

There are many business in complex building, and recently noise claims have increased in those buildings. It is one of the most desirable methods reducing the noise level to establish the noise criteria considering the admittable noise level between the source and receiving room, which are to be derived from the subjective response in the real conditions. Because the degree of annoyance and loudness for the intruding noises in complex building could be changed with background noise level, it is suggested to be researched the relationship between the noise levels and subjective response. In this study, the subjective response for three different background levels in receiving business or rooms were investigated for the typical eight business noise source including aerobic music. The results can be summarized as follows. In conditions of low background noise level(40 dB(A)), there is a tendency of intentionally attention situation (listening) in a subjective test. The other hand in conditions of relatively high background noise level(50 dB(A)), there is a unconscious situation (heraing). As the degree of moderately heard or annoyed in SD rating scale means that the noise is easily recognized in neighboring shops, usually the limit of noise criteria were decided on this rating point, so it will be reasonable to be adopted the criteria rating scale as slight heard or annoyed degree (SD criteria 3).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.25-37
• /
• 2002

모든 과학 및 공학분야에 걸쳐, 신호나 함수를 어떻게 표현하는 것이 바람직한 것인지에 대해서 많은 연구가 이루어져 왔다. 만약 신호나 함수를 적절하게 잘 표현하게 되면, 그것들 속에 내재된 의미있는 물리적 현상을 쉽게 파악할 수도 있고, 최소한의 함수나 데이터로 효과적으로 표현할 수도 있다. 지난 10여년 동안 비약적 발전을 해온 ‘웨이블렛’이라는 것도 신호나 함수를 표현하는 새로운 도구인데, 이것이 각광을 받고 있는 이유는 웨이블렛이 전통적인 표현방법이 제공하지 못하는 특성을 제공하기 때문이다.(중략)

• Journal of Hospice and Palliative Care
• /
• v.19 no.3
• /
• pp.201-210
• /
• 2016

Delirium is a common symptom in patients with terminal cancer. The prevalence increases in the dying phase. Delirium causes negative effects on quality of life for both patients and their families, and is associated with higher mortality. However, some studies reported that it tends to remain unrecognized in palliative care setting. That may be related with difficulties to distinguish the symptom from others with overlapping characteristics such as depression and dementia, and a lack of knowledge regarding assessment and diagnostic tools. We suggest that accurate recognition with validated tools and early diagnosis of the symptom should be highly prioritized in delirium management in palliative care setting. After diagnosing delirium, it is important to identify and address reversible precipitants such as medication, dehydration, and infection. Non-pharmacological interventions including comfortable environment for the patient and family education are also essential in the management strategy. If such interventions prove ineffective or insufficient to control hyperactive symptoms, pharmacologic interventions with antipsychotics and benzodiazepine can be considered. Until now, low levels of haloperidol remains the standard treatment despite a lack of evidence. Atypical antipsychotics such as olanzapine, quetiapine and risperidone reportedly have similar efficacy with a stronger sedating property and less adverse effect compared to haloperidol. Currently, delirium medications that can be used in palliative care setting require more clinical trials, and thus, clinical guidelines are not sufficiently available. We suggest that it is warranted to develop clinical guidelines based on well-designed clinical studies for palliative care patients.

• The Journal of the Acoustical Society of Korea
• /
• v.43 no.1
• /
• pp.9-18
• /
• 2024

The importance of active sonar systems is emerging due to the quietness of underwater targets and the increase in ambient noise due to the increase in maritime traffic. However, the low signal-to-noise ratio of the echo signal due to multipath propagation of the signal, various clutter, ambient noise and reverberation makes it difficult to identify underwater targets using active sonar. Attempts have been made to apply data-based methods such as machine learning or deep learning to improve the performance of underwater target recognition systems, but it is difficult to collect enough data for training due to the nature of sonar datasets. Methods based on mathematical modeling have been mainly used to compensate for insufficient active sonar data. However, methodologies based on mathematical modeling have limitations in accurately simulating complex underwater phenomena. Therefore, in this paper, we propose a sonar signal synthesis method based on a deep neural network. In order to apply the neural network model to the field of sonar signal synthesis, the proposed method appropriately corrects the attention-based encoder and decoder to the sonar signal, which is the main module of the Tacotron model mainly used in the field of speech synthesis. It is possible to synthesize a signal more similar to the actual signal by training the proposed model using the dataset collected by arranging a simulated target in an actual marine environment. In order to verify the performance of the proposed method, Perceptual evaluation of audio quality test was conducted and within score difference -2.3 was shown compared to actual signal in a total of four different environments. These results prove that the active sonar signal generated by the proposed method approximates the actual signal.

• Journal of the Korean Society of International Agriculture
• /
• v.30 no.4
• /
• pp.292-299
• /
• 2018

In a survey in which farmers were asked about their levels of satisfaction with agricultural machines, Japanese products scored higher than local products by 1.2, 1.3, and 1.4 times for tractors, combine harvesters, and rice transplanter, respectively. Japanese products corresponded to generally high satisfaction levels in terms of operating performance, operability, frequency of breakdowns, and durability, excluding sales price and after-sales services. Effective countermeasures through quality improvement are therefore necessary for Korean products. Furthermore, a survey of dealers showed that the components and consumables for core agricultural machines had high frequencies of breakdowns and repairs. Four major components of tractors represented 85.3% of all breakdowns and repairs, five components of combine harvesters represented 89.6%, and three components of rice transplanters represented 80.5%. Moreover, a comparison of the technological levels between local and imported machines showed that the local machines' levels were at 60-100% for tractors, 70-100% for combine harvesters, and 70-95% for rice transplanters. Small and mid-sized tractors, 4 interrow combine harvesters, and 6 interrow rice transplanters showed similar levels of technology. The results of the analysis suggest that action is urgently needed at a policy level to establish an agricultural machinery component research center for the development, production, and supply of commonly-used components, with the participation of manufacturers of agricultural machines and components, in order to enhance the competitiveness of local manufacturers and to revitalize the agricultural machine market.